-
Promise polyfill is now a dev dependency and no longer shipped with
iron-ajax
.iron-ajax
uses thePromise
API, which is not yet supported in all browsers.The 1.x version of
iron-ajax
automatically loaded the promise polyfill. This forced the application to include the polyfill, whether or not it was needed.When using
iron-ajax
2.x with Polymer 1.x, you must provide your own Promise polyfill, if needed. For example, you could use the promise polyfill by installing it in your project:bower install --save PolymerLabs/promise-polyfill#1 - 2
Then your app should include the promise polyfill before loading
iron-ajax
:<link rel="import" href="bower_components/promise-polyfill/promise-polyfill-lite.html">
You can use a different promise polyfill if you need a more fully-featured implementation of Promise.
For Polymer 2.x, you do not need to provide your own Promise polyfill if you are using the web components polyfills. Because the web components v1 APIs depend on
Promise
, a promise polyfill is loaded when needed by the v1 polyfills (web-components-lite.js
orwebcomponents-loader.js
). -
New optional error information.
The
generateRequest
method returns aniron-request
element representing the request, and the request element provides acompletes
property, which is a promise that completes when the request either succeeds or fails.This version includes a new flag,
rejectWithRequest
, that modifies the error handling of thecompletes
promise. By default, when the promise is rejected (because the request failed), the rejection callback only receives anError
object describing the failure.With
rejectWithRequest
set to true, the callback receives an object with two keys,error
, the error message, andrequest
, the original request that the error is related to:let request = ironAjaxElement.generateRequest(); request.completes.then(function(req) { // succesful request, argument is iron-request element ... }, function(rejected) { // failed request, argument is an object let req = rejected.request; let error = rejected.error; ... } )
Because this change could break existing code,
rejectWithRequest
is false by default, however, in the next major release, this option will be removed and the new behavior made the default.
The iron-ajax
element exposes network request functionality.
<iron-ajax
auto
url="https://www.googleapis.com/youtube/v3/search"
params='{"part":"snippet", "q":"polymer", "key": "YOUTUBE_API_KEY", "type": "video"}'
handle-as="json"
on-response="handleResponse"
debounce-duration="300"></iron-ajax>
With auto
set to true
, the element performs a request whenever
its url
, params
or body
properties are changed. Automatically generated
requests will be debounced in the case that multiple attributes are changed
sequentially.
Note: The params
attribute must be double quoted JSON.
You can trigger a request explicitly by calling generateRequest
on the
element.
iron-request can be used to perform XMLHttpRequests.
<iron-request id="xhr"></iron-request>
...
this.$.xhr.send({url: url, body: params});