mindbreeze-wordpress-search.php

<?php

/**
 * Get the page number from the query string
 * In production, get this value from WordPress
 * @return integer
 */
function getPage()
{
  // deafult page number
  $page = 1;

  if (isset($_GET['page']) && $pageAsInt = (int) $_GET['page']) {
    // valid number set in query string
    return $pageAsInt;
  }

  return $page;
}

/**
 * Get the user query from the query string
 * In production, get this value from WordPress
 * @return string
 */
function getQuery()
{
  if (isset($_GET['q']) && !empty($_GET['q'])) {
    return htmlentities($_GET['q']);
  } else {
    throw new Exception('Please provide a query via the "q" query string parameter');
  }
}

/**
 * Get the source from the query string
 * @return string
 */
function getSource()
{
  if (isset($_GET['source']) && in_array($_GET['source'], ['ksas'])) {
    return $_GET['source'];
  } else {
    return null;
  }

}

/**
 * Generate the POST body
 * @param  string  $query User query
 * @param  integer $page  Requested page of results
 * @param  integer $count Number of results to return
 * @return string  JSON encoded string
 */
function getPostBody($query, $page = 1, $count = 10, $source = null)
{
  // array of properties we want returned with each result (see below)
  $properties = [
    'title',
    'content',
    'Description',
    'url',
    'icon'
  ];

  // start constructing the body
  $body = [
    'content_sample_length' => 300,                         // how many characters the snippet should be
    'query' => ['unparsed' => $query],                      // user query
    'count' => $count,                                      // how many results to return
    'max_page_count' => 10,                                 // how many 'pages' worth of pagination information to return
    'alternatives_query_spelling_max_estimated_count' => 5, // how many spelling suggestings to return
    'properties' => getProperties($properties)
  ];


  if ($source) {
    $body['source_context']= [
      'constraints' => addConstraint($source)
    ];
  }


  // add pagination data if we're on page 2+
  if ($page > 1) {

    if (!isset($_SESSION['search_qeng'][$query])) {
      throw new Exception('Qeng variables not set. Cannot get page ' . $page . ' of results');
    }

    $body['result_pages'] = [
      // qeng IDs from previous request
      'qeng_ids' => $_SESSION['search_qeng'][$query],

      // generate the "current page" data based on the requested page and count.
      'pages' => [
        [
          'starts' => [($page - 1) * $count], // offset
          'counts' => [$count], // how many results to return
          'current_page' => true,
          'page_number' => $page // requested page number
          ]
        ]
    ];
  }

  // uncomment this print statement to see the POST body
  // print_r($body); die();

  return json_encode($body);
}

/**
 * Given a list of properties, transform them into
 * the format expected by Mindbreeze
 * @param  array $properties Array of property names
 * @return array Array of arrays
 */
function getProperties($properties)
{
  return array_map(function ($property) {
    return [
      'name' => $property,
      'formats' => ['HTML', 'VALUE']
    ];
  }, $properties);
}

/**
 * Limit which datasources are being queried
 * @param string $constraint Constraint (ksas)
 * @return array
 */
function addConstraint($constraint)
{
  // list of all datasources on KSAS index
  $datasources = [
    'Web:ksas',
  ];

  // list of the datasources that apply to certain constraints.
  $constraints = [
    'ksas' => ['Web:ksas']
  ];

  // datasources that will be queried
  $in = $constraints[$constraint];

  // datasources that will NOT be queried
  $out = array_diff($datasources, $in);

  return [
    'filter_base' => array_map(function ($datasource) {
      return createFilter('fqcategory', $datasource);
    }, array_values($in)),
    'filtered' => array_map(function ($datasource) {
      return createFilter('fqcategory', $datasource);
    }, array_values($out))
  ];
}

/**
 * Create boolean filter for datasource constraints
 * @param  string $label Filter label
 * @param  string $term  Value of filter
 * @return array  Filter array
 */
function createFilter($label, $term, $type = 'and')
{
  return [
    $type => [
      [
        'label' => $label,
        'quoted_term' => $term
      ]
    ]
  ];
}

/**
 * Clean up the results from Mindbreeze. Instead of having the
 * result properties numerically indexed, index the properties
 * by the property title for easier retrieval. Upone return,
 * cleaned up data can be found in $results->data
 * @param  array $results Array of results from Mindbreeze
 * @return array Array of cleaned up results
 */
function cleanResults($results)
{
  return array_map(function ($result) {

    $result->data = new \StdClass();

    foreach ($result->properties as $property) {
      $name = str_replace([':', '/'], '_', strtolower($property->id));
      $result->data->$name = $property->data[0];
    }

    unset($result->properties);

    return $result;

  }, $results);
}

function mindbreeze_query_vars_filter($vars) {
  $vars[] = 'q';
  $vars[] = 'page';
  return $vars;
}
add_filter( 'query_vars', 'mindbreeze_query_vars_filter' );

// FIRE UP THE SESSION!
session_start();

// this require is here to show where the session_start(); is initiated
require __DIR__ . '/assets/mindbreeze/vendor/autoload.php';

$page = getPage();
$query = getQuery();
$count = 10;
$source = getSource(); // this will help illustrate how to get results from just one datasource

// create HTTP client
$guzzle = new \GuzzleHttp\Client([
    'verify' => false,
]);

// send the POST request
$response = $guzzle->post('https://search.jh.edu:23440/api/v2/search', [
  'body' => getPostBody($query, $page, $count, $source),
  'headers' => ['Content-Type' => 'application/json']
]);

// handle the response
if ($response->getStatusCode() !== 200) {
  // if not 200, display some kind of error message
  throw new Exception('failed to get a response from Mindbreeze');
}

// get the body of the response
$body = json_decode((string) $response->getBody());

if (!isset($body->resultset->results)) {
  $_SESSION['search_qeng'] = null;
  throw new Exception('no results');
}

// there are results, let's display them.
$_SESSION['search_qeng'][$query] = $body->resultset->result_pages->qeng_ids;

// clean up the properties of each result
$results = cleanResults($body->resultset->results); ?>

<h1>Search Results: <?php echo $query; ?></h1>

<?php
// display each result
foreach($results as $result)
	{
	// print_r($result); die();
?>

  <p>
    <a href='<?php echo $result->data->url->value->str; ?>'><?php echo $result->data->title->html; ?></a>
    <br />
    <?php echo $result->data->description->value->str; ?>
    <br />
    <?php echo $result->data->url->value->str; ?>
  </p>

<hr>

<?php
	}

// I think I need to write the following as a php class to save
// this data as a static member. That way I can share the qeng_id
// across all sessions, instead of per session.

$paged = get_query_var('paged') ? get_query_var('paged') : 1;
$site_path = site_url('/search');

if ($body->resultset->prev_avail):
	$newPage = $paged - 1;

	// an associative array containing the query var and its value

	$params = array(
		'q' => $query,
		'page' => $newPage
	); ?>
    
    <p><a href="<?php echo add_query_arg($params, $site_path); ?>">PREV</a></p>

<?php
elseif ($body->resultset->next_avail):
	$newPage = $paged + 1;
	$params = array(
		'q' => $query,
		'page' => $newPage
	); ?>
  
  <p><a href="<?php echo add_query_arg($params, $site_path); ?>">NEXT</a></p>

<?php 
endif; ?>