Update version numbers for release

Cleanup whitespace

.readthedocs.yml

@@ -0,0 +1,17 @@
+# .readthedocs.yml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Build documentation in the documentation/ directory with Sphinx
+sphinx:
+  configuration: documentation/conf.py
+
+# Build documentation with MkDocs
+#mkdocs:
+#  configuration: mkdocs.yml
+
+# Optionally build your docs in additional formats such as PDF and ePub
+formats: all

.travis.yml

@@ -28,4 +28,3 @@ env:
  - BRBASE=7.0 RTEMS=4.9 TEST=NO
  - BRBASE=3.16
  - BRBASE=3.15
- - BRBASE=3.14

Doxyfile

@@ -38,7 +38,7 @@ PROJECT_NAME           = pvaClientCPP
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         =
+PROJECT_NUMBER         = 4.7.1
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
@@ -152,7 +152,7 @@ FULL_PATH_NAMES        = YES
 # will be relative from the directory where doxygen is started.
 # This tag requires that the tag FULL_PATH_NAMES is set to YES.
 
-STRIP_FROM_PATH        =
+STRIP_FROM_PATH        = src
 
 # The STRIP_FROM_INC_PATH tag can be used to strip a user-defined part of the
 # path mentioned in the documentation of a class, which tells the reader which
@@ -161,7 +161,7 @@ STRIP_FROM_PATH        =
 # specify the list of include paths that are normally passed to the compiler
 # using the -I flag.
 
-STRIP_FROM_INC_PATH    =
+STRIP_FROM_INC_PATH    = src
 
 # If the SHORT_NAMES tag is set to YES, doxygen will generate much shorter (but
 # less readable) file names. This can be useful is your file systems doesn't
@@ -765,7 +765,8 @@ WARN_LOGFILE           =
 # spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = include
+INPUT                  = src \
+                         src/pv
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
@@ -796,7 +797,7 @@ FILE_PATTERNS          =
 # be searched for input files as well.
 # The default value is: NO.
 
-RECURSIVE              = YES
+RECURSIVE              = NO
 
 # The EXCLUDE tag can be used to specify files and/or directories that should be
 # excluded from the INPUT source files. This way you can easily exclude a
@@ -1035,7 +1036,7 @@ GENERATE_HTML          = YES
 # The default directory is: html.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-HTML_OUTPUT            = documentation/html
+HTML_OUTPUT            = html/doxygen
 
 # The HTML_FILE_EXTENSION tag can be used to specify the file extension for each
 # generated HTML page (for example: .htm, .php, .asp).

configure/CONFIG_PVACLIENT_VERSION

@@ -1,3 +1,12 @@
+# Version number for the PVA Client API and shared library
+
 EPICS_PVACLIENT_MAJOR_VERSION = 4
-EPICS_PVACLIENT_MINOR_VERSION = 6
-EPICS_PVACLIENT_MAINTENANCE_VERSION = 0
+EPICS_PVACLIENT_MINOR_VERSION = 7
+EPICS_PVACLIENT_MAINTENANCE_VERSION = 1
+
+# Development flag, set to zero for release versions
+
+EPICS_PVACLIENT_DEVELOPMENT_FLAG = 0
+
+# Immediately after a release the MAINTENANCE_VERSION
+# will be incremented and the DEVELOPMENT_FLAG set to 1

documentation/RELEASE_NOTES.md

@@ -1,7 +1,20 @@
-# pvaClientCPP Module
+pwd# pvaClientCPP Module
 
 This document summarizes the changes to the module between releases.
 
+## Release 4.7.1 (EPICS 7.0.3.2 May 2020)
+
+* support access to a union field that is a scalar or scalarArray
+* fixed issues #62 and #63
+
+## Release 4.7.0 (EPICS 7.0.3.1, Nov 2019)
+
+* added JSON support for put and putGet
+* Fix for
+  [GitHub issue #62](https://github.com/epics-base/pvaClientCPP/issues/62)
+* Doxygen updates and read-the-docs integration.
+
+
 ## Release 4.6.0 (EPICS 7.0.3, Jul 2019)
 
 * pvaClient now handles exceptions from the server properly (issue #54).

documentation/_static/css/custom.css

@@ -0,0 +1,7 @@
+.wy-side-nav-search {
+    background-color: #18334B;
+}
+
+.wy-side-nav-search input[type="text"] {
+    border-color: #18334b;
+}

documentation/conf.py

@@ -0,0 +1,80 @@
+# Configuration file for the Sphinx documentation builder.
+#
+# This file only contains a selection of the most common options. For a full
+# list see the documentation:
+# http://www.sphinx-doc.org/en/master/config
+
+# -- Path setup --------------------------------------------------------------
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+# import os
+# import sys
+# sys.path.insert(0, os.path.abspath('.'))
+
+
+# -- Project information -----------------------------------------------------
+
+project = 'normativeTypes (C++)'
+copyright = '2019, EPICS Controls.'
+author = 'EPICS'
+
+
+# -- General configuration ---------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    'sphinx.ext.intersphinx',
+]
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This pattern also affects html_static_path and html_extra_path.
+exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+
+# Intersphinx links to subprojects
+intersphinx_mapping = {
+}
+
+
+# -- Options for HTML output -------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = 'sphinx_rtd_theme'
+
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+html_css_files = [
+    'css/custom.css',
+]
+
+master_doc = 'index'
+
+html_theme_options = {
+    'logo_only': True,
+}
+html_logo = "images/EPICS_white_logo_v02.png"
+
+html_extra_path = [
+    '../html',
+    'pvaClientCPP.html',
+]
+
+
+# -- Run Doxygen ------------------------------------------------------------
+
+import subprocess
+subprocess.call('cd ..; mkdir -p html/doxygen; doxygen', shell=True)

documentation/index.rst

@@ -0,0 +1,17 @@
+pvaClient (C++) Library
+========================
+
+.. toctree::
+   :hidden:
+
+   EPICS Website <https://epics-controls.org>
+   EPICS Documentation Home <https://docs.epics-controls.org>
+
+
+.. toctree::
+   :maxdepth: 1
+   :caption: pvaClientCPP
+
+   Reference Manual <https://docs.epics-controls.org/projects/pvaclient-cpp/en/latest/pvaClientCPP.html>
+   API Documentation <https://docs.epics-controls.org/projects/pvaclient-cpp/en/latest/doxygen>
+   Source Code Repository on GitHub <https://github.com/epics-base/pvaClientCPP>

src/pv/pvaClient.h

@@ -17,7 +17,8 @@
 
 #include <list>
 #include <iostream>
-#include <sstream>  
+#include <ostream>
+#include <sstream>
 #include <pv/requester.h>
 #include <pv/status.h>
 #include <pv/event.h>
@@ -35,12 +36,12 @@
 
 #ifdef pvaClientEpicsExportSharedSymbols
 #   define epicsExportSharedSymbols
-#	undef pvaClientEpicsExportSharedSymbols
+#   undef pvaClientEpicsExportSharedSymbols
 #endif
 
 #include <shareLib.h>
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 class PvaClient;
 typedef std::tr1::shared_ptr<PvaClient> PvaClientPtr;
@@ -160,7 +161,7 @@ public:
     PvaClientChannelPtr createChannel(
        std::string const & channelName,
        std::string const & providerName = "pva");
-    
+
     /** @brief Set a requester.
      *
      * The default is for PvaClient to handle messages by printing to System.out.
@@ -203,7 +204,7 @@ class PvaClientPutCache;
 typedef std::tr1::shared_ptr<PvaClientPutCache> PvaClientPutCachePtr;
 
 
-/** 
+/**
  * @brief A callback for change in connection status.
  *
  * <a href = "../htmldoxygen/pvaClientChannelStateChangeRequester.html">Overview of PvaClientChannelStateChangeRequester</a>
@@ -227,7 +228,7 @@ public:
     virtual void channelStateChange(PvaClientChannelPtr const & channel, bool isConnected) = 0;
 };
 
