Custom feed parameters / Template overriding

Question

Am relatively new to Wordpress development and looking for the best way to customize the output for a specific javascript app that will be pulling in the content dynamically, by using a Wordpress plugin.

I can do most of what I need to do by overriding the feed template, allowing custom output by search term, tag, and category. However, getting an individual post for the feed (ie. using p= or page_id= query variables) doesn't seem to be an option by default.

What would be the best, cleanest way (ie. least amount of conflicts) to create the custom output post/page output? Simply add a new query_var filter and hook into parse_request, add new query vars for the feed somehow, or some other method to override the template for the content from within the plugin code?

Thanks!

Answer 1

Do I understand right that you need to pull information from WP in JavaScript code?

In that case it would be appropriate to use WP's Ajax handler. See AJAX in Plugins in Codex.

If native feeds are very close to what you need another option is to register custom feed with add_feed() and use it with customized template or one of native feed template with tweaks.

Answer 2

I have had no problem using all standard wp query parameters with feeds, and thus no problem with the p= single post option.

See http://test.icalevents.com/ical-feeds/ scroll down - there is an example of an individual post feed (in this case and event custom post type, but same principle applies) called "christmas in july" which extracts a single post for that feed.

Maybe you need to relook at your code and how you are doing it. In this example the plugin is allowing normal wp_query to operate plus some filters to the query.

Answer 3

Looks like this does the trick, using the template_redirect hook within the plugin:

function my_app_request() {
    global $wp_query;

    if ( array_key_exists('mycustomvar', $wp_query->query_vars ) )
    {
        include( dirname( __FILE__ ) . '/templates/content-single.php' );
        exit;
    }
}

add_action('template_redirect', 'my_app_request');

function my_query_vars($vars) {
    $vars[] = 'mycustomvar';
    return $vars;
}

add_filter('query_vars', 'my_query_vars');

And from within the content-single.php I can format how needed:

<?php
echo json_encode(array('title'=>get_the_title()));
// ...

Now any valid url can have mycustomvar=1 (or similar) tacked onto the url and voila, content loaded without having to manually parse p or page_id query vars. Seems cleaner than using a parse_request hook.

If there's a better/cleaner way to do the above please let me know!