Adds options.transformRequest to allow changing the structure of the request

readme.md

@@ -48,6 +48,7 @@ $(selector).autocomplete(options);
 | `onSearchStart` | `function (params) {}` called before Ajax request. `this` is bound to input element |
 | `onHint` | `function (hint) {}` used to change input value to first suggestion automatically |
 | `onSearchComplete` | `function (query, suggestions) {}` called after Ajax response is processed. `this` is bound to input element. `suggestions` is an array containing the results |
+| `transformRequest` | `function (query, options) {}` called before Ajax request. Use it if your `serviceUrl` expects the request in a strange format where the search term cannot be resolved as a property of the request |
 | `transformResult` | `function(response, originalQuery) {}` called after the result of the query is ready. Converts the result into response.suggestions format |
 | `onSelect` | `function (suggestion) {}` Callback function invoked when user selects suggestion from the list. `this` inside callback refers to input HtmlElement.|
 | `onSearchError` | `function (query, jqXHR, textStatus, errorThrown) {}` called if Ajax request fails. `this` is bound to input element |
@@ -218,7 +219,7 @@ supply just a string array for suggestions:
 ## Non standard query/results
 
 If your Ajax service expects the query in a different format, and returns data in a different format than the standard response,
-you can supply the "paramName" and "transformResult" options:
+you can supply the `paramName` and `transformResult` options:
 
 ```javascript
 $('#autocomplete').autocomplete({
@@ -233,6 +234,17 @@ $('#autocomplete').autocomplete({
 })
 ```
 
+If only changing the `paramName` isn't enough for the request to comply with the endpoint specifications,
+you can also use the `transformRequest` option to completely change the request structure:
+
+```javascript
+$('#autocomplete').autocomplete({
+    transformRequest: function(query, options) {
+        return JSON.stringify({ autocomplete: {term: query} })
+    }
+})
+```
+
 ## Grouping Results
 
 Specify `groupBy` option of you data property if you wish results to be displayed in groups. For example, set `groupBy: 'category'` if your suggestion data format is:

src/jquery.autocomplete.js

@@ -118,6 +118,7 @@
             preventBadQueries: true,
             lookupFilter: _lookupFilter,
             paramName: 'query',
+            transformRequest: _transformRequest,
             transformResult: _transformResult,
             showNoSuggestionNotice: false,
             noSuggestionNotice: 'No results',
@@ -129,6 +130,12 @@
         return suggestion.value.toLowerCase().indexOf(queryLowerCase) !== -1;
     };
 
+    function _transformRequest(query, options) {
+        var params = {};
+        params[options.paramName] = query;
+        return params;
+    };
+
     function _transformResult(response) {
         return typeof response === 'string' ? $.parseJSON(response) : response;
     };
@@ -546,7 +553,7 @@
                 cacheKey,
                 ajaxSettings;
 
-            options.params[options.paramName] = q;
+            options.params = options.transformRequest(q, options);
 
             if (options.onSearchStart.call(that.element, options.params) === false) {
                 return;