Is it possible to use wp_localize_script to create global JS variables without a specific script handle?

Question

Can we somehow use wp_localize_script() to create global js variables without a specific script handle which can be accessed from all the js files, even if the js scripts are not enqueued properly by using wp_enqueue_script ?

This is the code I am using which creates varibale for 'ajaxscript' handle, so I cant access the object 'ajaxobject' in a js file which is being included in the header.php directly by <script src="xxx" .... />

wp_register_script( 'ajaxscript', get_bloginfo( 'template_url' ) . '/js/ajaxscript.js', array(), $version );
wp_enqueue_script( 'ajaxscript' );
wp_localize_script( 'ajaxscript', 'ajaxobject',
    array( 
        'ajaxurl'   => admin_url( 'admin-ajax.php' ),
        'ajaxnonce' => wp_create_nonce( 'itr_ajax_nonce' )
    )
);

Answer 1

Instead of using wp_localize_script in that case, you can hook your js variables at wp_head, that way it would be available to all js files like:

function my_js_variables(){ ?>
      <script type="text/javascript">
        var ajaxurl = '<?php echo admin_url( "admin-ajax.php" ); ?>';
        var ajaxnonce = '<?php echo wp_create_nonce( "itr_ajax_nonce" ); ?>';
      </script><?php
}
add_action ( 'wp_head', 'my_js_variables' )

Also to make it more error proof, it's advisable to use wp_json_encode() for the data.

add_action ( 'wp_head', 'my_js_variables' );
function my_js_variables(){ ?>
  <script type="text/javascript">
    var ajaxurl = <?php echo wp_json_encode( admin_url( "admin-ajax.php" ) ); ?>;      
    var ajaxnonce = <?php echo wp_json_encode( wp_create_nonce( "itr_ajax_nonce" ) ); ?>;
    var myarray = <?php echo wp_json_encode( 
       array( 
         'foo' => 'bar',
         'available' => TRUE,
         'ship' => array( 1, 2, 3, ),
       ) 
    ); ?>
  </script>
  <?php
 }

Answer 2

You can export any data you want in the wp_head hook, as the answers above show. However, you should use json_encode to prepare the PHP data for exporting to JS instead of trying to embed raw values into JS literals:

function my_js_variables(){
    ?>
    <script>
    var ajaxurl = <?php echo json_encode( admin_url( "admin-ajax.php" ) ) ?>;
    var ajaxnonce = <?php echo json_encode( wp_create_nonce( "itr_ajax_nonce" ) ) ?>;
    var myarray = <?php echo json_encode( array( 
        'food' => 'bard',
        'bard' => false,
        'quux' => array( 1, 2, 3, ),
    ) ) ?>;
    </script>
    <?php
}
add_action ( 'wp_head', 'my_js_variables' )

Using json_encode makes it easier on yourself, and it prevents accidental syntax errors if your string includes any quote marks. Even more importantly, using json_encode thwarts XSS attacks.

Answer 3

I ended up doing this. It works now !! Thanks @dot1

function itr_global_js_vars() {
    $ajax_url = 'var itrajaxobject = {"itrajaxurl":"'. admin_url( 'admin-ajax.php' ) .'", "itrajaxnonce":"'. wp_create_nonce( 'itr_ajax_nonce' ) .'"};';
    echo "<script type='text/javascript'>\n";
    echo "/* <![CDATA[ */\n";
    echo $ajax_url;
    echo "\n/* ]]> */\n";
    echo "</script>\n";
}
add_action( 'wp_head', 'itr_global_js_vars' );

Answer 4

While this isn't my finest work, this is another straight-forward way to accomplish putting data in the response:

<?php

/**
 * Add data to global context.
 *
 * @param string $name
 * @param mixed $value
 * @return mixed|array
 */
function global_js($name = null, $value = null)
{

    static $attached = false;
    static $variables = [];

    if (! $attached) {

        $provide = function () use (&$variables) {

            if (! empty($variables)) {

                echo("<script type=\"text/javascript\">\n\n");

                foreach ($variables as $name => $value) {

                    echo("    window['$name'] = JSON.parse('".json_encode($value)."');\n");
                    unset($variables[$name]);

                }

                echo("\n</script>\n");

            }

        };

        add_action('wp_print_scripts', $provide, 0);
        add_action('wp_print_footer_scripts', $provide, 0);

        $attached = true;

    }

    if (is_null($name) && is_null($value)) {
        return $variables;
    }

    return $variables[$name] = $value;

}

Add some JS data to the window context:

<?php

global_js('fruits', ['apple', 'peach']);

// produces: `window['fruits'] = JSON.parse('["apple", "peach"]');`

This will work for either the header scripts or footer scripts and won't repeat itself.