Ajax call not working in wordpress through a plugin-CodePudding

I have 2 Ajax call the first is working but when it send the data to other the file send_data.php and when I try to run any wordpress function it doesn't work!

This's the first ajax call ok now the data sent to send_data.php file when I try to run any wordpress function like this add_post_meta(2, 'dropbox', 'Senddataphp', false); it prints this error what I want to do is pretty simple just get the data from ajax insert into wp database but I've no idea everytime I work with js with php problems like this happens

caught Error: Call to undefined function add_post_meta() in C:\xampp\htdocs\wordpress\wp-content\plugins\Dropboxapi\includes\send_data.php:17
        Stack trace:

First Ajax code

$.ajax({
        
                type: "POST",
                url: 'wp-content/plugins/Dropboxapi/includes/send_data.php',
                data: {
                    req: JSON.stringify(dropbox_links)
                },
        
                cache: false,
                success: function(responseData) {
                    // consider using console.log for these kind of things.
                    console.log("Data recived: "   responseData);
                    console.log("First Ajax"   dropbox_links);
        
        
        
                }
            });

Second Ajax code here I tried to execute a function that take the sent data and insert into database but it doesn't work, dropbox.php file is the main file of the plugin

$.ajax({
            type: "POST",
            url: 'wp-content/plugins/Dropboxapi/dropbox.php',

            data: {
                functionname: 'printdata2'
            },

            success: function(obj, textstatus) {
                if (!('error' in obj)) {
                    var yourVariable = obj.result;
                    console.log("SEc Ajax"   dropbox_links   yourVariable);

                } else {
                    console.log(obj.error);
                    console.log("SEc1 errr Ajax"   dropbox_links  
                        yourVariable);
                }
            },
            error: function(msg) {
                console.log(
                    " errrnot sure what to ask for here to check issue"  
                    msg);
            }
        });

CodePudding user response：

When using ajax in WordPress the file that stores the function you want to run is not called directly. Instead admin-ajax.php is called, and callback function is added in 'action'. First create a function and add your add_meta_box inside it, then add wp_ajax action hooks like the following. Remember that every function which is going to be called by ajax request must end with wp_die().

function printdata2() {
  add_post_meta(2, 'dropbox', 'Senddataphp',  false);
  wp_die();
}
add_action( 'wp_ajax_nopriv_printdata2', 'printdata2' );
add_action( 'wp_ajax_printdata2', 'printdata2' );

Next use wp_localize_script() to pass admin_url('admin-ajax.php') to javascript.

function load_script() {
  wp_enqueue_script( 'your-js', get_template_directory_uri() . '/js/your-js.js', array('jquery') );
  wp_localize_script( 'your-js', 'ajax_object', array('ajaxurl' => admin_url('admin-ajax.php')) );
}
add_action('wp_enqueue_scripts', 'load_script');

Now in your javascript file call ajaxurl in url and the callback function name in action.

$.ajax({
  url: ajax_object.ajaxurl,
  data: {
    action: 'printdata2'
  },
  success: function(obj, textstatus) {
    // obj goes here...
  },
  error: function(msg) {
    console.log(msg);
  }
});