template_adapter_go.go

package revel

import (
	"html/template"
	"io"
	"log"
	"strings"
)

const GO_TEMPLATE = "go"


// Adapter for Go Templates.
type GoTemplate struct {
	*template.Template
	engine *GoEngine
	*TemplateView
}

// return a 'revel.Template' from Go's template.
func (gotmpl GoTemplate) Render(wr io.Writer, arg interface{}) error {
	return gotmpl.Execute(wr, arg)
}

type GoEngine struct {
	loader      *TemplateLoader
	templateSet *template.Template
	// TemplatesBylowerName is a map from lower case template name to the real template.
	templatesBylowerName map[string]*GoTemplate
	splitDelims          []string
	CaseInsensitiveMode bool
}

func (i *GoEngine) ConvertPath(path string) string {
	if i.CaseInsensitiveMode {
		return strings.ToLower(path)
	}
	return path
}

func (i *GoEngine) Handles(templateView *TemplateView) bool{
	return EngineHandles(i, templateView)
}

func (engine *GoEngine) ParseAndAdd(baseTemplate *TemplateView) error {
	// If alternate delimiters set for the project, change them for this set
	if engine.splitDelims != nil && baseTemplate.Location() == ViewsPath {
		engine.templateSet.Delims(engine.splitDelims[0], engine.splitDelims[1])
	} else {
		// Reset to default otherwise
		engine.templateSet.Delims("", "")
	}
	templateSource := string(baseTemplate.FileBytes)
	lowerTemplateName := engine.ConvertPath(baseTemplate.TemplateName)
	tpl, err := engine.templateSet.New(baseTemplate.TemplateName).Parse(templateSource)
	if nil != err {
		_, line, description := ParseTemplateError(err)
		return &Error{
			Title:       "Template Compilation Error",
			Path:        baseTemplate.TemplateName,
			Description: description,
			Line:        line,
			SourceLines: strings.Split(templateSource, "\n"),
		}
	}
	engine.templatesBylowerName[lowerTemplateName] = &GoTemplate{Template: tpl, engine: engine, TemplateView: baseTemplate}
	return nil
}

func (engine *GoEngine) Lookup(templateName string) Template {
	// Case-insensitive matching of template file name
	if tpl, found := engine.templatesBylowerName[engine.ConvertPath(templateName)]; found {
		return tpl
	}
	return nil
}
func (engine *GoEngine) Name() string {
	return GO_TEMPLATE
}
func (engine *GoEngine) Event(action int, i interface{}) {
	if action == TEMPLATE_REFRESH_REQUESTED {
		// At this point all the templates have been passed into the
		engine.templatesBylowerName = map[string]*GoTemplate{}
		engine.templateSet = template.New("__root__").Funcs(TemplateFuncs)
		// Check to see what should be used for case sensitivity
		engine.CaseInsensitiveMode = Config.StringDefault("go.template.path", "lower") != "case"
	}
}
func init() {
	RegisterTemplateLoader(GO_TEMPLATE, func(loader *TemplateLoader) (TemplateEngine, error) {
		// Set the template delimiters for the project if present, then split into left
		// and right delimiters around a space character

		TemplateDelims := Config.StringDefault("template.go.delimiters", "")
		var splitDelims []string
		if TemplateDelims != "" {
			splitDelims = strings.Split(TemplateDelims, " ")
			if len(splitDelims) != 2 {
				log.Fatalln("app.conf: Incorrect format for template.delimiters")
			}
		}

		return &GoEngine{
			loader:               loader,
			templateSet:          template.New("__root__").Funcs(TemplateFuncs),
			templatesBylowerName: map[string]*GoTemplate{},
			splitDelims:          splitDelims,
		}, nil
	})
}