-/** 
+/**
  * @brief An easy to use alternative to directly calling the Channel methods of pvAccess.
  *
  * <a href = "../htmldoxygen/pvaClientChannel.html">Overview of PvaClientChannel</a>
@@ -244,7 +245,7 @@ public:
      */
     ~PvaClientChannel();
     /** @brief Set a client stateChangeRequester.
-     * 
+     *
      * @param stateChangeRequester The client stateChangeRequester implementation.
      */
     void setStateChangeRequester(PvaClientChannelStateChangeRequesterPtr const &stateChangeRequester);
@@ -289,7 +290,7 @@ public:
      * @throw runtime_error if failure.
      */
     PvaClientProcessPtr createProcess(std::string const & request = "");
-    /** Creates a PvaClientProcess. 
+    /** Creates a PvaClientProcess.
      *
      * @param pvRequest The syntax of pvRequest is defined by the copy facility of pvData.
      * @return The interface.
@@ -350,7 +351,7 @@ public:
     epics::pvData::shared_vector<const std::string>  getStringArray(
         std::string const & request = "field(value)");
     /** @brief create a PvaClientPut.
-     * 
+     *
      * Get a cached PvaClientPut or create and connect to a new PvaClientPut.
      * Then call it's get method.
      * @param request The syntax of request is defined by the copy facility of pvData.
@@ -396,7 +397,7 @@ public:
         epics::pvData::shared_vector<const double> const & value,
         std::string const & request = "field(value)");
     /** @brief Copy array to the value field.
-     * 
+     *
      * @param value The new value.
      * @param request The syntax of request is defined by the copy facility of pvData.
      * @throw runtime_error if failure.
@@ -449,7 +450,7 @@ public:
      * @throw runtime_error if failure.
      */
     PvaClientMonitorPtr monitor(std::string const & request = "field(value,alarm,timeStamp)");
-    /** @brief Call the next method with request =  "field(value,alarm,timeStamp)" 
+    /** @brief Call the next method with request =  "field(value,alarm,timeStamp)"
       *
       * @param pvaClientMonitorRequester The client callback.
       * @return The interface.
@@ -538,7 +539,7 @@ private:
     std::string channelName;
     std::string providerName;
     ConnectState connectState;
-    
+
     epics::pvData::CreateRequest::shared_pointer createRequest;
     PvaClientGetCachePtr pvaClientGetCache;
     PvaClientPutCachePtr pvaClientPutCache;
@@ -560,7 +561,7 @@ public:
     friend class PvaClient;
 };
 
-/** 
+/**
  *  @brief A base class for PvaClientGetData, PvaClientPutData, and PvaClientMonitorData.
  *
  * <a href = "../htmldoxygen/pvaClientData.html">Overview of PvaClientData</a>
@@ -613,6 +614,7 @@ public:
     void setData(
         epics::pvData::PVStructurePtr const & pvStructureFrom,
         epics::pvData::BitSetPtr const & bitSetFrom);
+
     /** @brief Is there a top level field named value.
      * @return The answer.
      */
@@ -679,6 +681,29 @@ public:
      * @return The timeStamp.
      */
     epics::pvData::TimeStamp getTimeStamp();
+    /** @brief parse from args
+     *
+     * Accepts arguments of the form json or field='value' where value is json syntax.
+     * field is name.name...
+     * @param args The arguments
+     * @throw runtime_error if failure.
+     */
+    void parse(const std::vector<std::string> &args);
+    /** @brief generate JSON output from the current PVStructure
+     *
+     * @param strm output stream
+     * @param ignoreUnprintable false or true; default is true.
+     * @param multiline false or true; default is false
+     *
+     * @throw runtime_error if failure.
+     */
+    void streamJSON(
+               std::ostream& strm,
+               bool ignoreUnprintable = true,
+               bool multiLine = false);
+     /** @brief set length of all array fields to 0
+     */
+    void zeroArrayLength();
     /** @brief Factory method for creating an instance of PvaClientData.
      *
      * NOTE: Not normally called by clients
@@ -688,15 +713,23 @@ public:
     static PvaClientDataPtr create(epics::pvData::StructureConstPtr const & structure);
 protected:
     PvaClientData(epics::pvData::StructureConstPtr const & structure);
+    epics::pvData::PVFieldPtr getSinglePVField();
     void checkValue();
     std::string messagePrefix;
 private:
+    void parse(
+        const std::string &arg,
+        const epics::pvData::PVFieldPtr &dest,
+        epics::pvData::BitSetPtr &bitSet);
+    void parse(
+        const std::string &arg,
+        const epics::pvData::PVUnionPtr &dest);
+    void zeroArrayLength(const epics::pvData::PVStructurePtr &pvStructure);
 
     epics::pvData::StructureConstPtr structure;
     epics::pvData::PVStructurePtr pvStructure;
     epics::pvData::BitSetPtr bitSet;
 
-    
     epics::pvData::PVFieldPtr pvValue;
     epics::pvData::PVAlarm pvAlarm;
     epics::pvData::PVTimeStamp pvTimeStamp;
@@ -704,7 +737,7 @@ private:
     friend class PvaClientPutGet;
 };
 
-/** 
+/**
  *  @brief A class that holds data returned by PvaClientGet or PvaClientPutGet
  *
  * <a href = "../htmldoxygen/pvaClientGetData.html">Overview of PvaClientGetData</a>
@@ -731,7 +764,7 @@ private:
 };
 
 class PvaClientPostHandlerPvt; // private to PvaClientPutData
-/** 
+/**
  *  @brief A class that holds data given to  by PvaClientPut or PvaClientPutGet
  *
  * <a href = "../htmldoxygen/pvaClientPutData.html">Overview of PvaClientPutData</a>
@@ -742,7 +775,7 @@ public:
     POINTER_DEFINITIONS(PvaClientPutData);
     /**
      * @brief Destructor
-     */    
+     */
     ~PvaClientPutData() {}
     /** @brief Put the value as a double.
      * @param value The new value.
@@ -795,7 +828,7 @@ public:
     POINTER_DEFINITIONS(PvaClientMonitorData);
     /**
      * @brief Destructor
-     */    
+     */
     ~PvaClientMonitorData() {}
     /** @brief Get the overrun BitSet for the pvStructure
      * This shows which fields have had more than one change.
@@ -881,7 +914,7 @@ public:
         PvaClientChannelPtr const & pvaClientChannel,
         epics::pvData::PVStructurePtr const &pvRequest
     );
-    
+
     /** @brief Destructor
      */
     ~PvaClientProcess();
@@ -935,7 +968,7 @@ private:
         PvaClientPtr const &pvaClient,
         PvaClientChannelPtr const & pvaClientChannel,
         epics::pvData::PVStructurePtr const &pvRequest);
-    
+
     void checkProcessState();
     enum ProcessConnectState {connectIdle,connectActive,connected};
 
@@ -1246,7 +1279,7 @@ private :
         PvaClientPtr const &pvaClient,
         PvaClientChannelPtr const & pvaClientChannel,
         epics::pvData::PVStructurePtr const &pvRequest);
-    
+
     void checkConnectState();
     enum PutConnectState {connectIdle,connectActive,connected};
 
@@ -1324,11 +1357,11 @@ public:
         PvaClientPutGetPtr const & clientPutGet)
     {
     }
-    
+
 };
 
 
-/** 
+/**
  * @brief An easy to use alternative to ChannelPutGet.
  *
  * <a href = "../htmldoxygen/pvaClientPutGet.html">Overview of PvaClientPutGet</a>
@@ -1415,11 +1448,11 @@ public:
     /** @brief Get the put data.
      * @return The interface.
      */
-    PvaClientPutDataPtr getPutData();   
+    PvaClientPutDataPtr getPutData();
     /** @brief Get the get data.
      * @return The interface.
      */
-    PvaClientGetDataPtr getGetData(); 
+    PvaClientGetDataPtr getGetData();
     /** @brief Get the PvaClientChannel;
      *
      * @return The interface.
@@ -1560,7 +1593,7 @@ public:
         std::string const & request,
         PvaClientChannelStateChangeRequesterPtr const & stateChangeRequester
             = PvaClientChannelStateChangeRequesterPtr(),
-        PvaClientMonitorRequesterPtr const & monitorRequester 
+        PvaClientMonitorRequesterPtr const & monitorRequester
             = PvaClientMonitorRequesterPtr()
     ) EPICS_DEPRECATED;
     /** @brief Destructor
@@ -1623,7 +1656,7 @@ public:
      *
      * @return The interface.
      */
-    PvaClientMonitorDataPtr getData();   
+    PvaClientMonitorDataPtr getData();
 private:
     std::string getRequesterName();
     void message(std::string const & message,epics::pvData::MessageType messageType);
@@ -1654,7 +1687,7 @@ private:
     epics::pvData::Status monitorConnectStatus;
     epics::pvData::MonitorPtr monitor;
     epics::pvData::MonitorElementPtr monitorElement;
-    
+
     PvaClientMonitorRequesterWPtr pvaClientMonitorRequester;
     MonitorConnectState connectState;
     bool userPoll;
@@ -1731,7 +1764,7 @@ public:
      * @brief Set a timeout for a request.
      * @param responseTimeout The time in seconds to wait for a request to complete.
      */
-    void setResponseTimeout(double responseTimeout) 
+    void setResponseTimeout(double responseTimeout)
     {
         this->responseTimeout = responseTimeout;
     }
@@ -1801,12 +1834,12 @@ private:
     PvaClient::weak_pointer pvaClient;
     epics::pvAccess::Channel::weak_pointer channel;
     epics::pvData::PVStructurePtr pvRequest;
-    
+
     epics::pvData::Mutex mutex;
     epics::pvData::Event waitForConnect;
     epics::pvData::Event waitForDone;
 
