Polymer elements added to third_party/polymer.

third_party/polymer/components/core-ajax/core-ajax.html

+<!--
+Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+
+<!--
+@group Polymer Core Elements
+
+The `core-ajax` element exposes `XMLHttpRequest` functionality.
+
+    <core-ajax
+        auto
+        url="http://gdata.youtube.com/feeds/api/videos/"
+        params='{"alt":"json", "q":"chrome"}'
+        handleAs="json"
+        on-core-response="{{handleResponse}}"></core-ajax>
+ 
+With `auto` set to `true`, the element performs a request whenever
+its `url` or `params` properties are changed.
+
+Note: The `params` attribute must be double quoted JSON.
+
+You can trigger a request explicitly by calling `go` on the
+element.
+
+@element core-ajax
+@status beta
+@homepage github.io
+-->
+<link rel="import" href="core-xhr.html">
+<polymer-element name="core-ajax" hidden attributes="url handleAs auto params response method headers body contentType withCredentials">
+<script>
+
+  Polymer('core-ajax', {
+    /**
+     * Fired when a response is received.
+     * 
+     * @event core-response
+     */
+
+    /**
+     * Fired when an error is received.
+     * 
+     * @event core-error
+     */
+
+    /**
+     * Fired whenever a response or an error is received.
+     *
+     * @event core-complete
+     */
+
+    /**
+     * The URL target of the request.
+     * 
+     * @attribute url
+     * @type string
+     * @default ''
+     */
+    url: '',
+
+    /**
+     * Specifies what data to store in the `response` property, and
+     * to deliver as `event.response` in `response` events.
+     * 
+     * One of:
+     * 
+     *    `text`: uses `XHR.responseText`.
+     *    
+     *    `xml`: uses `XHR.responseXML`.
+     *    
+     *    `json`: uses `XHR.responseText` parsed as JSON.
+     *
+     *    `arraybuffer`: uses `XHR.response`.
+     *
+     *    `blob`: uses `XHR.response`.
+     *
+     *    `document`: uses `XHR.response`.
+     *  
+     * @attribute handleAs
+     * @type string
+     * @default 'text'
+     */
+    handleAs: '',
+
+    /**
+     * If true, automatically performs an Ajax request when either `url` or `params` changes.
+     *
+     * @attribute auto
+     * @type boolean
+     * @default false
+     */
+    auto: false,
+
+    /**
+     * Parameters to send to the specified URL, as JSON.
+     *  
+     * @attribute params
+     * @type string (JSON)
+     * @default ''
+     */
+    params: '',
+
+    /**
+     * Returns the response object.
+     *
+     * @attribute response
+     * @type Object
+     * @default null
+     */
+    response: null,
+
+    /**
+     * The HTTP method to use such as 'GET', 'POST', 'PUT', or 'DELETE'.
+     * Default is 'GET'.
+     *
+     * @attribute method
+     * @type string
+     * @default ''
+     */
+    method: '',
+
+    /**
+     * HTTP request headers to send.
+     *
+     * Example:
+     *
+     *     <core-ajax 
+     *         auto
+     *         url="http://somesite.com"
+     *         headers='{"X-Requested-With": "XMLHttpRequest"}'
+     *         handleAs="json"
+     *         on-core-response="{{handleResponse}}"></core-ajax>
+     *  
+     * @attribute headers
+     * @type Object
+     * @default null
+     */
+    headers: null,
+
+    /**
+     * Optional raw body content to send when method === "POST".
+     *
+     * Example:
+     *
+     *     <core-ajax method="POST" auto url="http://somesite.com"
+     *         body='{"foo":1, "bar":2}'>
+     *     </core-ajax>
+     *  
+     * @attribute body
+     * @type Object
+     * @default null
+     */
+    body: null,
+
+    /**
+     * Content type to use when sending data.
+     *
+     * @attribute contentType
+     * @type string
+     * @default 'application/x-www-form-urlencoded'
+     */
+    contentType: 'application/x-www-form-urlencoded',
+
+    /**
+     * Set the withCredentials flag on the request.
