Frontend custom post submission results in wp_insert_post() undefined - ajax

Question

I've been struggling for a few days with this issue and I really hope you can help me out.
I've created a plugin, which is located in:
'/wp-content/plugins/my-cool-plugin'.
My plugin allows users to post a custom post type via a form on a public page, basically anyone should be able to post something.
Using jQuery, I listen to when my frontend form is submitted and using Ajax I pass the data from the form to a php file to process it into a post.
This file is located at:
'/wp-content/plugins/my-cool-plugin/inc/processor.php'.
Below is the content of my processor file:
$var1= $_POST['some'];
$var2= $_POST['data'];
$new_post = array(
'post_type' => 'my_custom_post',
'post_status' => 'publish',
'mcp_1' => $var1,
'mcp_2' => $var2
);
$post_id = wp_insert_post( $new_post, $wp_error );
if ($wp_error == 'false'){
$post_url = get_permalink( $post_id );
echo $post_url;
}else {
// some sort of error
}
When I test my form, it results in the following error:
Call to undefined function wp_insert_post() on line ... which is the following line:
$post_id = wp_insert_post( $new_post, $wp_error );
Do I need to include something since I'm not in the WordPress 'scope' anymore?
Or is there another (much better) way for inserting custom posts from a front end form?

Answer 1

Why are you running the file out of wordpress scope? That is not the best practive. Instead you could run it in wordpress scope and user wordpress native ajax.
add_action('wp_ajax_yourplugin_create_post', 'yourplugin_create_post');
add_action('wp_ajax_nopriv_yourplugin_create_post', 'yourplugin_create_post');
function yourplugin_create_post() {
// your code here
}
Then you would need your ajax url to be passed from php to js:
function your_plugin_ajaxurl() {
?>
<script type="text/javascript">
var yourPluginAjaxUrl = "<?php echo admin_url('admin-ajax.php'); ?>";
</script>
<?php
}
add_action('wp_head','your_plugin_ajaxurl');
Then you can use your ajax request but you would need to indicate action:yourplugin_create_post and url = yourPluginAjaxUrl

Answer 2

Try adding
require(dirname(__FILE__) . '/wp-load.php');

Answer 3

It took me some time to process Nick's answer, but I finally got it to work! Like Nick said, I dropped using the process file because is was out of the scope of WordPress. I moved my post creation from my proces file to a new function in the plugin init file (my-cool-plugin.php), as Nick suggested. This resulted in the following new function:
add_action('wp_ajax_coolplugin_create_post', 'coolplugin_create_post');
add_action('wp_ajax_nopriv_coolplugin_create_post', 'coolplugin_create_post');
function coolplugin_create_post() {
$var1 = $_POST['some'];
$var2 = $_POST['data'];
$new_post = array(
'post_type' => 'my_custom_post',
'post_status' => 'publish'
'post_title' => 'Some title'
);
$post_id = wp_insert_post( $new_post, $wp_error );
// check if there is a post id and use it to add custom meta
if ($post_id) {
update_post_meta($post_id, 'mcp_1', $var1);
update_post_meta($post_id, 'mcp_2', $var2);
}
if ($wp_error == false){
$post_url = get_permalink( $post_id );
echo $post_url;
}else {
// some sort of error
}
}
I also had to change the way I inserted my custom values into the newly created post, because the wp_insert_post() function only accepts default post parameters (see the wp_insert_post documentation for these parameters).
Next to my insert/create post function I also had to make some adjustments to my javascript file, which retrieves the filled in data from my form. Therefore (as Nick suggested) I needed to pass my Ajax URL from PHP to JS by adding the following function to my-cool-plugin.php like this:
function your_plugin_ajaxurl() { ?>
<script type="text/javascript">
var coolPluginAjaxUrl = "<?php echo admin_url('admin-ajax.php'); ?>";
</script>
<?php }
add_action('wp_head','your_plugin_ajaxurl');
By adding the coolPluginAjaxUrl variable to the head I'm able to use the URL in my javascript to post the data to when my form is submitted, like this:
$( '#form' ).on( 'submit', function(e) {
var request;
e.preventDefault();
var val_one = $( '#val-one' ).val();
var val_two = $( '#val-two' ).val();
var formData = {
action: 'coolplugin_create_post',
some: val_one,
data: val_two,
};
request = $.ajax({
type: 'POST',
url: coolPluginAjaxUrl,
data: formData,
});
});
The formData holds the coolplugin_create_post action defined in PHP and the request is posted to the coolPluginAjaxUrl URL, defined in the head.
Thanks Nick for pointing me into the right direction and I hope that my solution will also help others. Please note that I've stripped my code of several security measures for others to easily understand how the code works.