-    PvaClientRPCRequesterWPtr pvaClientRPCRequester;    
+    PvaClientRPCRequesterWPtr pvaClientRPCRequester;
     RPCRequesterImplPtr rpcRequester;
     epics::pvAccess::ChannelRPC::shared_pointer channelRPC;
     epics::pvData::PVStructurePtr pvResponse;
@@ -1825,6 +1858,5 @@ private:
 /** @page Overview Documentation
  *
  * <a href = "../pvaClientCPP.html">pvaClientCPP.html</a>
- *  
+ *
  */
-

src/pv/pvaClientMultiChannel.h

@@ -21,14 +21,14 @@
 
 #ifdef pvaClientMultiChannelEpicsExportSharedSymbols
 #   define epicsExportSharedSymbols
-#	undef pvaClientMultiChannelEpicsExportSharedSymbols
+#   undef pvaClientMultiChannelEpicsExportSharedSymbols
 #endif
 
 
 #include <pv/pvaClient.h>
 
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 
 class PvaClientMultiChannel;
@@ -115,7 +115,7 @@ public:
      * @brief create a pvaClientMultiGetDouble
      * @return The interface.
      */
-    PvaClientMultiGetDoublePtr createGet();   
+    PvaClientMultiGetDoublePtr createGet();
     /**
      * @brief Create a pvaClientMultiPutDouble.
      * @return The interface.
@@ -152,7 +152,7 @@ private:
         std::string const & providerName,
         size_t maxNotConnected);
     void checkConnected();
-    
+
     PvaClientPtr pvaClient;
     epics::pvData::shared_vector<const std::string> channelName;
     std::string providerName;
@@ -176,7 +176,7 @@ class epicsShareClass PvaClientMultiGetDouble :
 
 public:
     POINTER_DEFINITIONS(PvaClientMultiGetDouble);
-    
+
     /**
      * @brief Create a PvaClientMultiGetDouble.
      * @param pvaClientMultiChannel The interface to PvaClientMultiChannel.
@@ -214,7 +214,7 @@ private:
     PvaClientChannelArray pvaClientChannelArray;
     size_t nchannel;
     epics::pvData::Mutex mutex;
-    
+
     epics::pvData::shared_vector<double> doubleValue;
     std::vector<PvaClientGetPtr> pvaClientGet;
     bool isGetConnected;
@@ -229,7 +229,7 @@ class epicsShareClass PvaClientMultiPutDouble :
 
 public:
     POINTER_DEFINITIONS(PvaClientMultiPutDouble);
-   
+
     /** @brief Create a PvaClientMultiPutDouble.
      * @param pvaClientMultiChannel The interface to PvaClientMultiChannel.
      * @param pvaClientChannelArray The PvaClientChannel array.
@@ -277,7 +277,7 @@ class epicsShareClass PvaClientMultiMonitorDouble :
 
 public:
     POINTER_DEFINITIONS(PvaClientMultiMonitorDouble);
-    
+
     /** @brief Create a PvaClientMultiMonitorDouble.
      * @param pvaClientMultiChannel The interface to PvaClientMultiChannel.
      * @param pvaClientChannelArray The PvaClientChannel array.
@@ -388,8 +388,8 @@ private:
     epics::pvData::PVStructurePtr pvRequest;
     size_t nchannel;
     epics::pvData::Mutex mutex;
-    
-    
+
+
     PvaClientNTMultiDataPtr pvaClientNTMultiData;
     std::vector<PvaClientGetPtr> pvaClientGet;
     bool isConnected;
@@ -413,7 +413,7 @@ public:
     static PvaClientNTMultiPutPtr create(
          PvaClientMultiChannelPtr const &pvaClientMultiChannel,
          PvaClientChannelArray const &pvaClientChannelArray);
-     
+
     ~PvaClientNTMultiPut();
      /**
      * @brief Connect a channelPut for each channel.
@@ -543,15 +543,15 @@ public:
          PvaClientChannelArray const &pvaClientChannelArray,
          epics::pvData::PVStructurePtr const &  pvRequest);
     ~PvaClientNTMultiData();
-    
+
     /**
      * @brief Get the number of channels.
      * @return The number of channels.
      */
     size_t getNumber();
-   
+
     /**
-     * @brief Set the timeStamp base for computing deltaTimes. 
+     * @brief Set the timeStamp base for computing deltaTimes.
      */
     void startDeltaTime();
     /**
@@ -564,7 +564,7 @@ public:
      * @brief Get the time when the last get was made.
      * @return The timeStamp.
      */
-    epics::pvData::TimeStamp getTimeStamp(); 
+    epics::pvData::TimeStamp getTimeStamp();
     /**
      * @brief Get the  NTMultiChannel.
      * @return The value.
@@ -594,7 +594,7 @@ private:
     std::vector<epics::pvData::PVStructurePtr> topPVStructure;
     bool gotAlarm;
     bool gotTimeStamp;
-    
+
     epics::pvData::StructureConstPtr ntMultiChannelStructure;
     epics::pvData::shared_vector<epics::pvData::PVUnionPtr> unionValue;
     epics::pvData::shared_vector<epics::pvData::int32> severity;
@@ -615,4 +615,3 @@ private:
 }}
 
 #endif  /* PVACLIENTMULTICHANNEL_H */
-

src/pvaClient.cpp

@@ -23,7 +23,7 @@ using namespace epics::pvAccess;
 using namespace epics::pvAccess::ca;
 using namespace std;
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 
 class epicsShareClass PvaClientChannelCache
@@ -42,7 +42,7 @@ public:
 private:
     map<string,PvaClientChannelPtr> pvaClientChannelMap;
 };
-   
+
 PvaClientChannelPtr PvaClientChannelCache::getChannel(
     string const & channelName,
     string const & providerName)
@@ -77,7 +77,7 @@ void PvaClientChannelCache::showCache()
          string providerName = channel->getProvider()->getProviderName();
          cout << "channel " << channelName << " provider " << providerName << endl;
          pvaChannel->showCache();
-    } 
+    }
 }
 
 size_t PvaClientChannelCache::cacheSize()
@@ -137,7 +137,7 @@ PvaClient::PvaClient(std::string const & providerNames)
               }
              CAClientFactory::start();
              caStarted = true;
-         } else { 
+         } else {
              if(!channelRegistry->getProvider(providerName)) {
                  cerr << "PvaClient::get provider " << providerName  << " not known" << endl;
              }
@@ -191,7 +191,7 @@ PvaClientChannelPtr PvaClient::channel(
         std::string const & providerName,
         double timeOut)
 {
-    PvaClientChannelPtr pvaClientChannel = 
+    PvaClientChannelPtr pvaClientChannel =
         pvaClientChannelCache->getChannel(channelName,providerName);
     if(pvaClientChannel) return pvaClientChannel;
     pvaClientChannel = createChannel(channelName,providerName);
@@ -231,4 +231,3 @@ size_t PvaClient::cacheSize()
 }
 
