Filtering & Search

The plugin includes a set of helper functions for building custom filter and search interfaces using template functions.

How Filtering Works

Filtering is done through URL query parameters. When a page loads with ?workplace=oslo, the job feed is automatically limited to jobs where the workplace field contains “Oslo”.

The plugin provides helper functions to build filter URLs, count matches, and check active state.

Free-Text Search

Add a simple search form that searches across all job data:

<form method="get">
    <label for="jobSearch">Search</label>
    <input
        type="text"
        value="<?php echo $_GET['jobSearch'] ?? ''; ?>"
        name="jobSearch"
        id="jobSearch"
    />
    <button type="submit">Search</button>
</form>

get_jobpost_filters()

Returns a list of all distinct values for a given field across all job posts. Use this to build filter options.

Syntax

get_jobpost_filters( $field, $reduce_by_filter );

Parameter	Type	Required	Description
$field	string	Yes	The field name
$reduce_by_filter	bool	No	If true, only returns values matching the current filter. Default: false

Example

<?php
$locations = get_jobpost_filters('workplace');

if ($locations):
    echo "<h3>Locations</h3><ul>";
    foreach ($locations as $location):
        $url = get_jobpost_filter_url('workplace', $location);
        echo "<li><a href='$url'>$location</a></li>";
    endforeach;
    echo "</ul>";
endif;
?>

get_jobpost_filter_url()

Generates a URL that toggles a filter on or off. If the filter is already active, the URL removes it.

Syntax

get_jobpost_filter_url( $field, $value );

Parameter	Type	Required	Description
$field	string	Yes	The field name to filter
$value	string	Yes	The value to filter by

Example

<?php
$url = get_jobpost_filter_url('workplace', 'Oslo');
echo "<a href='$url'>Oslo</a>";
?>

Tip

If the feed is already filtered with workplace=oslo, the same link will remove this filter — it acts as a toggle.

get_jobpost_filter_count()

Returns the number of jobs matching a specific filter value.

Syntax

get_jobpost_filter_count( $field, $value );

Example

<?php
$url = get_jobpost_filter_url('workplace', 'Oslo');
$count = get_jobpost_filter_count('workplace', 'Oslo');
echo "<a href='$url'>Oslo ($count)</a>";
?>

has_jobpost_filter()

Check if a filter is currently active.

Syntax

has_jobpost_filter( $field, $value );

Parameter	Type	Required	Description
$field	string	Yes	The field name
$value	string	No	If set, checks if this specific value is active

Complete Filter Function

Here’s a reusable function that combines all the filter helpers:

<?php
function jobPostFilter(string $field, string $title, bool $reduce = false) {
    $items = get_jobpost_filters($field, $reduce);

    if (empty($items)) return;

    echo "<h3>$title</h3>";
    echo "<ul>";

    foreach ($items as $item) {
        $url = get_jobpost_filter_url($field, $item);
        $count = get_jobpost_filter_count($field, $item);
        $active = has_jobpost_filter($field, $item) ? 'active' : '';

        echo "<li class='$active'>";
        echo "<a href='$url' rel='nofollow'>$item ($count)</a>";
        echo "</li>";
    }

    echo "</ul>";
}
?>

<aside>
    <div class="job-filter">
        <?php jobPostFilter('workplace', 'Location', true); ?>
    </div>
    <div class="job-filter">
        <?php jobPostFilter('type', 'Job Type', true); ?>
    </div>
</aside>

Converting to a Custom Shortcode

You can register the filter function as a shortcode in your theme’s functions.php or via a code snippets plugin:

<?php
function jobPostFilter(string $field, string $title, bool $reduce = false) {
    $items = get_jobpost_filters($field, $reduce);
    $html = '';

    if (empty($items)) return $html;

    $html .= "<h3>$title</h3>";
    $html .= "<ul>";

    foreach ($items as $item) {
        $url = get_jobpost_filter_url($field, $item);
        $count = get_jobpost_filter_count($field, $item);
        $active = has_jobpost_filter($field, $item) ? 'active' : '';

        $html .= "<li class='$active'>";
        $html .= "<a href='$url' rel='nofollow'>$item ($count)</a>";
        $html .= "</li>";
    }

    $html .= "</ul>";
    return $html;
}

add_shortcode('job_filter', function ($params = []) {
    if (!function_exists('have_jobposts')) return '';

    $params = array_change_key_case((array) $params, CASE_LOWER);
    $options = shortcode_atts([
        'field' => 'type',
        'title' => 'Job type',
        'reduce' => '1'
    ], $params);

    return jobPostFilter(
        (string) $options['field'],
        (string) $options['title'],
        (bool) $options['reduce']
    );
});

// Usage: [job_filter field="workplace" title="Location" reduce="1"]

Caution

When adding filters, add nofollow to filter links and add your job listing path to robots.txt to prevent search engines from crawling the large number of filter URL combinations:

Disallow: /jobs/*