Allow filtering of "Add New [Post Type]" URL on edit.php

[tbuteler]

I've recently attempted to use add_filter('admin_url','filter_function'), only to discover that there are many URLs in the admin area that are not passed through the admin_url() function. While there may be a good reason for that to happen, I figured it wouldn't hurt to check the possibility of changing one of them.

The one URL I haven't been able to find a workaround to is the "Add New [Post Type]" button on the edit.php screen, on top the post table, which also appears when editing an existing post. From what I gather, it is generated in the following file/line ​http://core.trac.wordpress.org/browser/trunk/wp-admin/edit.php#L189 for the first case, and on this one ​http://core.trac.wordpress.org/browser/trunk/wp-admin/edit-form-advanced.php#L198 for the second case.

Fixing this, assuming it's possible without compromising a functionality I'm not aware of, would be as simple as replacing this:

<a href="<?php echo $post_new_file ?>" ...

And this:

<a href="<?php echo esc_url( $post_new_file ) ?>" ...

With this:

<a href="<?php echo admin_url($post_new_file); ?>" ...

And this:

<a href="<?php echo esc_url( admin_url($post_new_file) ) ?>" ...

[scribu]

Sidenote: esc_url() is either necessary or it isn't, so one of the usages is incorrect.

Otherwise, using admin_url() there seems like a good idea.

[kawauso]

$post_new_file is set around ​http://core.trac.wordpress.org/browser/trunk/wp-admin/edit.php#L38, so assuming we trust the post type slug is valid since it's in get_post_types(), the esc_url() instance is the incorrect one.

[c3mdigital]

Refresh of original patch

[desrosj]

Patch worked fine for me. Was able to filter the link in both cases described.

[jeremyfelt]

Patch still applies cleanly in src. Would esc_url( admin_url() ) be overkill here?

[nacin]

+1 on the patch. esc_url() makes sense here — not for security concerns, but for the distinct possibility that the filtering of post-new.php would add an ampersand to it, and that should be encoded.

[helen]

In 25527:

Allow the "Add New" URL on post edit screens to be filtered via admin_url(). props SergeyBiryukov, jeremyfelt, c3mdigital. fixes #18504.