 }}
- 

src/pvaClientChannel.cpp

@@ -183,7 +183,7 @@ void PvaClientChannel::channelCreated(const Status& status, Channel::shared_poin
         throw std::runtime_error(message);
     }
     if(channel->isConnected()) {
-        connectState = connected; 
+        connectState = connected;
         waitForConnect.signal();
     }
 }
@@ -267,7 +267,7 @@ void PvaClientChannel::connect(double timeout)
     Status status = waitConnect(timeout);
     if(status.isOK()) return;
     if(PvaClient::getDebug()) cout << "PvaClientChannel::connect  waitConnect failed\n";
-    string message = string("channel ") + channelName 
+    string message = string("channel ") + channelName
                     + " PvaClientChannel::connect " + status.getMessage();
     throw std::runtime_error(message);
 }
@@ -330,7 +330,7 @@ PvaClientProcessPtr PvaClientChannel::createProcess(string const & request)
 {
     PVStructurePtr pvRequest = createRequest->createRequest(request);
     if(!pvRequest) {
-        string message = string("channel ") + channelName 
+        string message = string("channel ") + channelName
             + " PvaClientChannel::createProcess invalid pvRequest: "
             + createRequest->getMessage();
         throw std::runtime_error(message);
@@ -364,7 +364,7 @@ PvaClientGetPtr PvaClientChannel::createGet(string const & request)
 {
     PVStructurePtr pvRequest = createRequest->createRequest(request);
     if(!pvRequest) {
-        string message = string("channel ") + channelName 
+        string message = string("channel ") + channelName
             + " PvaClientChannel::createGet invalid pvRequest: "
             + createRequest->getMessage();
         throw std::runtime_error(message);
@@ -419,7 +419,7 @@ PvaClientPutPtr PvaClientChannel::createPut(string const & request)
 {
     PVStructurePtr pvRequest = createRequest->createRequest(request);
     if(!pvRequest) {
-        string message = string("channel ") + channelName 
+        string message = string("channel ") + channelName
             + " PvaClientChannel::createPut invalid pvRequest: "
             + createRequest->getMessage();
         throw std::runtime_error(message);
@@ -477,7 +477,7 @@ PvaClientPutGetPtr PvaClientChannel::createPutGet(string const & request)
 {
     PVStructurePtr pvRequest = createRequest->createRequest(request);
     if(!pvRequest) {
-        string message = string("channel ") + channelName 
+        string message = string("channel ") + channelName
             + " PvaClientChannel::createPutGet invalid pvRequest: "
             + createRequest->getMessage();
         throw std::runtime_error(message);
@@ -499,7 +499,7 @@ PvaClientArrayPtr PvaClientChannel::createArray(string const & request)
 {
     PVStructurePtr pvRequest = createRequest->createRequest(request);
     if(!pvRequest) {
-        string message = string("channel ") + channelName 
+        string message = string("channel ") + channelName
             + " PvaClientChannel::createArray invalid pvRequest: "
             + createRequest->getMessage();
         throw std::runtime_error(message);
@@ -541,7 +541,7 @@ PvaClientMonitorPtr PvaClientChannel::createMonitor(string const & request)
 {
     PVStructurePtr pvRequest = createRequest->createRequest(request);
     if(!pvRequest) {
-        string message = string("channel ") + channelName 
+        string message = string("channel ") + channelName
             + " PvaClientChannel::createMonitor invalid pvRequest: "
             + createRequest->getMessage();
         throw std::runtime_error(message);
@@ -561,7 +561,7 @@ PVStructurePtr PvaClientChannel::rpc(
     PVStructurePtr const &  pvRequest,
     PVStructurePtr const & pvArgument)
 {
-    
+
     PvaClientRPCPtr rpc = createRPC(pvRequest);
     return rpc->request(pvArgument);
 }

src/pvaClientData.cpp

@@ -11,9 +11,17 @@
 
 #include <typeinfo>
 #include <sstream>
+#include <istream>
+#include <ostream>
 
 #include <pv/createRequest.h>
 #include <pv/convert.h>
+#include <pv/pvEnumerated.h>
+
+#if EPICS_VERSION_INT>=VERSION_INT(3,15,0,1)
+#  include <pv/json.h>
+#  define USE_JSON
+#endif
 
 #define epicsExportSharedSymbols
 
@@ -49,6 +57,30 @@ PvaClientData::PvaClientData(StructureConstPtr const & structure)
 {
 }
 
+PVFieldPtr PvaClientData::getSinglePVField()
+{
+    if(PvaClient::getDebug()) cout << "PvaClientData::getSinglePVField\n";
+    PVStructurePtr pvStructure = getPVStructure();
+    while(true) {
+         const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
+         if(fieldPtrArray.size()==0) {
+              throw std::logic_error("PvaClientData::getSinglePVField() pvRequest for empty structure");
+         }
+         if(fieldPtrArray.size()!=1) {
+              PVFieldPtr pvValue  = pvStructure->getSubField("value");
+              if(pvValue) {
+                  Type type = pvValue->getField()->getType();
+                  if(type!=epics::pvData::structure) return pvValue;
+              }
+              throw std::logic_error("PvaClientData::getSinglePVField() pvRequest for multiple fields");
+         }
+         PVFieldPtr pvField(fieldPtrArray[0]);
+         Type type = pvField->getField()->getType();
+         if(type!=epics::pvData::structure) return pvField;
+         pvStructure = static_pointer_cast<PVStructure>(pvField);
+    }
+}
+
 void PvaClientData::checkValue()
 {
     if(PvaClient::getDebug()) cout << "PvaClientData::checkValue\n";
@@ -106,6 +138,7 @@ void PvaClientData::setData(
    pvValue = pvStructure->getSubField("value");
 }
 
+
 bool PvaClientData::hasValue()
 {
     if(PvaClient::getDebug()) cout << "PvaClientData::hasValue\n";
@@ -171,34 +204,12 @@ PVScalarArrayPtr  PvaClientData::getScalarArrayValue()
 double PvaClientData::getDouble()
 {
     if(PvaClient::getDebug()) cout << "PvaClientData::getDouble\n";
-    PVScalarPtr pvScalar;
-    PVStructurePtr pvStructure = getPVStructure();
-    PVFieldPtr pvValue  = pvStructure->getSubField("value");
-    if(pvValue) {
-        Type type = pvValue->getField()->getType();
-        if(type==scalar) pvScalar = static_pointer_cast<PVScalar>(pvValue);
-    }
-    if(!pvScalar) {
-        while(true) {
-             const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
-             if(fieldPtrArray.size()!=1) {
-                  throw std::logic_error(
-                      "PvaClientData::getDouble() pvRequest for multiple fields");
-             }
-             PVFieldPtr pvField(fieldPtrArray[0]);
-             Type type = pvField->getField()->getType();
-             if(type==scalar) {
-                 pvScalar = static_pointer_cast<PVScalar>(pvField);
-                 break;
-             }
-             if(pvField->getField()->getType()!=epics::pvData::structure) break;
-             pvStructure = static_pointer_cast<PVStructure>(pvField);
-        }
-    }
-    if(!pvScalar) {
-        throw std::logic_error(
-            "PvaClientData::getDouble() did not find a scalar field");
+    PVFieldPtr pvField = getSinglePVField();
+    Type type = pvField->getField()->getType();
+    if(type!=scalar) {
+        throw std::logic_error("PvaClientData::getDouble() did not find a scalar field");
     }
+    PVScalarPtr pvScalar = static_pointer_cast<PVScalar>(pvField);
     ScalarType scalarType = pvScalar->getScalar()->getScalarType();
     if(scalarType==pvDouble) {
         PVDoublePtr pvDouble = static_pointer_cast<PVDouble>(pvScalar);
@@ -214,70 +225,24 @@ double PvaClientData::getDouble()
 string PvaClientData::getString()
 {
     if(PvaClient::getDebug()) cout << "PvaClientData::getString\n";
-    PVScalarPtr pvScalar;
-    PVStructurePtr pvStructure = getPVStructure();
-    PVFieldPtr pvValue  = pvStructure->getSubField("value");
-    if(pvValue) {
-        Type type = pvValue->getField()->getType();
-        if(type==scalar) pvScalar = static_pointer_cast<PVScalar>(pvValue);
-    }
-    if(!pvScalar) {
-        while(true) {
-             const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
-             if(fieldPtrArray.size()!=1) {
-                  throw std::logic_error(
-                      "PvaClientData::getString() pvRequest for multiple fields");
-             }
-             PVFieldPtr pvField(fieldPtrArray[0]);
-             Type type = pvField->getField()->getType();
-             if(type==scalar) {
-                 pvScalar = static_pointer_cast<PVScalar>(pvField);
-                 break;
-             }
-             if(pvField->getField()->getType()!=epics::pvData::structure) break;
-             pvStructure = static_pointer_cast<PVStructure>(pvField);
-        }
-    }
-    if(!pvScalar) {
-        throw std::logic_error(
-            "PvaClientData::getString() did not find a scalar field");
+    PVFieldPtr pvField = getSinglePVField();
+    Type type = pvField->getField()->getType();
+    if(type!=scalar) {
+        throw std::logic_error("PvaClientData::getString() did not find a scalar field");
     }
+    PVScalarPtr pvScalar = static_pointer_cast<PVScalar>(pvField);
     return convert->toString(pvScalar);
 }
 
