As soon as you begin working on an advanced plugin or an application in which you try to maintain some form of solid cohesion (or even an API), then you end finding that there’s a function you need that isn’t available in the Codex.
This isn’t unique to WordPress. Any programming language that has a rich API ultimately has a set of solid features that allow you to build upon them to write more power functions.
For me, I try to publish most of my helper functions here on the site. It makes things searchable, available, and even available for code review for the more critical readers 
.
Case in point: In a recent project, I needed to find the permalink by slug in WordPress and there wasn’t a function available to do exactly that, so here’s what I ended up doing.
Getting The Permalink By Slug
I’ll discussing the following function in more detail after the code snippet, but the short of it is this:
- Pass the function the slug of the post
- Optionally provide post type
- The function will return said permalink
/**
* Returns the permalink for a page based on the incoming slug.
*
* @param string $slug The slug of the page to which we're going to link.
* @return string The permalink of the page
* @since 1.0
*/
function example_get_permalink_by_slug( $slug, $post_type = '' ) {
// Initialize the permalink value
$permalink = null;
// Build the arguments for WP_Query
$args = array(
'name' => $slug,
'max_num_posts' => 1
);
// If the optional argument is set, add it to the arguments array
if( '' != $post_type ) {
$args = array_merge( $args, array( 'post_type' => $post_type ) );
} // end if
// Run the query (and reset it)
$query = new WP_Query( $args );
if( $query->have_posts() ) {
$query->the_post();
$permalink = get_permalink( get_the_ID() );
} // end if
wp_reset_postdata();
return $permalink;
} // end example_get_permalink_by_slug
The code comments should be provide as much information as you need, but in order to be as clear as possible, here’s how the function works:
- After receiving the slug and the optional post type, the function initializes the value that will eventually be returned as the permalink. Initializing it to null makes it easier for external functions to determine if the functioned returned a value or a not.
- Next, an array of arguments is created and merged with the post type if it’s been specified
- An instance of WP_Query is initialized and executed. If a result is found, the permalink is returned; otherwise, null is returned.
Simple enough, right?
From an external perspective, you could call this function like this:
if( null != ( $permalink = example_get_permalink_by_slug( 'my-example-slug' ) ) {
// Do work with $permalink
}
Or like this:
if( null != ( $permalink = example_get_permalink_by_slug( 'my-example-slug', 'article' ) ) {
// Do work with $permalink
}
And that’s all there is to it.
Is there a reason you opted not to clone get_page_by_title and change it to a slug? I would think a raw SQL statement would be faster since it’s not calling a full Query. You could then call get_permalink. get_page_by_title already takes a post_type argument even.
The above code came largely out of two things:
WP_Querymaps to SQL and will likely generate a more optimal query than I’d be able to doWP_Queryso it’s become habit.All that to say, I think what you’ve mentioned is still a good (and a fast) solution – just a different.
Wouldn’t using get_page_by_path() be enough in that case? For example: http://erikt.tumblr.com/post/278953342/get-a-wordpress-page-id-with-the-slug
Also I think that wp_reset_postadata() is sufficient enough, no need to call wp_reset_query()
wp_reset_postdata() is enough. That was a typo on my part so thanks for pointing it out - fixed that in the post above.
Also,
get_page_by_pathis just as useful, but I think that a case can be made for the context of the function in the application. That is,example_get_permalink_by_slug()is what happens to work in the project I'm working on; however, what you've provided works just as well - though it's clear that it's intended purpose is to get the page ID, rather than the slug.That said, it's definitely possible to use the ID from the slug from your function to grab the permalink.
Either way, thanks for sharing!
Hey,
Thanks for the fixture.
I’m not sure what do you mean by ‘. That is, example_get_permalink_by_slug() is what happens to work in the project I’m working on; however, what you’ve provided works just as well – though it’s clear that it’s intended purpose is to get the page ID, rather than the slug.’
Aren’t you doing the same above? Essentially I’d rather reduce the amount of DB calls and doing a separate query might be less optimized than something built in. I haven’t investigated or debugged the code so I’m not sure about that
Thank you ! Always nice to check out the tips you provide
All I meant was that when I was building the project and writing the function that needed to return the permalink given a slug, this was the function that I ended up writing.
Generally speaking, I agree with you – I’m a fan of using what’s built-in and I’m certainly not above refactoring my own code to use what’s more efficient, but I covered here why I used the approach I did.
If, in fact, using the native methods proved more efficient, then I’d be all for changing it.
Would be a fun experiment if i can find the time to do it
.
Wow… Right, I haven’t checked your replies above
Apart from what you’ve stated it’s also nice to be creative and write something on your own.
Thanks !