class PagerDefault in Drupal 7

Query extender for pager queries.

This is the "default" pager mechanism. It creates a paged query with a fixed number of entries per page.

Hierarchy

class \SelectQueryExtender implements SelectQueryInterface
- class \PagerDefault

Expanded class hierarchy of PagerDefault

11 string references to 'PagerDefault'

blog_page_last in modules/blog/blog.pages.inc: Menu callback; displays a Drupal page containing recent blog entries of all users.
blog_page_user in modules/blog/blog.pages.inc: Menu callback; displays a Drupal page containing recent blog entries of a given user.
comment_get_thread in modules/comment/comment.module: Retrieve comments for a thread.
DatabaseSelectPagerDefaultTestCase::testHavingPagerQuery in modules/simpletest/tests/database_test.test: Confirm that a paging query with a having expression returns valid results.
DatabaseSelectPagerDefaultTestCase::testInnerPagerQuery in modules/simpletest/tests/database_test.test: Confirm that a pager query with inner pager query returns valid results.

... See full list

File

includes/pager.inc, line 15: Functions to aid in presenting database results as a set of pages.

View source

class PagerDefault extends SelectQueryExtender {

  /**
   * The highest element we've autogenerated so far.
   *
   * @var int
   */
  static $maxElement = 0;

  /**
   * The number of elements per page to allow.
   *
   * @var int
   */
  protected $limit = 10;

  /**
   * The unique ID of this pager on this page.
   *
   * @var int
   */
  protected $element = NULL;

  /**
   * The count query that will be used for this pager.
   *
   * @var SelectQueryInterface
   */
  protected $customCountQuery = FALSE;
  public function __construct(SelectQueryInterface $query, DatabaseConnection $connection) {
    parent::__construct($query, $connection);

    // Add pager tag. Do this here to ensure that it is always added before
    // preExecute() is called.
    $this
      ->addTag('pager');
  }

  /**
   * Override the execute method.
   *
   * Before we run the query, we need to add pager-based range() instructions
   * to it.
   */
  public function execute() {

    // Add convenience tag to mark that this is an extended query. We have to
    // do this in the constructor to ensure that it is set before preExecute()
    // gets called.
    if (!$this
      ->preExecute($this)) {
      return NULL;
    }

    // A NULL limit is the "kill switch" for pager queries.
    if (empty($this->limit)) {
      return;
    }
    $this
      ->ensureElement();
    $total_items = $this
      ->getCountQuery()
      ->execute()
      ->fetchField();
    $current_page = pager_default_initialize($total_items, $this->limit, $this->element);
    $this
      ->range($current_page * $this->limit, $this->limit);

    // Now that we've added our pager-based range instructions, run the query normally.
    return $this->query
      ->execute();
  }

  /**
   * Ensure that there is an element associated with this query.
   * If an element was not specified previously, then the value of the
   * $maxElement counter is taken, after which the counter is incremented.
   *
   * After running this method, access $this->element to get the element for this
   * query.
   */
  protected function ensureElement() {
    if (!isset($this->element)) {
      $this->element = self::$maxElement++;
    }
  }

  /**
   * Specify the count query object to use for this pager.
   *
   * You will rarely need to specify a count query directly.  If not specified,
   * one is generated off of the pager query itself.
   *
   * @param SelectQueryInterface $query
   *   The count query object.  It must return a single row with a single column,
   *   which is the total number of records.
   */
  public function setCountQuery(SelectQueryInterface $query) {
    $this->customCountQuery = $query;
  }

  /**
   * Retrieve the count query for this pager.
   *
   * The count query may be specified manually or, by default, taken from the
   * query we are extending.
   *
   * @return SelectQueryInterface
   *   A count query object.
   */
  public function getCountQuery() {
    if ($this->customCountQuery) {
      return $this->customCountQuery;
    }
    else {
      return $this->query
        ->countQuery();
    }
  }

  /**
   * Specify the maximum number of elements per page for this query.
   *
   * The default if not specified is 10 items per page.
   *
   * @param $limit
   *   An integer specifying the number of elements per page.  If passed a false
   *   value (FALSE, 0, NULL), the pager is disabled.
   */
  public function limit($limit = 10) {
    $this->limit = $limit;
    return $this;
  }

  /**
   * Specify the element ID for this pager query.
   *
   * The element is used to differentiate different pager queries on the same
   * page so that they may be operated independently.  If you do not specify an
   * element, every pager query on the page will get a unique element.  If for
   * whatever reason you want to explicitly define an element for a given query,
   * you may do so here.
   *
   * Setting the element here also increments the static $maxElement counter,
   * which is used for determining the $element when there's none specified.
   *
   * Note that no collision detection is done when setting an element ID
   * explicitly, so it is possible for two pagers to end up using the same ID
   * if both are set explicitly.
   *
   * @param $element
   */
  public function element($element) {
    $this->element = $element;
    if ($element >= self::$maxElement) {
      self::$maxElement = $element + 1;
    }
    return $this;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
PagerDefault::$customCountQuery	protected	property	The count query that will be used for this pager.
PagerDefault::$element	protected	property	The unique ID of this pager on this page.
PagerDefault::$limit	protected	property	The number of elements per page to allow.
PagerDefault::$maxElement	static	property	The highest element we've autogenerated so far.
PagerDefault::element	public	function	Specify the element ID for this pager query.
PagerDefault::ensureElement	protected	function	Ensure that there is an element associated with this query. If an element was not specified previously, then the value of the $maxElement counter is taken, after which the counter is incremented.
PagerDefault::execute	public	function	Override the execute method. Overrides SelectQueryExtender::execute
PagerDefault::getCountQuery	public	function	Retrieve the count query for this pager.
PagerDefault::limit	public	function	Specify the maximum number of elements per page for this query.
PagerDefault::setCountQuery	public	function	Specify the count query object to use for this pager.
PagerDefault::__construct	public	function	Overrides SelectQueryExtender::__construct
SelectQueryExtender::$connection	protected	property	The connection object on which to run this query.
SelectQueryExtender::$placeholder	protected	property	The placeholder counter.
SelectQueryExtender::$query	protected	property	The SelectQuery object we are extending/decorating.
SelectQueryExtender::$uniqueIdentifier	protected	property	A unique identifier for this query object.
SelectQueryExtender::addExpression	public	function	Adds an expression to the list of "fields" to be SELECTed. Overrides SelectQueryInterface::addExpression
SelectQueryExtender::addField	public	function	Adds a field to the list to be SELECTed. Overrides SelectQueryInterface::addField
SelectQueryExtender::addJoin	public	function	Join against another table in the database. Overrides SelectQueryInterface::addJoin
SelectQueryExtender::addMetaData	public	function	Adds additional metadata to the query. Overrides QueryAlterableInterface::addMetaData
SelectQueryExtender::addTag	public	function	Adds a tag to a query. Overrides QueryAlterableInterface::addTag
SelectQueryExtender::arguments	public	function	Gets a complete list of all values to insert into the prepared statement. Overrides QueryConditionInterface::arguments
SelectQueryExtender::compile	public	function	Compiles the saved conditions for later retrieval. Overrides QueryConditionInterface::compile
SelectQueryExtender::compiled	public	function	Check whether a condition has been previously compiled. Overrides QueryConditionInterface::compiled
SelectQueryExtender::condition	public	function	Helper function: builds the most common conditional clauses. Overrides QueryConditionInterface::condition
SelectQueryExtender::conditions	public	function	Gets a complete list of all conditions in this conditional clause. Overrides QueryConditionInterface::conditions
SelectQueryExtender::countQuery	public	function	Get the equivalent COUNT query of this query as a new query object. Overrides SelectQueryInterface::countQuery	1
SelectQueryExtender::distinct	public	function	Sets this query to be DISTINCT. Overrides SelectQueryInterface::distinct
SelectQueryExtender::exists	public	function	Sets a condition that the specified subquery returns values. Overrides QueryConditionInterface::exists
SelectQueryExtender::extend	public	function	Enhance this object by wrapping it in an extender object. Overrides QueryExtendableInterface::extend
SelectQueryExtender::fields	public	function	Add multiple fields from the same table to be SELECTed. Overrides SelectQueryInterface::fields
SelectQueryExtender::forUpdate	public	function	Add FOR UPDATE to the query. Overrides SelectQueryInterface::forUpdate