 shared_vector<const double> PvaClientData::getDoubleArray()
 {
     if(PvaClient::getDebug()) cout << "PvaClientData::getDoubleArray\n";
-    PVScalarArrayPtr pvScalarArray;
-    PVStructurePtr pvStructure = getPVStructure();
-    PVFieldPtr pvValue  = pvStructure->getSubField("value");
-    if(pvValue) {
-        Type type = pvValue->getField()->getType();
-        if(type==scalarArray) {
-            pvScalarArray = static_pointer_cast<PVScalarArray>(pvValue);
-        }
-    }
-    if(!pvScalarArray) {
-        while(true) {
-             const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
-             if(fieldPtrArray.size()!=1) {
-                  throw std::logic_error(
-                      "PvaClientData::getDoubleArray() pvRequest for multiple fields");
-             }
-             PVFieldPtr pvField(fieldPtrArray[0]);
-             Type type = pvField->getField()->getType();
-             if(type==scalarArray) {
-                 pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
-                 break;
-             }
-             if(pvField->getField()->getType()!=epics::pvData::structure) break;
-             pvStructure = static_pointer_cast<PVStructure>(pvField);
-        }
-    }
-    if(!pvScalarArray) {
-        throw std::logic_error(
-            "PvaClientData::getDoubleArray() did not find a scalarArray field");
+    PVFieldPtr pvField = getSinglePVField();
+    Type type = pvField->getField()->getType();
+    if(type!=scalarArray) {
+        throw std::logic_error("PvaClientData::getDoubleArray() did not find a scalarArray field");
     }
+    PVScalarArrayPtr pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
     ScalarType scalarType = pvScalarArray->getScalarArray()->getElementType();
     if(!ScalarTypeFunc::isNumeric(scalarType)) {
         throw std::logic_error(
@@ -291,36 +256,12 @@ shared_vector<const double> PvaClientData::getDoubleArray()
 shared_vector<const string> PvaClientData::getStringArray()
 {
     if(PvaClient::getDebug()) cout << "PvaClientData::getStringArray\n";
-    PVScalarArrayPtr pvScalarArray;
-    PVStructurePtr pvStructure = getPVStructure();
-    PVFieldPtr pvValue  = pvStructure->getSubField("value");
-    if(pvValue) {
-       Type type = pvValue->getField()->getType();
-        if(type==scalarArray) {
-             pvScalarArray = static_pointer_cast<PVScalarArray>(pvValue);
-        }
-    }
-    if(!pvScalarArray) {
-        while(true) {
-             const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
-             if(fieldPtrArray.size()!=1) {
-                  throw std::logic_error(
-                      "PvaClientData::getStringArray() pvRequest for multiple fields");
-             }
-             PVFieldPtr pvField(fieldPtrArray[0]);
-             Type type = pvField->getField()->getType();
-             if(type==scalarArray) {
-                 pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
-                 break;
-             }
-             if(pvField->getField()->getType()!=epics::pvData::structure) break;
-             pvStructure = static_pointer_cast<PVStructure>(pvField);
-        }
-    }
-    if(!pvScalarArray) {
-        throw std::logic_error(
-            "PvaClientData::getStringArray() did not find a scalarArray field");
+    PVFieldPtr pvField = getSinglePVField();
+    Type type = pvField->getField()->getType();
+    if(type!=scalarArray) {
+        throw std::logic_error("PvaClientData::getStringArray() did not find a scalarArray field");
     }
+    PVScalarArrayPtr pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
     shared_vector<const string> retValue;
     pvScalarArray->getAs<const string>(retValue);
     return retValue;
@@ -358,4 +299,142 @@ TimeStamp PvaClientData::getTimeStamp()
    throw std::runtime_error(messagePrefix + noTimeStamp);
 }
 
+void PvaClientData::zeroArrayLength()
+{
+    if(!pvStructure) throw new std::runtime_error(messagePrefix + noStructure);
+    zeroArrayLength(pvStructure);
+}
+void PvaClientData::parse(
+    const std::string &arg,const PVFieldPtr &dest,BitSetPtr & bitSet)
+{
+#ifdef USE_JSON
+    std::istringstream strm(arg);
+    parseJSON(strm, dest,&(*bitSet));
+#else
+    throw std::runtime_error("JSON support not built");
+#endif
+}
+
+void PvaClientData::parse(
+    const std::string &arg,const PVUnionPtr &pvUnion)
+{
+    if(pvUnion->getUnion()->isVariant()) {
+          throw std::runtime_error(messagePrefix + "varient union not implemented");
+    }
+    size_t iequals = arg.find_first_of('=');
+    string field;
+    string rest;
+    if(iequals==std::string::npos) {
+        string mess(arg);
+        mess += " was expected to start with field=";
+          throw std::runtime_error(messagePrefix + mess);
+    }
+    field = arg.substr(0,iequals);
+    rest = arg.substr(iequals+1);
+    PVFieldPtr pvField(pvUnion->select(field));
+    if(pvField->getField()->getType()==epics::pvData::union_) {
+        PVUnionPtr pvu = static_pointer_cast<PVUnion>(pvField);
+        parse(rest,pvu);
+        return;
+    }
+    BitSetPtr bs;
+    parse(rest,pvField,bs);
+    return;
+}
+
+void PvaClientData::parse(const std::vector<std::string> &args)
+{
+    if(!pvStructure) throw std::runtime_error(messagePrefix + noStructure);
+    if(!bitSet) throw std::runtime_error(messagePrefix + noStructure);
+    size_t num = args.size();
+    if(num<1) throw std::runtime_error(messagePrefix + " no arguments");
+    for(size_t i=0; i<num; ++i)
+    {
+        string val = args[i];
+        size_t iequals = val.find_first_of('=');
+        string field;
+        string rest(val);
+        if(iequals==std::string::npos) {
+           parse(rest,pvStructure,bitSet);
+           continue;
+        }
+        field = val.substr(0,iequals);
+        rest = val.substr(iequals+1);
+        if(field.size()==std::string::npos) {
+           parse(rest,pvStructure,bitSet);
+           continue;
+        }
+        PVFieldPtr pvField(pvStructure->getSubField(field));
+        if(!pvField) throw std::runtime_error(messagePrefix + field +" does not exist");
+        // look for enumerated structure
+        PVEnumerated pvEnumerated;
+        bool result = pvEnumerated.attach(pvField);
+        if(result) {
+             PVStringArray::const_svector choices(pvEnumerated.getChoices());
+             for(size_t i=0; i<choices.size(); ++i) {
+                  if(choices[i]==rest) {
+                     pvEnumerated.setIndex(i);
+                     return;
+                  }
+             }
+        }
+        // look for union
+        PVUnionPtr pvUnion(pvStructure->getSubField<PVUnion>(field));
+        if(pvUnion) {
+            parse(rest,pvUnion);
+            bitSet->set(pvUnion->getFieldOffset());
+            return;
+        }
+        parse(rest,pvField,bitSet);
+    }
+}
+
+void PvaClientData::streamJSON(
+               std::ostream& strm,
+               bool ignoreUnprintable,
+               bool multiLine)
+{
+#ifdef USE_JSON
+    JSONPrintOptions opts;
+    opts.ignoreUnprintable = ignoreUnprintable;
+    opts.multiLine = multiLine;
+    printJSON(strm,*pvStructure,*bitSet,opts);
+#else
+    throw std::runtime_error("JSON support not built");
+#endif
+}
+
+
+void PvaClientData::zeroArrayLength(const epics::pvData::PVStructurePtr &pvStructure)
+{
+const PVFieldPtrArray pvFields(pvStructure->getPVFields());
+    for(size_t i=0; i<pvFields.size(); ++i) {
+        PVFieldPtr pvField = pvFields[i];
+        Type type(pvField->getField()->getType());
+        switch(type) {
+        case epics::pvData::scalarArray:
+            {
+                PVScalarArrayPtr pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
+                pvScalarArray->setLength(0);
+            }
+            break;
+        case epics::pvData::structureArray:
+            {
+                PVStructureArrayPtr pvStructureArray = static_pointer_cast<PVStructureArray>(pvField);
+                pvStructureArray->setLength(0);
+            }
+            break;
+        case epics::pvData::structure:
+            {
+                PVStructurePtr pvStructure = static_pointer_cast<PVStructure>(pvField);
+                zeroArrayLength(pvStructure);
+            }
+            break;
+        default:
+               break;
+        }
+    }
+}
+
+
 }}

