get current custom post ID by WP_Query method

Since the AJAX can be called from anywhere, even by a search engine, you should pass the ID manually. To do this, you need to include the ID of your current page somewhere in your template.

There is a common practice to include extra information in hidden input elements. You can add this hidden element to your template file:

<input id="my-post-id" type="hidden" value="<?php echo get_the_ID();?>">

Now, you can get the post’s ID in your AJAX call:

var theID;
theID = jQuery("#my-post-id").val();

This way, you can include this value in your call:

function customFunction() {
    var theID;
    theID = jQuery("#my-post-id").val();
    jQuery.ajax({
        type: 'GET', 
        url: 'AJAX URL HERE', 
        data: { postid: theID }, 
        // The rest of the AJAX here
    }
};

Now, you can check if the ID is set in your Admin-AJAX:

function get_blueprints_for_building () {
    // Stop execution if the function is called from out of the page
    if (!isset($_GET['postid'])) exit('Please set a post ID!');
    $id = $_GET['postid'];
    // Now we have the ID!
}

There you go.

Note!

I would also recommend that you use the REST API instead of Admin-AJAX. It’s easier and faster to set up. Take a look at my answer here.

UPDATE

Instead of creating a hidden input, you can also use wp_localize_script to pass your ID to the script. You need to have an enqueued script though.

wp_localize_script( 
    'my-js', // The ID of your enqueued JS file
    'my_localized_js', // The prefix for object
    $my_localized_array // The array that contains your data
);

Now, you can set the ID of the current page in your array:

$my_localized_array = array(
    'postID' => get_the_ID,
);

After doing this, you can access your ID in the JS file by using this:

var id = my_localized_js.postID;

Which can be used in the AJAX call later.

Note!

UPDATE

Related Posts: