[MAJOR] Remove .ajax and allow async function for .setChoices

README.md

@@ -863,7 +863,9 @@ choices.disable();
 
 **Input types affected:** `select-one`, `select-multiple`
 
-**Usage:** Set choices of select input via an array of objects, a value name and a label name. This behaves the same as passing items via the `choices` option but can be called after initialising Choices. This can also be used to add groups of choices (see example 2); Optionally pass a true `replaceChoices` value to remove any existing choices. Optionally pass a `customProperties` object to add additional data to your choices (useful when searching/filtering etc). Passing an empty array as the first parameter, and a true `replaceChoices` is the same as calling `clearChoices` (see below).
+**Usage:** Set choices of select input via an array of objects (or function that returns array of object or promise of it), a value field name and a label field name.
+
+This behaves the similar as passing items via the `choices` option but can be called after initialising Choices. This can also be used to add groups of choices (see example 3); Optionally pass a true `replaceChoices` value to remove any existing choices. Optionally pass a `customProperties` object to add additional data to your choices (useful when searching/filtering etc). Passing an empty array as the first parameter, and a true `replaceChoices` is the same as calling `clearChoices` (see below).
 
 **Example 1:**
 
@@ -887,6 +889,22 @@ example.setChoices(
 ```js
 const example = new Choices(element);
 
+// Passing a function that returns Promise of choices
+example.setChoices(async () => {
+  try {
+    const items = await fetch('/items');
+    return items.json();
+  } catch (err) {
+    console.error(err);
+  }
+});
+```
+
+**Example 3:**
+
+```js
+const example = new Choices(element);
+
 example.setChoices(
   [
     {
@@ -1009,49 +1027,6 @@ example.setChoiceByValue('Two'); // Choice with value of 'Two' has now been sele
 
 **Usage:** Enables input to accept new values/select further choices.
 
-### ajax(fn);
-
-**Input types affected:** `select-one`, `select-multiple`
-
-**Usage:** Populate choices/groups via a callback.
-
-**Example:**
-
-```js
-var example = new Choices(element);
-
-example.ajax(function(callback) {
-  fetch(url)
-    .then(function(response) {
-      response.json().then(function(data) {
-        callback(data, 'value', 'label');
-      });
-    })
-    .catch(function(error) {
-      console.log(error);
-    });
-});
-```
-
-**Example 2:**
-If your structure differs from `data.value` and `data.key` structure you can write your own `key` and `value` into the `callback` function. This could be useful when you don't want to transform the given response.
-
-```js
-const example = new Choices(element);
-
-example.ajax(function(callback) {
-  fetch(url)
-    .then(function(response) {
-      response.json().then(function(data) {
-        callback(data, 'data.key', 'data.value');
-      });
-    })
-    .catch(function(error) {
-      console.log(error);
-    });
-});
-```
-
 ## Browser compatibility
 
 Choices is compiled using [Babel](https://babeljs.io/) to enable support for [ES5 browsers](http://caniuse.com/#feat=es5). If you need to support a browser that does not support one of the features listed below, I suggest including a polyfill from the very good [polyfill.io](https://cdn.polyfill.io/v2/docs/):

public/index.html

@@ -320,7 +320,7 @@ <h2>Single select input</h2>
         </select>
 
         <label for="choices-single-remove-xhr"
-          >Options from remote source (XHR) &amp; remove button</label
+          >Options from remote source (Fetch API) &amp; remove button</label
         >
         <select
           class="form-control"
@@ -627,17 +627,17 @@ <h2>Form interaction</h2>
           placeholder: true,
           placeholderValue: 'Pick an Strokes record',
           maxItemCount: 5,
-        }).ajax(function(callback) {
-          fetch(
+        }).setChoices(function() {
+          return fetch(
             'https://api.discogs.com/artists/55980/releases?token=QBRmstCkwXEvCjTclCpumbtNwvVkEzGAdELXyRyW',
           )
             .then(function(response) {
-              response.json().then(function(data) {
-                callback(data.releases, 'title', 'title');
-              });
+              return response.json();
             })
-            .catch(function(error) {
-              console.error(error);
+            .then(function(data) {
+              return data.releases.map(function(release) {
+                return { value: release.title, label: release.title };
+              });
             });
         });
 
@@ -685,46 +685,39 @@ <h2>Form interaction</h2>
 
         var singleFetch = new Choices('#choices-single-remote-fetch', {
           searchPlaceholderValue: 'Search for an Arctic Monkeys record',
-        }).ajax(function(callback) {
-          fetch(
-            'https://api.discogs.com/artists/391170/releases?token=QBRmstCkwXEvCjTclCpumbtNwvVkEzGAdELXyRyW',
-          )
-            .then(function(response) {
-              response.json().then(function(data) {
-                callback(data.releases, 'title', 'title');
-                singleFetch.setChoiceByValue('Fake Tales Of San Francisco');
+        })
+          .setChoices(function() {
+            return fetch(
+              'https://api.discogs.com/artists/391170/releases?token=QBRmstCkwXEvCjTclCpumbtNwvVkEzGAdELXyRyW',
+            )
+              .then(function(response) {
+                return response.json();
+              })
+              .then(function(data) {
+                return data.releases.map(function(release) {
+                  return { label: release.title, value: release.title };
+                });
               });
-            })
-            .catch(function(error) {
-              console.error(error);
-            });
-        });
+          })
+          .then(function(instance) {
+            instance.setChoiceByValue('Fake Tales Of San Francisco');
+          });
 
         var singleXhrRemove = new Choices('#choices-single-remove-xhr', {
           removeItemButton: true,
           searchPlaceholderValue: "Search for a Smiths' record",
-        }).ajax(function(callback) {
-          var request = new XMLHttpRequest();
-          request.open(
-            'get',
+        }).setChoices(function(callback) {
+          return fetch(
             'https://api.discogs.com/artists/83080/releases?token=QBRmstCkwXEvCjTclCpumbtNwvVkEzGAdELXyRyW',
-            true,
-          );
-          request.onreadystatechange = function() {
-            var status;
-            var data;
-            if (request.readyState === 4) {
-              status = request.status;
-              if (status === 200) {
-                data = JSON.parse(request.responseText);
-                callback(data.releases, 'title', 'title');
-                singleXhrRemove.setChoiceByValue('How Soon Is Now?');
-              } else {
-                console.error(status);
-              }
-            }
-          };
-          request.send();
+          )
+            .then(function(res) {
+              return res.json();
+            })
+            .then(function(data) {
+              return data.releases.map(function(release) {
+                return { label: release.title, value: release.title };
+              });
+            });
         });
 
         var genericExamples = new Choices('[data-trigger]', {