src/pvaClientGet.cpp

@@ -55,7 +55,7 @@ public:
     {
         PvaClientGetPtr clientGet(pvaClientGet.lock());
         if(!clientGet) return;
-        clientGet->channelGetConnect(status,channelGet,structure);  
+        clientGet->channelGetConnect(status,channelGet,structure);
     }
 
     virtual void getDone(
@@ -182,7 +182,7 @@ void PvaClientGet::channelGetConnect(
           req->channelGetConnect(status,shared_from_this());
     }
     waitForConnect.signal();
-    
+
 }
 
 void PvaClientGet::getDone(

src/pvaClientMonitor.cpp

@@ -57,21 +57,21 @@ public:
     {
         PvaClientMonitorPtr clientMonitor(pvaClientMonitor.lock());
         if(!clientMonitor) return;
-        clientMonitor->monitorConnect(status,monitor,structure);  
+        clientMonitor->monitorConnect(status,monitor,structure);
     }
 
     virtual void unlisten(epics::pvData::MonitorPtr const & monitor)
     {
         PvaClientMonitorPtr clientMonitor(pvaClientMonitor.lock());
         if(!clientMonitor) return;
-        clientMonitor->unlisten(monitor);  
+        clientMonitor->unlisten(monitor);
     }
 
     virtual void monitorEvent(epics::pvData::MonitorPtr const & monitor)
     {
         PvaClientMonitorPtr clientMonitor(pvaClientMonitor.lock());
         if(!clientMonitor) return;
-        clientMonitor->monitorEvent(monitor);  
+        clientMonitor->monitorEvent(monitor);
     }
 };
 
@@ -131,7 +131,7 @@ PvaClientMonitor::PvaClientMonitor(
 {
     if(PvaClient::getDebug()) {
          cout<< "PvaClientMonitor::PvaClientMonitor\n"
-             << " channelName " << pvaClientChannel->getChannel()->getChannelName() 
+             << " channelName " << pvaClientChannel->getChannel()->getChannelName()
              << endl;
     }
 }
@@ -276,7 +276,7 @@ void PvaClientMonitor::monitorEvent(MonitorPtr const & monitor)
         cout << "PvaClientMonitor::monitorEvent"
            << " channelName " << pvaClientChannel->getChannel()->getChannelName()
            << endl;
-    }    
+    }
     PvaClientMonitorRequesterPtr req = pvaClientMonitorRequester.lock();
     if(req) req->event(shared_from_this());
     if(userWait) waitForEvent.signal();
@@ -300,7 +300,7 @@ void PvaClientMonitor::connect()
     issueConnect();
     Status status = waitConnect();
     if(status.isOK()) return;
-    string message = string("channel ") 
+    string message = string("channel ")
         + pvaClientChannel->getChannel()->getChannelName()
         + " PvaClientMonitor::connect "
         + status.getMessage();

src/pvaClientMultiChannel.cpp

@@ -80,7 +80,7 @@ Status PvaClientMultiChannel::connect(double timeout)
     Status status = Status::Ok;
     size_t numBad = 0;
     for(size_t i=0; i< numChannel; ++i) {
-	if(numBad==0) {
+        if(numBad==0) {
             status = pvaClientChannelArray[i]->waitConnect(timeout);
         } else {
             status = pvaClientChannelArray[i]->waitConnect(.001);
@@ -140,7 +140,7 @@ PvaClientPtr PvaClientMultiChannel::getPvaClient()
     return pvaClient;
 }
 
- 
+
 
 PvaClientMultiGetDoublePtr PvaClientMultiChannel::createGet()
 {

src/pvaClientMultiGetDouble.cpp

@@ -21,7 +21,7 @@ using namespace epics::pvAccess;
 using namespace epics::nt;
 using namespace std;
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 
 PvaClientMultiGetDoublePtr PvaClientMultiGetDouble::create(
@@ -79,7 +79,7 @@ epics::pvData::shared_vector<double> PvaClientMultiGetDouble::get()
 {
     if(!isGetConnected) connect();
     shared_vector<epics::pvData::boolean> isConnected = pvaClientMultiChannel->getIsConnected();
-    
+
     for(size_t i=0; i<nchannel; ++i)
     {
          if(isConnected[i]) {
@@ -96,7 +96,7 @@ epics::pvData::shared_vector<double> PvaClientMultiGetDouble::get()
                throw std::runtime_error(message);
          }
     }
-    
+
     for(size_t i=0; i<nchannel; ++i)
     {
         if(isConnected[i])

src/pvaClientMultiMonitorDouble.cpp

@@ -21,7 +21,7 @@ using namespace epics::pvAccess;
 using namespace epics::nt;
 using namespace std;
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 
 PvaClientMultiMonitorDoublePtr PvaClientMultiMonitorDouble::create(

src/pvaClientMultiPutDouble.cpp

@@ -21,7 +21,7 @@ using namespace epics::pvAccess;
 using namespace epics::nt;
 using namespace std;
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 
 PvaClientMultiPutDoublePtr PvaClientMultiPutDouble::create(

src/pvaClientNTMultiData.cpp

@@ -20,7 +20,7 @@ using namespace epics::pvAccess;
 using namespace epics::nt;
 using namespace std;
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 PvaClientNTMultiDataPtr PvaClientNTMultiData::create(
     epics::pvData::UnionConstPtr const & u,
@@ -63,7 +63,7 @@ PvaClientNTMultiData::PvaClientNTMultiData(
          severity.resize(nchannel);
          status.resize(nchannel);
          message.resize(nchannel);
-         
+
     }
     if(pvRequest->getSubField("field.timeStamp")) {
         gotTimeStamp = true;
@@ -165,7 +165,7 @@ void PvaClientNTMultiData::endDeltaTime(bool valueOnly)
                     userTag[i] = pvTag->get();
                 }
             }
-        } 
+        }
     }
 }
 

src/pvaClientNTMultiGet.cpp

@@ -20,7 +20,7 @@ using namespace epics::pvAccess;
 using namespace epics::nt;
 using namespace std;
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 
 PvaClientNTMultiGetPtr PvaClientNTMultiGet::create(
@@ -75,7 +75,7 @@ void PvaClientNTMultiGet::connect()
          if(isConnected[i]) {
                Status status = pvaClientGet[i]->waitConnect();
                if(status.isOK()) continue;
-               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName() 
+               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName()
                     + " PvaChannelGet::waitConnect " + status.getMessage();
                throw std::runtime_error(message);
          }
@@ -87,7 +87,7 @@ void PvaClientNTMultiGet::get(bool valueOnly)
 {
     if(!isConnected) connect();
     shared_vector<epics::pvData::boolean> isConnected = pvaClientMultiChannel->getIsConnected();
-    
+
     for(size_t i=0; i<nchannel; ++i)
     {
          if(isConnected[i]) {
@@ -99,7 +99,7 @@ void PvaClientNTMultiGet::get(bool valueOnly)
          if(isConnected[i]) {
                Status status = pvaClientGet[i]->waitGet();
                if(status.isOK()) continue;
-               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName() 
+               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName()
                     + " PvaChannelGet::waitGet " + status.getMessage();
                throw std::runtime_error(message);
          }

src/pvaClientNTMultiMonitor.cpp

@@ -23,7 +23,7 @@ using namespace epics::pvAccess;
 using namespace epics::nt;
 using namespace std;
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 PvaClientNTMultiMonitorPtr PvaClientNTMultiMonitor::create(
     PvaClientMultiChannelPtr const &pvaMultiChannel,
@@ -79,7 +79,7 @@ void PvaClientNTMultiMonitor::connect()
          if(isConnected[i]) {
                Status status = pvaClientMonitor[i]->waitConnect();
                if(status.isOK()) continue;
-               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName() 
+               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName()
                     + " PvaChannelMonitor::waitConnect " + status.getMessage();
                throw std::runtime_error(message);
          }

src/pvaClientNTMultiPut.cpp

@@ -22,7 +22,7 @@ using namespace epics::pvAccess;
 using namespace epics::nt;
 using namespace std;
 
-namespace epics { namespace pvaClient { 
+namespace epics { namespace pvaClient {
 
