Make Advanced Custom Fields smarter about handling date fields

I love Advanced Custom Fields almost as much as I love WordPress itself. But that’s not to say it doesn’t have its problems. Most are obscure, and minor… and incredibly aggravating once you stumble upon them.

Here’s one such case. Date Picker fields are great, but no one seems to be able to agree on how to store dates in a database… other than insisting on avoiding Unix timestamps, the obvious choice.

ACF stores its dates, for some reason, in YYYYMMDD format (or, as we’d express it in PHP Land, Ymd). No delimiters at all. If you’re not going to use Unix timestamps, why not at least use the MySQL convention of Y-m-d H:i:s? But I digress.

I’m presently working on a project that merges some functionality of ACF and Gravity Forms, along with some custom code, to create a jobs board. It’s super-slick how Gravity Forms can create posts from a form submission, and even set them to pending review so a site editor can come in and review them before publishing.

But… dates. Jobs boards have a lot of dates. And while Gravity Forms offers a wealth of options for date string format, Ymd isn’t one of them. So it ends up storing the date value in the database in a format ACF doesn’t like. Because ACF is very picky. It wants that format, and no other. If the value in the field is not in Ymd format, the value displayed on the admin editing screen is just… blank. And then when you save, whatever was previously saved in that field is erased.

It doesn’t have to be this way. And thanks to the following bit of code, it won’t be. Now bear in mind, this is only altering what ACF renders on the editing screen. Once you’ve saved again from that point, the date will be stored in ACF’s preferred format, but up until then, it will be in whatever other format it was in when it landed in the database.

If you’re writing your front end code proactively, that won’t matter. Because you’re already assuming data inconsistency and using strtotime() to standardize any dates you’re working with in your templates, right? Of course you are.

OK, then. So the real goal here is just to get ACF to display the correct, saved date when you go in to edit the post, so it doesn’t then wipe out the date when you hit Save Changes.

In your functions.php file, or wherever you think is best (a plugin would be nice), do this:

function acf_smart_dates($field) {
  if ($field['value']) {
    $field['value'] = date('Ymd',strtotime($field['value']));
  }
  return $field;
}
add_filter('acf/prepare_field/type=date_picker','acf_smart_dates');

That’ll do.

How to REALLY check if the content is empty in WordPress

Problem: You want to check if the content in a WordPress post is empty. Seems easy, but do a Google search on the topic and you’ll see the question asked and — incorrectly — answered several times.

The fact is, I know how to do this. I was just hoping there was a built-in function in WordPress that I didn’t know about. Apparently not, so I wrote my own.

Why isn’t it easy and obvious how to check for the content being empty? Well, you could do this:

if ($post->post_content == '') { ... }

That will work. If the content is really empty. That means a zero-length string. As in strlen($post->post_content) == 0. Which it might be. But probably not.

If you’ve worked with real world site content, or even someone else’s Word documents before, you know that blank space is invisible, and a lot of times there’s a lot of blank space in a document that is not truly “empty.” Spaces, line breaks, HTML paragraphs with nothing but a non-breaking space in them. It all takes up space, and makes the content look empty, even when it’s not.

That last example is the critical one here. A WordPress post may look like it has no content, but if someone pressed Enter while the cursor was in the content box and then saved the page, it most likely has at least one <p>&nbsp;</p> in it.

So what you need is a function that takes all of that invisible cruft into account. Since it doesn’t seem like WordPress has such a function built in, I wrote my own, which I have made as compact as possible:

function empty_content($str) {
    return trim(str_replace('&nbsp;','',strip_tags($str))) == '';
}

This function takes the string you pass into it, strips out all HTML tags, then removes any non-breaking space entities, and then trims all whitespace. If there’s nothing but that stuff, then it becomes an empty string. If there’s any “real” content, the string won’t be empty. Then it just compares whatever it has left against an actual empty string, and returns the boolean result.

So now if you want to check if the WordPress content is really empty, you can do this:

if (empty_content($post->post_content)) { ... }

This will return true if the content is empty; false if it’s not.

Update (8/31/2017): This post continues to be one of the most frequently viewed on my blog, and I’ve been meaning for ages to amend it with this important note. As written here, you’ll get an erroneous true returned if the only content is in HTML, for instance, an image. If you want the function to return false if there’s no text content, then leave it as-is. But you can add a second input parameter to the strip_tags() function to tell it to leave certain HTML tags alone. If you want to allow image tags, for instance, the modified code would read as such:

function empty_content($str) {
    return trim(str_replace('&nbsp;','',strip_tags($str,'<img>'))) == '';
}

Yes, Virginia, there really is a difference between null and false

Fairly often, it’s necessary in PHP programming to write your code around the fact that, most of the time, PHP does not distinguish between null, false and 0, although there is, nonetheless, a distinction between all three.

Today I ran into one of the few instances where I was expecting PHP to treat them as equivalent, but it did not.

Often I am working with arrays, and I write conditionals that should only execute if there are elements in the array. Technically the proper check for the status of an array-type variable is the is_array() function, but most of the time I don’t use that. I may have initialized the array variable or not, but that’s irrelevant to me; what I care about is whether there’s anything in the array, so I just use count() instead.

These days I’m working on some object-oriented code, and I’ve been writing several “get” methods that return either an array of data or, as I had originally written them, a false value if no matching data exists.

Fine. But then I applied some of this new OO code to an existing page, and found that one of my count()-based conditionals was evaluating incorrectly. I checked the variable, whose value was set by one of the object methods, and as anticipated, its value was false. But strangely, the count() function was returning 1 rather than 0 when applied to the variable.

I resisted my initial temptation to switch from count() to is_array() because I don’t want to have to change every place where I use it. Then I tried changing the “failed” return value of the method from false to null and, what do you know, it worked!

So now I’ve gone through all of my various “get” methods and, on failure, they’re returning null instead of false.

T_PAAMAYIM_NEKUDOTAYIM

I am certainly accustomed to encountering PHP parser errors, but I was not expecting to see this: T_PAAMAYIM_NEKUDOTAYIM

And apparently I’m not alone. Even with an explanation (it’s Hebrew for “double colons”… and I leave for you to discover on your own why PHP constants might be named in transliterated Hebrew), it’s still a bit confusing, as the expected character should have been a dollar sign, not a double colon. Still awaiting an answer on that one…

A fix for a fix in WordPress 2.1

One thing that surprised me when I started using WordPress again is that its search function only searches on blog posts, not on static pages. I suppose if most WordPress sites are 99.9% blog posts, then it probably makes sense, but I have enough static pages on my site that I’d like to make searchable to warrant changing this.

Fortunately, someone has. Unfortunately this “Search Pages” plug-in is out of date and no longer works with current versions of WordPress. I dug in a bit and figured out why: the plug-in alters the SQL query that performs the search, but the substring it replaces in the query no longer exists! So I hunted down the place where the query occurs in the WordPress core, adjusted the plug-in as needed, and it works!

Here, then, is my hack of the Search Pages plug-in, modified to work with WordPress 2.1. (I’m not sure which other versions of WordPress it will or will not work with.)

[ search_pages.php.tar.gz ] [ search_pages.php.zip ]