Refactor parts of the NTP to split things into more managable chunks....

chrome/browser/resources/shared/js/i18n_template.js

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @fileoverview This is a simple template engine inspired by JsTemplates
+ * optimized for i18n.
+ *
+ * It currently supports two handlers:
+ *
+ *   * i18n-content which sets the textContent of the element
+ *
+ *     <span i18n-content="myContent"></span>
+ *     i18nTemplate.process(element, {'myContent': 'Content'});
+ *
+ *   * i18n-values is a list of attribute-value or property-value pairs.
+ *     Properties are prefixed with a '.' and can contain nested properties.
+ *
+ *     <span i18n-values="title:myTitle;.style.fontSize:fontSize"></span>
+ *     i18nTemplate.process(element, {
+ *       'myTitle': 'Title',
+ *       'fontSize': '13px'
+ *     });
+ */
+
+var i18nTemplate = (function() {
+  /**
+   * This provides the handlers for the templating engine. The key is used as
+   * the attribute name and the value is the function that gets called for every
+   * single node that has this attribute.
+   * @type {Object}
+   */
+  var handlers = {
+    /**
+     * This handler sets the textContent of the element.
+     */
+    'i18n-content': function(element, attributeValue, obj) {
+      element.textContent = obj[attributeValue];
+    },
+
+    /**
+     * This is used to set HTML attributes and DOM properties,. The syntax is:
+     *   attributename:key;
+     *   .domProperty:key;
+     *   .nested.dom.property:key
+     */
+    'i18n-values': function(element, attributeValue, obj) {
+      var parts = attributeValue.replace(/\s/g, '').split(/;/);
+      for (var j = 0; j < parts.length; j++) {
+        var a = parts[j].match(/^([^:]+):(.+)$/);
+        if (a) {
+          var propName = a[1];
+          var propExpr = a[2];
+
+          // Ignore missing properties
+          if (propExpr in obj) {
+            var value = obj[propExpr];
+            if (propName.charAt(0) == '.') {
+              var path = propName.slice(1).split('.');
+              var object = element;
+              while (object && path.length > 1) {
+                object = object[path.shift()];
+              }
+              if (object) {
+                object[path] = value;
+                // In case we set innerHTML (ignoring others) we need to
+                // recursively check the content
+                if (path == 'innerHTML') {
+                  process(element, obj);
+                }
+              }
+            } else {
+              element.setAttribute(propName, value);
+            }
+          } else {
+            console.warn('i18n-values: Missing value for "' + propExpr + '"');
+          }
+        }
+      }
+    }
+  };
+
+  var attributeNames = [];
+  for (var key in handlers) {
+    attributeNames.push(key);
+  }
+  var selector = '[' + attributeNames.join('],[') + ']';
+
+  /**
+   * Processes a DOM tree with the {@code obj} map.
+   */
+  function process(node, obj) {
+    var elements = node.querySelectorAll(selector);
+    for (var element, i = 0; element = elements[i]; i++) {
+      for (var j = 0; j < attributeNames.length; j++) {
+        var name = attributeNames[j];
+        var att = element.getAttribute(name);
+        if (att != null) {
+          handlers[name](element, att, obj);
+        }
+      }
+    }
+  }
+
+  return {
+    process: process
+  };
+})();