 PvaClientNTMultiPutPtr PvaClientNTMultiPut::create(
     PvaClientMultiChannelPtr const &pvaMultiChannel,
@@ -67,7 +67,7 @@ void PvaClientNTMultiPut::connect()
          if(isConnected[i]) {
                Status status = pvaClientPut[i]->waitConnect();
                if(status.isOK()) continue;
-               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName() 
+               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName()
                     + " PvaChannelPut::waitConnect " + status.getMessage();
                throw std::runtime_error(message);
          }
@@ -83,7 +83,7 @@ void PvaClientNTMultiPut::connect()
          if(isConnected[i]) {
                Status status = pvaClientPut[i]->waitGet();
                if(status.isOK()) continue;
-               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName() 
+               string message = string("channel ") +pvaClientChannelArray[i]->getChannelName()
                     + " PvaChannelPut::waitGet " + status.getMessage();
                throw std::runtime_error(message);
          }
@@ -121,9 +121,9 @@ void PvaClientNTMultiPut::put()
          if(isConnected[i]) {
               Status status = pvaClientPut[i]->waitPut();
               if(status.isOK())  continue;
-              string message = string("channel ") +pvaClientChannelArray[i]->getChannelName() 
+              string message = string("channel ") +pvaClientChannelArray[i]->getChannelName()
                     + " PvaChannelPut::waitPut " + status.getMessage();
-              throw std::runtime_error(message); 
+              throw std::runtime_error(message);
          }
     }
 }

src/pvaClientProcess.cpp

@@ -54,7 +54,7 @@ public:
     {
         PvaClientProcessPtr clientProcess(pvaClientProcess.lock());
         if(!clientProcess) return;
-        clientProcess->channelProcessConnect(status,channelProcess);  
+        clientProcess->channelProcessConnect(status,channelProcess);
     }
 
     virtual void processDone(
@@ -156,7 +156,7 @@ void PvaClientProcess::channelProcessConnect(
           req->channelProcessConnect(status,shared_from_this());
     }
     waitForConnect.signal();
-    
+
 }
 
 void PvaClientProcess::processDone(
@@ -174,7 +174,7 @@ void PvaClientProcess::processDone(
         channelProcessStatus = status;
         processState = processComplete;
     }
-    
+
     PvaClientProcessRequesterPtr  req(pvaClientProcessRequester.lock());
     if(req) {
           req->processDone(status,shared_from_this());

src/pvaClientPut.cpp

@@ -55,7 +55,7 @@ public:
     {
         PvaClientPutPtr clientPut(pvaClientPut.lock());
         if(!clientPut) return;
-        clientPut->channelPutConnect(status,channelPut,structure);  
+        clientPut->channelPutConnect(status,channelPut,structure);
     }
 
     virtual void getDone(
@@ -183,7 +183,7 @@ void PvaClientPut::channelPutConnect(
           req->channelPutConnect(status,shared_from_this());
     }
     waitForConnect.signal();
-    
+
 }
 
 void PvaClientPut::getDone(
@@ -249,7 +249,7 @@ void PvaClientPut::connect()
     issueConnect();
     Status status = waitConnect();
     if(status.isOK()) return;
-    string message = string("channel ") 
+    string message = string("channel ")
         + pvaClientChannel->getChannel()->getChannelName()
         + " PvaClientPut::connect "
         + status.getMessage();
@@ -271,7 +271,7 @@ void PvaClientPut::issueConnect()
     connectState = connectActive;
     channelPutConnectStatus = Status(Status::STATUSTYPE_ERROR, "connect active");
     channelPut = pvaClientChannel->getChannel()->createChannelPut(channelPutRequester,pvRequest);
-       
+
 }
 
 Status PvaClientPut::waitConnect()
@@ -308,7 +308,7 @@ void PvaClientPut::get()
     issueGet();
     Status status = waitGet();
     if(status.isOK()) return;
-    string message = string("channel ") 
+    string message = string("channel ")
         +  pvaClientChannel->getChannel()->getChannelName()
         + " PvaClientPut::get "
         + status.getMessage();
@@ -376,7 +376,7 @@ void PvaClientPut::issuePut()
     if(PvaClient::getDebug()) {
         cout << "PvaClientPut::issuePut"
            << " channelName " << pvaClientChannel->getChannel()->getChannelName()
-           << " pvStructure\n" << pvaClientData->getPVStructure() 
+           << " pvStructure\n" << pvaClientData->getPVStructure()
            << " bitSet " << *pvaClientData->getChangedBitSet() << endl
            << endl;
     }

src/pvaClientPutData.cpp

@@ -74,34 +74,12 @@ PvaClientPutData::PvaClientPutData(StructureConstPtr const & structure)
 void PvaClientPutData::putDouble(double value)
 {
     if(PvaClient::getDebug()) cout << "PvaClientPutData::putDouble\n";
-    PVScalarPtr pvScalar;
-    PVStructurePtr pvStructure = getPVStructure();
-    PVFieldPtr pvValue  = pvStructure->getSubField("value");
-    if(pvValue) {
-        Type type = pvValue->getField()->getType();
-        if(type==scalar) pvScalar = static_pointer_cast<PVScalar>(pvValue);
-    }
-    if(!pvScalar) {
-        while(true) {
-             const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
-             if(fieldPtrArray.size()!=1) {
-                  throw std::logic_error(
-                      "PvaClientData::putDouble() pvRequest for multiple fields");
-             }
-             PVFieldPtr pvField(fieldPtrArray[0]);
-             Type type = pvField->getField()->getType();
-             if(type==scalar) {
-                 pvScalar = static_pointer_cast<PVScalar>(pvField);
-                 break;
-             }
-             if(pvField->getField()->getType()!=epics::pvData::structure) break;
-             pvStructure = static_pointer_cast<PVStructure>(pvField);
-        }
-    }
-    if(!pvScalar) {
-        throw std::logic_error(
-            "PvaClientData::putDouble() did not find a scalar field");
+    PVFieldPtr pvField = getSinglePVField();
+    Type type = pvField->getField()->getType();
+    if(type!=scalar) {
+        throw std::logic_error("PvaClientData::putDouble() did not find a scalar field");
     }
+    PVScalarPtr pvScalar = static_pointer_cast<PVScalar>(pvField);
     ScalarType scalarType = pvScalar->getScalar()->getScalarType();
     if(scalarType==pvDouble) {
         PVDoublePtr pvDouble = static_pointer_cast<PVDouble>(pvScalar);
@@ -118,70 +96,24 @@ void PvaClientPutData::putDouble(double value)
 void PvaClientPutData::putString(std::string const & value)
 {
     if(PvaClient::getDebug()) cout << "PvaClientPutData::putString\n";
-    PVScalarPtr pvScalar;
-    PVStructurePtr pvStructure = getPVStructure();
-    PVFieldPtr pvValue  = pvStructure->getSubField("value");
-    if(pvValue) {
-        Type type = pvValue->getField()->getType();
-        if(type==scalar) pvScalar = static_pointer_cast<PVScalar>(pvValue);
-    }
-    if(!pvScalar) {
-        while(true) {
-             const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
-             if(fieldPtrArray.size()!=1) {
-                  throw std::logic_error(
-                      "PvaClientData::putString() pvRequest for multiple fields");
-             }
-             PVFieldPtr pvField(fieldPtrArray[0]);
-             Type type = pvField->getField()->getType();
-             if(type==scalar) {
-                 pvScalar = static_pointer_cast<PVScalar>(pvField);
-                 break;
-             }
-             if(pvField->getField()->getType()!=epics::pvData::structure) break;
-             pvStructure = static_pointer_cast<PVStructure>(pvField);
-        }
-    }
-    if(!pvScalar) {
-        throw std::logic_error(
-            "PvaClientData::putString() did not find a scalar field");
+    PVFieldPtr pvField = getSinglePVField();
+    Type type = pvField->getField()->getType();
+    if(type!=scalar) {
+        throw std::logic_error("PvaClientData::putString() did not find a scalar field");
     }
+    PVScalarPtr pvScalar = static_pointer_cast<PVScalar>(pvField);
     convert->fromString(pvScalar,value);
 }
 
