GET (url) parameters for data arrays?

• jack1

• September 12, 2015 at 5:37 am

Hi there, loving this plugin. I’ve purchased a few add-ons and they’ve been worth every penny!

Ok, here’s my question:

I have followed these instructions and can now successfully make queries using parameters appended to the end of my urls.

However, so far I have been querying radio button fields meaning the custom fields only contain a single value. However, when trying to query checkbox fields (containing multiple values) it doesn’t return any results.

Here is a hypothetical example: I have a field named music-taste. Options include “hip hop”, “blues”, “punk”.

I want to be able to make a query using a parameter similar to this:

?music-taste=blues

However, currently this isn’t working. Like I say, I have got radio buttons working fine.

Any help much appreciated 🙂

• John Huebner

• September 12, 2015 at 5:51 am

This document will probably help you http://www.advancedcustomfields.com/resources/querying-relationship-fields/

Chackbox fields are stored as arrays similar to the way relationship fields are stored.

So your meta query would look something like this.

meta_query' => array(
  array(
    'key' => 'music-taste', // name of custom field
    'value' => '"' . $taste . '"', // matches exaclty "123", not just 123. This prevents a match for "1234"
    'compare' => 'LIKE'
  )
)

• jack1

• September 12, 2015 at 11:15 pm

Hi John, thanks for this, I didn’t know they were treated similar to a relationship. Here is my current functions.php code based on Elliot’s tutorial:

// array of filters (field key => field name)
$GLOBALS['my_query_filters'] = array( 
	'example_field'   => 'example1', 
	'example_field_two'  =>   'example2',
	//'music-taste' => 'music-taste' (this is what I'm trying to make work)
);

// action
add_action('pre_get_posts', 'my_pre_get_posts', 10, 1);

function my_pre_get_posts( $query ) {
	
	// bail early if is in admin
	if( is_admin() ) {
		return;
	}
	
	// get meta query
	$meta_query = $query->get('meta_query');

	// loop over filters
	foreach( $GLOBALS['my_query_filters'] as $key => $name ) {
		
		// continue if not found in url
		if( empty($_GET[ $name ]) ) {
			continue;
		}
		
		// get the value for this filter
		// eg: http://www.website.com/events?city=melbourne,sydney
		$value = explode(',', $_GET[ $name ]);
		
		// append meta query
    	$meta_query[] = array(
            'key'		=> $name,
            'value'		=> $value,
            'compare'	=> 'IN',
        );  
	} 
	// update meta query
	$query->set('meta_query', $meta_query);
}

I’m unsure of how to incorporate your suggested code, being as my working queries are ‘compare’ => ‘IN’, and my checkboxes need to be ‘compare’ => ‘LIKE’.

Many thanks!

• John Huebner

• September 14, 2015 at 10:06 pm

There are a couple of things here, the first is the LIKE part. Another is that you can have multiple values, so you need to add a separate meta query for and then because of the way you’re doing this you may need to use a nested query with a relationship set, for more info on nested meta queries https://make.wordpress.org/core/2014/10/20/update-on-query-improvements-in-4-1/

I’m pretty sure this is correct, but I haven’t tested it. This will only work with values that are stored as arrays, like checkboxes. If you have other types of values that can be submitted in the url then you’d need to do a switch on $name and construct each nested query to match the way the type of is stored.

  
  function my_pre_get_posts( $query ) {
  
  // bail early if is in admin
  if (is_admin()) {
    return;
  }
  // get meta query
  $meta_query = $query->get('meta_query');
  
  // loop over filters
  foreach ($GLOBALS['my_query_filters'] as $key => $name) {
    $nested_query = array();
    // continue if not found in url
    if( empty($_GET[ $name ]) ) {
      continue;
    }
    // get the value for this filter
    // eg: http://www.website.com/events?city=melbourne,sydney
    $values = explode(',', $_GET[ $name ]);
    $nested_query['relation'] = 'OR';
    foreach ($values as $value) {
      $sub_query = array(
        'key' => $name,
        'value' => '"'.$value.'"',
        'compare' => 'LIKE',
      );
    }
    $meta_query[] = $nested_query;
  } 
  // update meta query
  $query->set('meta_query', $meta_query);
}