feat($interpolate): string interpolation function

1 files changed, 82 insertions, 0 deletions

diff --git a/src/service/interpolate.js b/src/service/interpolate.js
new file mode 100644
index 00000000..03692824
--- /dev/null
+++ b/src/service/interpolate.js
@@ -0,0 +1,82 @@
+'use strict';
+
+function $InterpolateProvider(){
+  this.$get = ['$parse', function($parse){
+    return function(text, templateOnly) {
+      var bindings = parseBindings(text);
+      if (hasBindings(bindings) || !templateOnly) {
+        return compileBindTemplate(text);
+      }
+    };
+  }];
+}
+
+var bindTemplateCache = {};
+function compileBindTemplate(template){
+  var fn = bindTemplateCache[template];
+  if (!fn) {
+    var bindings = [];
+    forEach(parseBindings(template), function(text){
+      var exp = binding(text);
+      bindings.push(exp
+        ? function(scope, element) { return scope.$eval(exp); }
+        : function() { return text; });
+    });
+    bindTemplateCache[template] = fn = function(scope, element, prettyPrintJson) {
+      var parts = [],
+          hadOwnElement = scope.hasOwnProperty('$element'),
+          oldElement = scope.$element;
+
+      // TODO(misko): get rid of $element
+      scope.$element = element;
+      try {
+        for (var i = 0; i < bindings.length; i++) {
+          var value = bindings[i](scope, element);
+          if (isElement(value))
+            value = '';
+          else if (isObject(value))
+            value = toJson(value, prettyPrintJson);
+          parts.push(value);
+        }
+        return parts.join('');
+      } finally {
+        if (hadOwnElement) {
+          scope.$element = oldElement;
+        } else {
+          delete scope.$element;
+        }
+      }
+    };
+  }
+  return fn;
+}
+
+
+function parseBindings(string) {
+  var results = [];
+  var lastIndex = 0;
+  var index;
+  while((index = string.indexOf('{{', lastIndex)) > -1) {
+    if (lastIndex < index)
+      results.push(string.substr(lastIndex, index - lastIndex));
+    lastIndex = index;
+
+    index = string.indexOf('}}', index);
+    index = index < 0 ? string.length : index + 2;
+
+    results.push(string.substr(lastIndex, index - lastIndex));
+    lastIndex = index;
+  }
+  if (lastIndex != string.length)
+    results.push(string.substr(lastIndex, string.length - lastIndex));
+  return results.length === 0 ? [ string ] : results;
+}
+
+function binding(string) {
+  var binding = string.replace(/\n/gm, ' ').match(/^\{\{(.*)\}\}$/);
+  return binding ? binding[1] : null;
+}
+
+function hasBindings(bindings) {
+  return bindings.length > 1 || binding(bindings[0]) !== null;
+}