 void PvaClientPutData::putDoubleArray(shared_vector<const double> const & value)
 {
     if(PvaClient::getDebug()) cout << "PvaClientPutData::putDoubleArray\n";
-    PVScalarArrayPtr pvScalarArray;
-    PVStructurePtr pvStructure = getPVStructure();
-    PVFieldPtr pvValue  = pvStructure->getSubField("value");
-    if(pvValue) {
-        Type type = pvValue->getField()->getType();
-        if(type==scalarArray) {
-             pvScalarArray = static_pointer_cast<PVScalarArray>(pvValue);
-        }
-    }
-    if(!pvScalarArray) {
-        while(true) {
-             const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
-             if(fieldPtrArray.size()!=1) {
-                  throw std::logic_error(
-                      "PvaClientData::putDoubleArray() pvRequest for multiple fields");
-             }
-             PVFieldPtr pvField(fieldPtrArray[0]);
-             Type type = pvField->getField()->getType();
-             if(type==scalarArray) {
-                 PVScalarArrayPtr pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
-                 break;
-             }
-             if(pvField->getField()->getType()!=epics::pvData::structure) break;
-             pvStructure = static_pointer_cast<PVStructure>(pvField);
-        }
-    }
-    if(!pvScalarArray) {
-        throw std::logic_error(
-            "PvaClientData::putDoubleArray() did not find a scalarArray field");
+    PVFieldPtr pvField = getSinglePVField();
+    Type type = pvField->getField()->getType();
+    if(type!=scalarArray) {
+        throw std::logic_error("PvaClientData::putDoubleArray() did not find a scalarArray field");
     }
+    PVScalarArrayPtr pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
     ScalarType scalarType = pvScalarArray->getScalarArray()->getElementType();
     if(!ScalarTypeFunc::isNumeric(scalarType)) {
         throw std::logic_error(
@@ -193,36 +125,12 @@ void PvaClientPutData::putDoubleArray(shared_vector<const double> const & value)
 void PvaClientPutData::putStringArray(shared_vector<const std::string> const & value)
 {
     if(PvaClient::getDebug()) cout << "PvaClientPutData::putStringArray\n";
-    PVScalarArrayPtr pvScalarArray;
-    PVStructurePtr pvStructure = getPVStructure();
-    PVFieldPtr pvValue  = pvStructure->getSubField("value");
-    if(pvValue) {
-       Type type = pvValue->getField()->getType();
-        if(type==scalarArray) {
-             pvScalarArray = static_pointer_cast<PVScalarArray>(pvValue);
-        }
-    }
-    if(!pvScalarArray) {
-        while(true) {
-             const PVFieldPtrArray fieldPtrArray(pvStructure->getPVFields());
-             if(fieldPtrArray.size()!=1) {
-                  throw std::logic_error(
-                      "PvaClientData::putStringArray() pvRequest for multiple fields");
-             }
-             PVFieldPtr pvField(fieldPtrArray[0]);
-             Type type = pvField->getField()->getType();
-             if(type==scalarArray) {
-                 pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
-                 break;
-             }
-             if(pvField->getField()->getType()!=epics::pvData::structure) break;
-             pvStructure = static_pointer_cast<PVStructure>(pvField);
-        }
-    }
-    if(!pvScalarArray) {
-        throw std::logic_error(
-            "PvaClientData::putStringArray() did not find a scalarArray field");
+    PVFieldPtr pvField = getSinglePVField();
+    Type type = pvField->getField()->getType();
+    if(type!=scalarArray) {
+        throw std::logic_error("PvaClientData::putStringArray() did not find a scalarArray field");
     }
+    PVScalarArrayPtr pvScalarArray = static_pointer_cast<PVScalarArray>(pvField);
     pvScalarArray->putFrom<const string>(value);
     return;
 }

src/pvaClientPutGet.cpp

@@ -55,7 +55,7 @@ public:
     {
         PvaClientPutGetPtr clientPutGet(pvaClientPutGet.lock());
         if(!clientPutGet) return;
-        clientPutGet->channelPutGetConnect(status,channelPutGet,putStructure,getStructure);  
+        clientPutGet->channelPutGetConnect(status,channelPutGet,putStructure,getStructure);
     }
 
     virtual void putGetDone(
@@ -173,7 +173,7 @@ void PvaClientPutGet::channelPutGetConnect(
            << " channelName " << pvaClientChannel->getChannel()->getChannelName()
            << " status.isOK " << (status.isOK() ? "true" : "false")
            << endl;
-    } 
+    }
     {
         Lock xx(mutex);
         this->channelPutGet = channelPutGet;
@@ -184,7 +184,7 @@ void PvaClientPutGet::channelPutGetConnect(
             pvaClientPutData->setMessagePrefix(channelPutGet->getChannel()->getChannelName());
             pvaClientGetData = PvaClientGetData::create(getStructure);
             pvaClientGetData->setMessagePrefix(channelPutGet->getChannel()->getChannelName());
-           
+
         } else {
              stringstream ss;
              ss << pvRequest;
@@ -199,7 +199,7 @@ void PvaClientPutGet::channelPutGetConnect(
           req->channelPutGetConnect(status,shared_from_this());
     }
     waitForConnect.signal();
-    
+
 }
 
 void PvaClientPutGet::putGetDone(
@@ -297,7 +297,7 @@ void PvaClientPutGet::connect()
     issueConnect();
     Status status = waitConnect();
     if(status.isOK()) return;
-    string message = string("channel ") 
+    string message = string("channel ")
         + pvaClientChannel->getChannel()->getChannelName()
         + " PvaClientPutGet::connect "
         + status.getMessage();
@@ -358,7 +358,7 @@ void PvaClientPutGet::putGet()
     issuePutGet();
     Status status = waitPutGet();
     if(status.isOK()) return;
-    string message = string("channel ") 
+    string message = string("channel ")
         + pvaClientChannel->getChannel()->getChannelName()
         + " PvaClientPut::putGet "
         + status.getMessage();
@@ -413,7 +413,7 @@ void PvaClientPutGet::getGet()
     issueGetGet();
     Status status = waitGetGet();
     if(status.isOK()) return;
-    string message = string("channel ") 
+    string message = string("channel ")
         + pvaClientChannel->getChannel()->getChannelName()
         + " PvaClientPut::getGet "
         + status.getMessage();
@@ -466,7 +466,7 @@ void PvaClientPutGet::getPut()
     issueGetPut();
     Status status = waitGetPut();
     if(status.isOK()) return;
-    string message = string("channel ") 
+    string message = string("channel ")
         + pvaClientChannel->getChannel()->getChannelName()
         + " PvaClientPut::getPut "
         + status.getMessage();

src/pvaClientRPC.cpp

@@ -94,7 +94,7 @@ PvaClientRPC::PvaClientRPC(
         PvaClientPtr const &pvaClient,
         Channel::shared_pointer const & channel,
         PVStructurePtr const &pvRequest)
-: 
+:
   connectState(connectIdle),
   pvaClient(pvaClient),
   channel(channel),
@@ -104,7 +104,7 @@ PvaClientRPC::PvaClientRPC(
 {
     if(PvaClient::getDebug()) {
          cout<< "PvaClientRPC::PvaClientRPC()"
-             << " channelName " << channel->getChannelName() 
+             << " channelName " << channel->getChannelName()
              << endl;
     }
 }
@@ -170,7 +170,7 @@ void PvaClientRPC::rpcConnect(
          cout << "PvaClientRPC::rpcConnect calling waitForConnect.signal\n";
     }
     waitForConnect.signal();
-    
+
 }
 
 void PvaClientRPC::requestDone(
@@ -195,7 +195,7 @@ void PvaClientRPC::requestDone(
              Channel::shared_pointer chan(channel.lock());
              if(chan) channelName = chan->getChannelName();
              string message = "channel "
-                 + channelName 
+                 + channelName
                  +" PvaClientRPC::requestDone"
                  + " but not active";
              throw std::runtime_error(message);
@@ -222,7 +222,7 @@ void PvaClientRPC::connect()
     Channel::shared_pointer chan(channel.lock());
     string channelName("disconnected");
     if(chan) channelName = chan->getChannelName();
-    string message = string("channel ") 
+    string message = string("channel ")
         + channelName
         + " PvaClientRPC::connect "
         + status.getMessage();
@@ -237,7 +237,7 @@ void PvaClientRPC::issueConnect()
         string channelName("disconnected");
         if(chan) channelName = chan->getChannelName();
         string message = string("channel ")
-            + channelName 
+            + channelName
             + " pvaClientRPC already connected ";
         throw std::runtime_error(message);
     }
@@ -326,7 +326,7 @@ void PvaClientRPC::request(
     PVStructure::shared_pointer const & pvArgument,
     PvaClientRPCRequesterPtr const & pvaClientRPCRequester)
 {
-    checkRPCState();   
+    checkRPCState();
     this->pvaClientRPCRequester = pvaClientRPCRequester;
     if(responseTimeout<=0.0) {
          {