SelectQueryExtender::getArguments	public	function	Compiles and returns an associative array of the arguments for this prepared statement. Overrides SelectQueryInterface::getArguments
SelectQueryExtender::getExpressions	public	function	Returns a reference to the expressions array for this query. Overrides SelectQueryInterface::getExpressions
SelectQueryExtender::getFields	public	function	Returns a reference to the fields array for this query. Overrides SelectQueryInterface::getFields
SelectQueryExtender::getGroupBy	public	function	Returns a reference to the group-by array for this query. Overrides SelectQueryInterface::getGroupBy
SelectQueryExtender::getMetaData	public	function	Retrieves a given piece of metadata. Overrides QueryAlterableInterface::getMetaData
SelectQueryExtender::getOrderBy	public	function	Returns a reference to the order by array for this query. Overrides SelectQueryInterface::getOrderBy
SelectQueryExtender::getTables	public	function	Returns a reference to the tables array for this query. Overrides SelectQueryInterface::getTables
SelectQueryExtender::getUnion	public	function	Returns a reference to the union queries for this query. This include queries for UNION, UNION ALL, and UNION DISTINCT. Overrides SelectQueryInterface::getUnion
SelectQueryExtender::groupBy	public	function	Groups the result set by the specified field. Overrides SelectQueryInterface::groupBy
SelectQueryExtender::hasAllTags	public	function	Determines if a given query has all specified tags. Overrides QueryAlterableInterface::hasAllTags
SelectQueryExtender::hasAnyTag	public	function	Determines if a given query has any specified tag. Overrides QueryAlterableInterface::hasAnyTag
SelectQueryExtender::hasTag	public	function	Determines if a given query has a given tag. Overrides QueryAlterableInterface::hasTag
SelectQueryExtender::having	public	function
SelectQueryExtender::havingArguments	public	function
SelectQueryExtender::havingCompile	public	function
SelectQueryExtender::havingCondition	public	function	Helper function to build most common HAVING conditional clauses. Overrides SelectQueryInterface::havingCondition
SelectQueryExtender::havingConditions	public	function
SelectQueryExtender::innerJoin	public	function	Inner Join against another table in the database. Overrides SelectQueryInterface::innerJoin
SelectQueryExtender::isNotNull		function	Sets a condition that the specified field be NOT NULL. Overrides QueryConditionInterface::isNotNull
SelectQueryExtender::isNull		function	Sets a condition that the specified field be NULL. Overrides QueryConditionInterface::isNull
SelectQueryExtender::isPrepared	public	function	Indicates if preExecute() has already been called on that object. Overrides SelectQueryInterface::isPrepared
SelectQueryExtender::join	public	function	Default Join against another table in the database. Overrides SelectQueryInterface::join
SelectQueryExtender::leftJoin	public	function	Left Outer Join against another table in the database. Overrides SelectQueryInterface::leftJoin
SelectQueryExtender::nextPlaceholder	public	function	Implements QueryPlaceholderInterface::nextPlaceholder(). Overrides QueryPlaceholderInterface::nextPlaceholder
SelectQueryExtender::notExists	public	function	Sets a condition that the specified subquery returns no values. Overrides QueryConditionInterface::notExists
SelectQueryExtender::orderBy	public	function	Orders the result set by a given field. Overrides SelectQueryInterface::orderBy
SelectQueryExtender::orderRandom	public	function	Orders the result set by a random value. Overrides SelectQueryInterface::orderRandom
SelectQueryExtender::preExecute	public	function	Generic preparation and validation for a SELECT query. Overrides SelectQueryInterface::preExecute
SelectQueryExtender::range	public	function	Restricts a query to a given range in the result set. Overrides SelectQueryInterface::range
SelectQueryExtender::rightJoin	public	function	Right Outer Join against another table in the database. Overrides SelectQueryInterface::rightJoin
SelectQueryExtender::union	public	function	Add another Select query to UNION to this one. Overrides SelectQueryInterface::union
SelectQueryExtender::uniqueIdentifier	public	function	Implements QueryPlaceholderInterface::uniqueIdentifier(). Overrides QueryPlaceholderInterface::uniqueIdentifier
SelectQueryExtender::where	public	function	Adds an arbitrary WHERE clause to the query. Overrides QueryConditionInterface::where
SelectQueryExtender::__call	public	function	Magic override for undefined methods.
SelectQueryExtender::__clone	public	function	Clone magic method. Overrides SelectQueryInterface::__clone
SelectQueryExtender::__toString	public	function

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class PagerDefault in Drupal 7

Hierarchy

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