class PagerDefault
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
35 string references to 'PagerDefault'
- aggregator_feed_items_load in drupal-7.x/
modules/ aggregator/ aggregator.pages.inc - Loads and optionally filters feed items.
- blog_page_last in drupal-7.x/
modules/ blog/ blog.pages.inc - Menu callback; displays a Drupal page containing recent blog entries of all users.
- blog_page_user in drupal-7.x/
modules/ blog/ blog.pages.inc - Menu callback; displays a Drupal page containing recent blog entries of a given user.
- comment_admin_overview in drupal-7.x/
modules/ comment/ comment.admin.inc - Form builder for the comment overview administration form.
- comment_get_thread in drupal-7.x/
modules/ comment/ comment.module - Retrieve comments for a thread.
File
- drupal-7.x/
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 |
---|---|---|---|
PagerDefault:: |
protected | property | The count query that will be used for this pager. |
PagerDefault:: |
protected | property | The unique ID of this pager on this page. |
PagerDefault:: |
protected | property | The number of elements per page to allow. |
PagerDefault:: |
static | property | The highest element we've autogenerated so far. |
PagerDefault:: |
public | function | Specify the element ID for this pager query. |
PagerDefault:: |
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:: |
public | function |
Override the execute method. Overrides SelectQueryExtender:: |
PagerDefault:: |
public | function | Retrieve the count query for this pager. |
PagerDefault:: |
public | function | Specify the maximum number of elements per page for this query. |
PagerDefault:: |
public | function | Specify the count query object to use for this pager. |
PagerDefault:: |
public | function |
Overrides SelectQueryExtender:: |
SelectQueryExtender:: |
protected | property | The connection object on which to run this query. |
SelectQueryExtender:: |
protected | property | The placeholder counter. |
SelectQueryExtender:: |
protected | property | The SelectQuery object we are extending/decorating. |
SelectQueryExtender:: |
protected | property | A unique identifier for this query object. |
SelectQueryExtender:: |
public | function |
Adds an expression to the list of "fields" to be SELECTed. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Adds a field to the list to be SELECTed. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Join against another table in the database. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Adds additional metadata to the query. Overrides QueryAlterableInterface:: |
SelectQueryExtender:: |
public | function |
Adds a tag to a query. Overrides QueryAlterableInterface:: |
SelectQueryExtender:: |
public | function |
Gets a complete list of all values to insert into the prepared statement. Overrides QueryConditionInterface:: |
SelectQueryExtender:: |
public | function |
Compiles the saved conditions for later retrieval. Overrides QueryConditionInterface:: |
SelectQueryExtender:: |
public | function |
Check whether a condition has been previously compiled. Overrides QueryConditionInterface:: |
SelectQueryExtender:: |
public | function |
Helper function: builds the most common conditional clauses. Overrides QueryConditionInterface:: |
SelectQueryExtender:: |
public | function |
Gets a complete list of all conditions in this conditional clause. Overrides QueryConditionInterface:: |
SelectQueryExtender:: |
public | function |
Get the equivalent COUNT query of this query as a new query object. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Sets this query to be DISTINCT. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Sets a condition that the specified subquery returns values. Overrides QueryConditionInterface:: |
SelectQueryExtender:: |
public | function |
Enhance this object by wrapping it in an extender object. Overrides QueryExtendableInterface:: |
SelectQueryExtender:: |
public | function |
Add multiple fields from the same table to be SELECTed. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Add FOR UPDATE to the query. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Compiles and returns an associative array of the arguments for this prepared statement. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Returns a reference to the expressions array for this query. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Returns a reference to the fields array for this query. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Returns a reference to the group-by array for this query. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Retrieves a given piece of metadata. Overrides QueryAlterableInterface:: |
SelectQueryExtender:: |
public | function |
Returns a reference to the order by array for this query. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Returns a reference to the tables array for this query. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Returns a reference to the union queries for this query. This include
queries for UNION, UNION ALL, and UNION DISTINCT. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Groups the result set by the specified field. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Determines if a given query has all specified tags. Overrides QueryAlterableInterface:: |
SelectQueryExtender:: |
public | function |
Determines if a given query has any specified tag. Overrides QueryAlterableInterface:: |
SelectQueryExtender:: |
public | function |
Determines if a given query has a given tag. Overrides QueryAlterableInterface:: |
SelectQueryExtender:: |
public | function | |
SelectQueryExtender:: |
public | function | |
SelectQueryExtender:: |
public | function | |
SelectQueryExtender:: |
public | function |
Helper function to build most common HAVING conditional clauses. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function | |
SelectQueryExtender:: |
public | function |
Inner Join against another table in the database. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
function |
Sets a condition that the specified field be NOT NULL. Overrides QueryConditionInterface:: |
|
SelectQueryExtender:: |
function |
Sets a condition that the specified field be NULL. Overrides QueryConditionInterface:: |
|
SelectQueryExtender:: |
public | function |
Indicates if preExecute() has already been called on that object. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Default Join against another table in the database. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Left Outer Join against another table in the database. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Implements QueryPlaceholderInterface::nextPlaceholder(). Overrides QueryPlaceholderInterface:: |
SelectQueryExtender:: |
public | function |
Sets a condition that the specified subquery returns no values. Overrides QueryConditionInterface:: |
SelectQueryExtender:: |
public | function |
Orders the result set by a given field. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Orders the result set by a random value. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Generic preparation and validation for a SELECT query. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Restricts a query to a given range in the result set. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Right Outer Join against another table in the database. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Add another Select query to UNION to this one. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |
Implements QueryPlaceholderInterface::uniqueIdentifier(). Overrides QueryPlaceholderInterface:: |
SelectQueryExtender:: |
public | function |
Adds an arbitrary WHERE clause to the query. Overrides QueryConditionInterface:: |
SelectQueryExtender:: |
public | function | Magic override for undefined methods. |
SelectQueryExtender:: |
public | function |
Clone magic method. Overrides SelectQueryInterface:: |
SelectQueryExtender:: |
public | function |