X-Git-Url: https://gerrit.akraino.org/r/gitweb?a=blobdiff_plain;f=src%2Ffoundation%2Fapi%2Frevel%2Ftemplate_engine.go;fp=src%2Ffoundation%2Fapi%2Frevel%2Ftemplate_engine.go;h=a62f5f212669725b13c37d08e8f48b4a6ee8af0d;hb=1d1ee6961c93781e1187d8c7faa868da6b2f01f4;hp=0000000000000000000000000000000000000000;hpb=56dd5e0f2164b37b40ac1daa188ccc618b4cbd19;p=iec.git

diff --git a/src/foundation/api/revel/template_engine.go b/src/foundation/api/revel/template_engine.go
new file mode 100644
index 0000000..a62f5f2
--- /dev/null
+++ b/src/foundation/api/revel/template_engine.go
@@ -0,0 +1,118 @@
+package revel
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"path/filepath"
+	"strings"
+)
+
+type TemplateEngine interface {
+	// prase template string and add template to the set.
+	ParseAndAdd(basePath *TemplateView) error
+
+	// returns Template corresponding to the given templateName, or nil
+	Lookup(templateName string) Template
+
+	// Fired by the template loader when events occur
+	Event(event Event, arg interface{})
+
+	// returns true if this engine should be used to parse the file specified in baseTemplate
+	Handles(templateView *TemplateView) bool
+
+	// returns the name of the engine
+	Name() string
+}
+
+// The template view information
+type TemplateView struct {
+	TemplateName string // The name of the view
+	FilePath     string // The file path (view relative)
+	BasePath     string // The file system base path
+	FileBytes    []byte // The file loaded
+	EngineType   string // The name of the engine used to render the view
+}
+
+var templateLoaderMap = map[string]func(loader *TemplateLoader) (TemplateEngine, error){}
+
+// Allow for templates to be registered during init but not initialized until application has been started
+func RegisterTemplateLoader(key string, loader func(loader *TemplateLoader) (TemplateEngine, error)) (err error) {
+	if _, found := templateLoaderMap[key]; found {
+		err = fmt.Errorf("Template loader %s already exists", key)
+	}
+	templateLog.Debug("Registered template engine loaded", "name", key)
+	templateLoaderMap[key] = loader
+	return
+}
+
+// Sets the template name from Config
+// Sets the template API methods for parsing and storing templates before rendering
+func (loader *TemplateLoader) CreateTemplateEngine(templateEngineName string) (TemplateEngine, error) {
+	if "" == templateEngineName {
+		templateEngineName = GO_TEMPLATE
+	}
+	factory := templateLoaderMap[templateEngineName]
+	if nil == factory {
+		fmt.Printf("registered factories %#v\n %s \n", templateLoaderMap, templateEngineName)
+		return nil, errors.New("Unknown template engine name - " + templateEngineName + ".")
+	}
+	templateEngine, err := factory(loader)
+	if nil != err {
+		return nil, errors.New("Failed to init template engine (" + templateEngineName + "), " + err.Error())
+	}
+
+	templateLog.Debug("CreateTemplateEngine: init templates", "name", templateEngineName)
+	return templateEngine, nil
+}
+
+// Passing in a comma delimited list of engine names to be used with this loader to parse the template files
+func (loader *TemplateLoader) initializeEngines(runtimeLoader *templateRuntime, templateEngineNameList string) (err *Error) {
+	// Walk through the template loader's paths and build up a template set.
+	if templateEngineNameList == "" {
+		templateEngineNameList = GO_TEMPLATE
+
+	}
+	runtimeLoader.templatesAndEngineList = []TemplateEngine{}
+	for _, engine := range strings.Split(templateEngineNameList, ",") {
+		engine := strings.TrimSpace(strings.ToLower(engine))
+
+		if templateLoader, err := loader.CreateTemplateEngine(engine); err != nil {
+			runtimeLoader.compileError = &Error{
+				Title:       "Panic (Template Loader)",
+				Description: err.Error(),
+			}
+			return runtimeLoader.compileError
+		} else {
+			// Always assign a default engine, switch it if it is specified in the config
+			runtimeLoader.templatesAndEngineList = append(runtimeLoader.templatesAndEngineList, templateLoader)
+		}
+	}
+	return
+}
+
+func EngineHandles(engine TemplateEngine, templateView *TemplateView) bool {
+	if line, _, e := bufio.NewReader(bytes.NewBuffer(templateView.FileBytes)).ReadLine(); e == nil && string(line[:3]) == "#! " {
+		// Extract the shebang and look at the rest of the line
+		// #! pong2
+		// #! go
+		templateType := strings.TrimSpace(string(line[2:]))
+		if engine.Name() == templateType {
+			// Advance the read file bytes so it does not include the shebang
+			templateView.FileBytes = templateView.FileBytes[len(line)+1:]
+			templateView.EngineType = templateType
+			return true
+		}
+	}
+	filename := filepath.Base(templateView.FilePath)
+	bits := strings.Split(filename, ".")
+	if len(bits) > 2 {
+		templateType := strings.TrimSpace(bits[len(bits)-2])
+		if engine.Name() == templateType {
+			templateView.EngineType = templateType
+			return true
+		}
+	}
+	return false
+}