Exporting Custom Taxonomy in plugin

Question

I am writing a plugin which requires exporting custom taxonomies in csv on submit button click. I am using get_terms() to export taxonomies terms. I have written a class file which handle this operation and this file is included on the top of plugin main file.

I have searched about it and found out that get_terms() doesn't work until theme function.php is not loaded. So I want to know where should I include the class file. I have checked various hooks also but problem is that if I include it on admin_menu or admin_init hooks then it also outputs some other text of wordpress in exported csv file.

So please let me know how should I include the class file.

Answer 1

If you use admin_init no text should be output in the file unless you have some php notice.

Edit:

The following code should do.

<?php
/**
 * download_custom_taxonomy_csv_154304
 */
add_action('admin_init', 'download_custom_taxonomy_csv_154304');
function download_custom_taxonomy_csv_154304 () {

    // Check for GET request
    if ( isset( $_GET['download_ct_csv'] ) ){
        header('Content-type: text/csv');
        header('Content-disposition: attachment;filename=myct.csv');

        // Run here your code

        exit;
    }

}