fixed #7, javascript filter for pongo2 with context in this variable

helper/template_filters.go

@@ -1,12 +1,21 @@
 package helper
 
 import (
+	"io/ioutil"
+	"path"
+	"strings"
+
 	"github.com/flosch/pongo2"
 	_ "github.com/flosch/pongo2-addons"
+	"github.com/robertkrimen/otto"
+	_ "github.com/robertkrimen/otto/underscore"
 )
 
 func init() {
-	pongo2.ReplaceFilter("markdown", MarkdownFilter)
+	err := pongo2.ReplaceFilter("markdown", MarkdownFilter)
+	if err != nil {
+		panic(err)
+	}
 }
 
 // MarkdownFilter is a pongo2 filter, which converts markdown to html
@@ -19,3 +28,59 @@ func MarkdownFilter(in *pongo2.Value, param *pongo2.Value) (*pongo2.Value, *pong
 				))),
 		nil
 }
+
+func RegisterFilters(dir string) {
+	files, err := ioutil.ReadDir(dir)
+	if err != nil {
+		Log.Panicf("could not read from template filters dir '%s': %s", dir, err)
+	}
+	for _, f := range files {
+		if !f.IsDir() {
+			switch path.Ext(f.Name()) {
+			case ".js":
+				jsFile := dir + "/" + f.Name()
+				Log.Debugf("trying to register filter from: %s", jsFile)
+				jsStr, err := ioutil.ReadFile(jsFile)
+				if err != nil {
+					Log.Panicf("could not read '%s': %s", jsFile, err)
+				}
+				vm := otto.New()
+				fn, err := vm.Run(jsStr)
+				if err != nil {
+					Log.Panicf("error in javascript vm for '%s': %s", jsFile, err)
+				}
+				if !fn.IsFunction() {
+					Log.Panicf("%s does not contain a function code", jsFile)
+				}
+
+				err = pongo2.RegisterFilter(
+					strings.TrimSuffix(f.Name(), ".js"),
+					func(in, param *pongo2.Value) (out *pongo2.Value, erro *pongo2.Error) {
+						thisObj, _ := vm.Object("({})")
+						if currentContext != nil {
+							thisObj.Set("context", *currentContext)
+						}
+
+						if err != nil {
+							Log.Panicf("could not set context as in '%s': %s", jsFile, err)
+						}
+						ret, err := fn.Call(thisObj.Value(), in.Interface(), param.Interface())
+						if err != nil {
+							Log.Panicf("error in javascript file '%s' while calling returned function: %s", jsFile, err)
+						}
+						retGo, err := ret.Export()
+						if err != nil {
+							Log.Panicf("export error for '%s': %s", jsFile, err)
+						}
+						return pongo2.AsValue(retGo), nil
+					},
+				)
+				if err != nil {
+					Log.Panicf("could not register filter from '%s': %s", jsFile, err)
+				}
+
+			}
+		}
+	}
+
+}