+     * 
+     * @attribute withCredentials
+     * @type boolean
+     * @default false
+     */
+    withCredentials: false,
+    
+    /**
+     * Additional properties to send to core-xhr.
+     *
+     * Can be set to an object containing default properties
+     * to send as arguments to the `core-xhr.request()` method
+     * which implements the low-level communication.
+     * 
+     * @property xhrArgs
+     * @type Object
+     * @default null
+     */
+    xhrArgs: null,
+     
+    ready: function() {
+      this.xhr = document.createElement('core-xhr');
+    },
+
+    receive: function(response, xhr) {
+      if (this.isSuccess(xhr)) {
+        this.processResponse(xhr);
+      } else {
+        this.error(xhr);
+      }
+      this.complete(xhr);
+    },
+
+    isSuccess: function(xhr) {
+      var status = xhr.status || 0;
+      return !status || (status >= 200 && status < 300);
+    },
+
+    processResponse: function(xhr) {
+      var response = this.evalResponse(xhr);
+      this.response = response;
+      this.fire('core-response', {response: response, xhr: xhr});
+    },
+
+    error: function(xhr) {
+      var response = xhr.status + ': ' + xhr.responseText;
+      this.fire('core-error', {response: response, xhr: xhr});
+    },
+
+    complete: function(xhr) {
+      this.fire('core-complete', {response: xhr.status, xhr: xhr});
+    },
+
+    evalResponse: function(xhr) {
+      return this[(this.handleAs || 'text') + 'Handler'](xhr);
+    },
+
+    xmlHandler: function(xhr) {
+      return xhr.responseXML;
+    },
+
+    textHandler: function(xhr) {
+      return xhr.responseText;
+    },
+
+    jsonHandler: function(xhr) {
+      var r = xhr.responseText;
+      try {
+        return JSON.parse(r);
+      } catch (x) {
+        console.warn('core-ajax caught an exception trying to parse reponse as JSON:');
+        console.warn('url:', this.url);
+        console.warn(x);
+        return r;
+      }
+    },
+
+    documentHandler: function(xhr) {
+      return xhr.response;
+    },
+
+    blobHandler: function(xhr) {
+      return xhr.response;
+    },
+
+    arraybufferHandler: function(xhr) {
+      return xhr.response;
+    },
+
+    urlChanged: function() {
+      if (!this.handleAs) {
+        var ext = String(this.url).split('.').pop();
+        switch (ext) {
+          case 'json':
+            this.handleAs = 'json';
+            break;
+        }
+      }
+      this.autoGo();
+    },
+
+    paramsChanged: function() {
+      this.autoGo();
+    },
+
+    autoChanged: function() {
+      this.autoGo();
+    },
+
+    // TODO(sorvell): multiple side-effects could call autoGo 
+    // during one micro-task, use a job to have only one action 
+    // occur
+    autoGo: function() {
+      if (this.auto) {
+        this.goJob = this.job(this.goJob, this.go, 0);
+      }
+    },
+
+    /**
+     * Performs an Ajax request to the specified URL.
+     *
+     * @method go
+     */
+    go: function() {
+      var args = this.xhrArgs || {};
+      // TODO(sjmiles): we may want XHR to default to POST if body is set
+      args.body = this.body || args.body;
+      args.params = this.params || args.params;
+      if (args.params && typeof(args.params) == 'string') {
+        args.params = JSON.parse(args.params);
+      }
+      args.headers = this.headers || args.headers || {};
+      if (args.headers && typeof(args.headers) == 'string') {
+        args.headers = JSON.parse(args.headers);
+      }
+      if (this.contentType) {
+        args.headers['content-type'] = this.contentType;
+      }
+      if (this.handleAs === 'arraybuffer' || this.handleAs === 'blob' ||
+          this.handleAs === 'document') {
+        args.responseType = this.handleAs;
+      }
+      args.withCredentials = this.withCredentials;
+      args.callback = this.receive.bind(this);
+      args.url = this.url;
+      args.method = this.method;
+      return args.url && this.xhr.request(args);
+    }
+
+  });
+
+</script>
+</polymer-element>