Caption support (#2462)

Co-authored-by: WithoutPants <53250216+WithoutPants@users.noreply.github.com>

vendor/github.com/asticode/go-astikit/template.go

@@ -0,0 +1,156 @@
+package astikit
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"text/template"
+)
+
+// Templater represents an object capable of storing and parsing templates
+type Templater struct {
+	layouts   []string
+	m         sync.Mutex
+	templates map[string]*template.Template
+}
+
+// NewTemplater creates a new templater
+func NewTemplater() *Templater {
+	return &Templater{templates: make(map[string]*template.Template)}
+}
+
+// AddLayoutsFromDir walks through a dir and add files as layouts
+func (t *Templater) AddLayoutsFromDir(dirPath, ext string) (err error) {
+	// Get layouts
+	if err = filepath.Walk(dirPath, func(path string, info os.FileInfo, e error) (err error) {
+		// Check input error
+		if e != nil {
+			err = fmt.Errorf("astikit: walking layouts has an input error for path %s: %w", path, e)
+			return
+		}
+
+		// Only process files
+		if info.IsDir() {
+			return
+		}
+
+		// Check extension
+		if ext != "" && filepath.Ext(path) != ext {
+			return
+		}
+
+		// Read layout
+		var b []byte
+		if b, err = ioutil.ReadFile(path); err != nil {
+			err = fmt.Errorf("astikit: reading %s failed: %w", path, err)
+			return
+		}
+
+		// Add layout
+		t.AddLayout(string(b))
+		return
+	}); err != nil {
+		err = fmt.Errorf("astikit: walking layouts in %s failed: %w", dirPath, err)
+		return
+	}
+	return
+}
+
+// AddTemplatesFromDir walks through a dir and add files as templates
+func (t *Templater) AddTemplatesFromDir(dirPath, ext string) (err error) {
+	// Loop through templates
+	if err = filepath.Walk(dirPath, func(path string, info os.FileInfo, e error) (err error) {
+		// Check input error
+		if e != nil {
+			err = fmt.Errorf("astikit: walking templates has an input error for path %s: %w", path, e)
+			return
+		}
+
+		// Only process files
+		if info.IsDir() {
+			return
+		}
+
+		// Check extension
+		if ext != "" && filepath.Ext(path) != ext {
+			return
+		}
+
+		// Read file
+		var b []byte
+		if b, err = ioutil.ReadFile(path); err != nil {
+			err = fmt.Errorf("astikit: reading template content of %s failed: %w", path, err)
+			return
+		}
+
+		// Add template
+		// We use ToSlash to homogenize Windows path
+		if err = t.AddTemplate(filepath.ToSlash(strings.TrimPrefix(path, dirPath)), string(b)); err != nil {
+			err = fmt.Errorf("astikit: adding template failed: %w", err)
+			return
+		}
+		return
+	}); err != nil {
+		err = fmt.Errorf("astikit: walking templates in %s failed: %w", dirPath, err)
+		return
+	}
+	return
+}
+
+// AddLayout adds a new layout
+func (t *Templater) AddLayout(c string) {
+	t.layouts = append(t.layouts, c)
+}
+
+// AddTemplate adds a new template
+func (t *Templater) AddTemplate(path, content string) (err error) {
+	// Parse
+	var tpl *template.Template
+	if tpl, err = t.Parse(content); err != nil {
+		err = fmt.Errorf("astikit: parsing template for path %s failed: %w", path, err)
+		return
+	}
+
+	// Add template
+	t.m.Lock()
+	t.templates[path] = tpl
+	t.m.Unlock()
+	return
+}
+
+// DelTemplate deletes a template
+func (t *Templater) DelTemplate(path string) {
+	t.m.Lock()
+	defer t.m.Unlock()
+	delete(t.templates, path)
+}
+
+// Template retrieves a templates
+func (t *Templater) Template(path string) (tpl *template.Template, ok bool) {
+	t.m.Lock()
+	defer t.m.Unlock()
+	tpl, ok = t.templates[path]
+	return
+}
+
+// Parse parses the content of a template
+func (t *Templater) Parse(content string) (o *template.Template, err error) {
+	// Parse content
+	o = template.New("root")
+	if o, err = o.Parse(content); err != nil {
+		err = fmt.Errorf("astikit: parsing template content failed: %w", err)
+		return
+	}
+
+	// Parse layouts
+	for idx, l := range t.layouts {
+		if o, err = o.Parse(l); err != nil {
+			err = fmt.Errorf("astikit: parsing layout #%d failed: %w", idx+1, err)
+			return
+		}
+	}
+	return
+}