Direct SVG rendering (#12157)

Introduce 'make svg' which calls a node script that compiles svg files
to `public/img/svg`. These files are vendored to not create a dependency
on Node for the backend build.

On the frontend side, configure webpack using `raw-loader` so SVGs can
be imported as string.

Also moved our existing SVGs to web_src/svg for consistency.

Fixes: https://github.com/go-gitea/gitea/issues/11618

modules/svg/discover_bindata.go

@@ -0,0 +1,32 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+// +build bindata
+
+package svg
+
+import (
+	"path"
+	"path/filepath"
+
+	"code.gitea.io/gitea/modules/public"
+)
+
+// Discover returns a map of discovered SVG icons in bindata
+func Discover() map[string]string {
+	svgs := make(map[string]string)
+
+	for _, file := range public.AssetNames() {
+		matched, _ := filepath.Match("img/svg/*.svg", file)
+		if matched {
+			content, err := public.Asset(file)
+			if err == nil {
+				filename := path.Base(file)
+				svgs[filename[:len(filename)-4]] = string(content)
+			}
+		}
+	}
+
+	return svgs
+}

modules/svg/discover_nobindata.go

@@ -0,0 +1,31 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+// +build !bindata
+
+package svg
+
+import (
+	"io/ioutil"
+	"path"
+	"path/filepath"
+
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// Discover returns a map of discovered SVG icons in the file system
+func Discover() map[string]string {
+	svgs := make(map[string]string)
+
+	files, _ := filepath.Glob(path.Join(setting.StaticRootPath, "public", "img", "svg", "*.svg"))
+	for _, file := range files {
+		content, err := ioutil.ReadFile(file)
+		if err == nil {
+			filename := path.Base(file)
+			svgs[filename[:len(filename)-4]] = string(content)
+		}
+	}
+
+	return svgs
+}

modules/svg/svg.go

@@ -0,0 +1,13 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package svg
+
+// SVGs contains discovered SVGs
+var SVGs map[string]string
+
+// Init discovers SVGs and populates the `SVGs` variable
+func Init() {
+	SVGs = Discover()
+}

modules/templates/helper.go

@@ -30,6 +30,7 @@ import (
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/svg"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/gitdiff"
@@ -439,9 +440,19 @@ func NewTextFuncMap() []texttmpl.FuncMap {
 	}}
 }
 
+var widthRe = regexp.MustCompile(`width="[0-9]+?"`)
+var heightRe = regexp.MustCompile(`height="[0-9]+?"`)
+
 // SVG render icons
 func SVG(icon string, size int) template.HTML {
-	return template.HTML(fmt.Sprintf(`<svg class="svg %s" width="%d" height="%d" aria-hidden="true"><use xlink:href="#%s" /></svg>`, icon, size, size, icon))
+	if svgStr, ok := svg.SVGs[icon]; ok {
+		if size != 16 {
+			svgStr = widthRe.ReplaceAllString(svgStr, fmt.Sprintf(`width="%d"`, size))
+			svgStr = heightRe.ReplaceAllString(svgStr, fmt.Sprintf(`height="%d"`, size))
+		}
+		return template.HTML(svgStr)
+	}
+	return template.HTML("")
 }
 
 // Safe render raw as HTML