WP Ajax Query allows you to query your WordPress database using the same query paramaters you would use for WP_Query, and return a JSON respresentation of the query results. This allows developers to easily interface with WordPress without having to relearn a new API.
How It Works
The Ajax Query interface would be available at http://example.com/wp-admin/admin-ajax.php?action=query
A sample jQuery request would be like: $.get(ajaxurl, { action: ‘query’ }, function () { }, ‘json’);
Querying for a post: $.get(ajaxurl, { action: ‘query’, p: 1 }, function () { }, ‘json’);
JSON results: { “id”: 1, “type”: ‘post’, “title”: “Hello World”, “permalink”: “http:\/\/example.com\/?p=1” }
Query a category: $.get(ajaxurl, { action: ‘query’, cat: 1 }, function () { }, ‘json’);
JSON results: { “id”: 1 “type”: “category”, “permalink”: “http:\/\/example.com\/?cat=1”, “terms”: [], “posts”: [] }
terms and `posts` represents an array of either terms that are sub categories of the category, or posts belonging to the category.<h3>Why I Created It</h3>
Needed a common way to query the database for posts and taxonomies across multiple plugins, and didn’t find a suitable replacement.