How can I write a Promise where the response is coming from an iron-ajax.
<iron-ajax id="listItems" method="GET" content-type="application/json" handle-as="json" last-response="{{items}}" on-error="handleErrorResponse"></iron-ajax>
this.data = {
get: function(sort, page, pageSize) {
return new Promise(function(resolve, reject) {
// Execute iron-ajax.
//...
// resolve(iron-ajax's response);
});
}
}
};You're looking for listItem.generateRequest(), since that returns iron-ajax's accompanying iron-request object, which in turn provides a promise, named request.completes.
https://www.webcomponents.org/element/PolymerElements/iron-ajax/iron-ajax#method-generateRequest
https://www.webcomponents.org/element/PolymerElements/iron-ajax/iron-request#property-completes
I modified your code sample below:
<iron-ajax id="listItems" method="GET" content-type="application/json" handle-as="json" last-response="{{items}}" on-error="handleErrorResponse"></iron-ajax>
this.data = {
get: function(sort, page, pageSize) {
return this.$.listItems.generateRequest().completes;
}
}
};Inspired by the more complex example at https://stackoverflow.com/a/37995462/2795627. Kudos to @akivajgordon.