determine whether content is of type Page or a Post and display accordingly

Question

I'm looking for a way to open every/any link to a blog post in a lightbox/modal globally and without having to any extra classes or rel attribute to the link element. I know I can access this info from within the page or post itself, but is there a way, through some sort of AJAX call I presume, to get this data before the request for the content is actually made so that when I do retrieve the response content, I can either just display it normally in the same browser tab (in the case of a Page) or trigger a lightbox and populate it with the content instead.

At first I was thinking about using regular expression matching on the link element's href and if it matched something looking like a blog post URL, open the lightbox. that seems pretty hacky tho and is definitely not bulletproof.

This is what I've got so far...

JavaScript:

$('a:not([href^="#"])[href]').click(function(e) {
    e.preventDefault();
    var $this = $(this);
    var lnk = $this.attr('href');

    var jqxhr = $.post("/wp-content/themes/mist-child/php/get-post-type.php", {url: lnk});
    jqxhr.done(function(data) {
        if(data === 'post') {
            $.prettyPhoto.open(lnk + '?iframe=true&width=80%&height=80%');
        }
    });
});

get-post-type.php (/wp-content/themes/CHILD_THEME/php/...)

<?php
    require_once(rtrim($_SERVER['DOCUMENT_ROOT'], '/') . '/wp-load.php');


    $url = $_POST['url'];

    $postid = url_to_postid($url);
    echo(get_post_type($postid));
?>

The part where Posts get opened in the lightbox is working. It's a little slow - I'm guessing that loading wp-load.php adds quite a bit of overhead. is there any way to add my PHP somewhere in functions.php and call that function (with arguments) via AJAX?

I know it needs some work, but as far as a prototype goes, am I moving in the right direction? Please feel free to shoot this full of as many holes as you can find.

Answer 1

Going with @milo's suggestion in the comments of the OP, I added a function to functions.php that rewrites URLs output by the API with a specific query string key/value when the post_type is post. This allows me to see this on the front end quite easily and take the appropriate action on the link depending on the absence/presence of said query string data. In this case, the frontend script finds all the elements "marked" as linking to posts (and not pages) and simply opens their href in a lightbox. SO much simpler than making several AJAX calls when the page is rendered to check the post_type for various links on the page.

functions.php

function append_query_string( $url, $post, $leavename=false ) {
    if ( $post->post_type == 'post' ) {
        $url = add_query_arg( 'blogLnk', '1', $url );
    }
    return $url;
}
add_filter( 'post_link', 'append_query_string', 10, 3 );

JavaScript

var blogLnks = [
    'a[hrf*="blogLnk=1"]',
    'a[rel="blogLnk"]'
];
var $blogLnks = $(blogLnks.join(','));
$blogLnks.click(function(e) {
    e.preventDefault();
    console.log('click - open me in lightbox');
    var $this = $(this);
    var qs = '?iframe=true&width=80%&height=90%';
    var lnk = $this.attr('href');

    $.prettyPhoto.open(lnk + qs);
});

Answer 2

The wordpress way solution is

 // put this in header.php
var ajax_url ="<?php echo admin_url('admin-ajax.php');?>"

// in js file
$('a:not([href^="#"])[href]').click(function(e) {
    e.preventDefault();
    var $this = $(this);
    var lnk = $this.attr('href');

    var jqxhr = $.post(ajax_url, {'action':'list_content', url: lnk});
    jqxhr.done(function(data) {
        if(data === 'post') {
            $.prettyPhoto.open(lnk + '?iframe=true&width=80%&height=80%');
        }
    });
});

// functions.php
add_action('wp_ajax_nopriv_list_content', 'list_content');
add_action('wp_ajax_list_content', 'list_content');

function list_content() {

    $url = $_POST['url'];

    $postid = url_to_postid($url);
    echo(get_post_type($postid));
    die();
}