[Resolved] Assigning a value to a View filter using a checkbox with less-than comparison

[Author]

Posts

[Joff]

I am trying to create a search filter on a view as a checkbox input type, using a "less-than" comparison function (<).

I want to use the checkbox to filter out results on a "distance" field, to show posts with a distance of less than 30, but I don't understand where I enter the value to compare against.

[Nigel]

Hi Joff

Checkbox filters are not envisaged to be used in such a way, they are intended to be used with Types checkbox fields (where the value is set on the field itself), not with numeric fields.

You could add the search filter as a textbox (where your users enter a "Maximum distance" value), or you could add a select dropdown where you have multiple values they could choose from that you enter manually when inserting the field (see screenshot where I am adding a max employees filter to a company search).

If you really wanted to use a checkbox, your only alternative is to use the Views API (specifically wpv_filter_query) to modify the query parameters for a search where you added a checkbox filter with the equals comparison and then used the API filter to change the query as required.

See https://toolset.com/documentation/programmer-reference/views-filters/#wpv_filter_query

[Joff]

Hi Nigel,

Ok, that makes sense thanks. For wpv_filter_query, would this replace the entire query or can I specifically add the checkbox functionality and let everything else stay as it is?

[Nigel]

Hi Joff

That depends on your coding skills.

I recommend you add the filter to your query and simply dump the $view_arguments to your debug log to see what the query currently looks like.

Set up your View with the checkbox filter and the equals comparison. That way it should still get rendered on the front end (though it is unlikely to work correctly for the moment).

Add the following to your functions.php file, editing the view id as required.

/**
 * Customise View query parameters
 */
add_filter( 'wpv_filter_query', 'custom_filter_query', 101, 3);
function custom_filter_query( $views_args, $view_settings, $view_id ){

	if ( 99 == $view_id ) {

		error_log(print_r($view_args, true));
	}
}

And if you haven't already, turn on the debug log by editing your wp-config.php file and change the line with WP_DEBUG like so:

define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);

That will create a debug.log file in your wp-content directory which you can examine in any text editor.

Now visit the page where you have added your View. As you apply filters you will see how the query arguments are modified in your error log. Here Views is effectively just a friendly wrapper for the native WordPress WP_Query class, and you can see what the options are for the arguments here: https://codex.wordpress.org/Class_Reference/WP_Query

If it were just this custom field it would be easy enough to set the conditions for the meta query parameters, but if you have several custom field filters then you will need to incorporate your custom query rather than replace it.

See how you get on and let me know if you get stuck on something specific.

[Joff]

Thanks Nigel, I'll give this a go. I'm familiar with WP hooks so this shouldn't be an issue. I'll keep the thread as unresolved for now until I've made an attempt on the task.

[Nigel]

Great, it sounds like you know what you are doing.

Keep me posted.

[Joff]

Hi Nigel,

Re. your first reply you mentioned a screenshot example for max employees, but I don't see that. Are you able to attach it please?

[Nigel]

Sorry I missed uploading that, doing so now...

[Joff]

Thanks. I wasn't seeing the comparison function field on mine for some reason, but now it's there all of a sudden!

[Nigel]

The comparison field you need to scroll down to see it (on my screenshot I changed the CSS so that the whole dialog is visible, so it is easy to miss).

You need anymore help..?

[Joff]

Hi Nigel,

I've now got a function hooking into wpv_filter_query and I can manipulate the arguments but I can't get a Views filter checkbox added to the Filter Editor in order to determine whether to apply my custom query.

If I add a checkbox to a non-Types field (I'm using ACF), the View outputs the checkbox as "Empty field values or incorrect field defined.". If I create a Types Post Field of type Checkbox, I can create a new filter based on it but nothing is output on the front end - I was expecting to see a checkbox that I could have appropriated as a flag for my custom query.

Any ideas?

[Joff]

Hi Nigel,

I think I was over-complicating a solution. I think the wpv_filter_query hook is the correct approach but I've been able to get the results I want from simply using JS to populate a hidden Views Filter textbox which is then searched on.

Thanks for your help!

[Nigel]

Hi Joff

I was just working on this at the moment. When I initially suggested using the Views API I was able to get the field to render a checkbox on the front end, but for the life of me I can't now find the combination of settings where I managed to do so and was about to abandon that approach to think of another solution.

So I'm glad you beat me to the punch. Thanks for letting me know.

[Joff]

Not to worry, I still think there would be mileage in having the ability to use checkboxes in this way with Views so maybe one to escalate to a potential feature in the future?

Thanks again for your time.