silverstripe-framework/core/PaginatedList.php
PingMetal 222ee6bde2
Fixed a pagination bug
Depending on the current page, a page not supposed to show up in the pagination summary can be skipped without returning a null value. It makes it difficult to know it is existent, but just skipped.
2016-12-19 14:54:06 +00:00

462 lines
11 KiB
PHP

<?php
/**
* A decorator that wraps around a data list in order to provide pagination.
*
* @package framework
* @subpackage view
*/
class PaginatedList extends SS_ListDecorator {
protected $request;
protected $getVar = 'start';
protected $pageLength = 10;
protected $pageStart;
protected $totalItems;
protected $limitItems = true;
/**
* Constructs a new paginated list instance around a list.
*
* @param SS_List $list The list to paginate. The getRange method will
* be used to get the subset of objects to show.
* @param array|ArrayAccess Either a map of request parameters or
* request object that the pagination offset is read from.
*/
public function __construct(SS_List $list, $request = array()) {
if (!is_array($request) && !$request instanceof ArrayAccess) {
throw new Exception('The request must be readable as an array.');
}
$this->setRequest($request);
parent::__construct($list);
}
/**
* Returns the GET var that is used to set the page start. This defaults
* to "start".
*
* If there is more than one paginated list on a page, it is neccesary to
* set a different get var for each using {@link setPaginationGetVar()}.
*
* @return string
*/
public function getPaginationGetVar() {
return $this->getVar;
}
/**
* Sets the GET var used to set the page start.
*
* @param string $var
*/
public function setPaginationGetVar($var) {
$this->getVar = $var;
return $this;
}
/**
* Returns the number of items displayed per page. This defaults to 10.
*
* @return int.
*/
public function getPageLength() {
return $this->pageLength;
}
/**
* Set the number of items displayed per page. Set to zero to disable paging.
*
* @param int $length
* @return $this
*/
public function setPageLength($length) {
$this->pageLength = $length;
return $this;
}
/**
* Sets the current page.
*
* @param int $page Page index beginning with 1
* @return $this
*/
public function setCurrentPage($page) {
$this->pageStart = ($page - 1) * $this->getPageLength();
return $this;
}
/**
* Returns the offset of the item the current page starts at.
*
* @return int
*/
public function getPageStart() {
$request = $this->getRequest();
if ($this->pageStart === null) {
if(
$request
&& isset($request[$this->getPaginationGetVar()])
&& $request[$this->getPaginationGetVar()] > 0
) {
$this->pageStart = (int)$request[$this->getPaginationGetVar()];
} else {
$this->pageStart = 0;
}
}
return $this->pageStart;
}
/**
* Sets the offset of the item that current page starts at. This should be
* a multiple of the page length.
*
* @param int $start
*/
public function setPageStart($start) {
$this->pageStart = $start;
return $this;
}
/**
* Returns the total number of items in the unpaginated list.
*
* @return int
*/
public function getTotalItems() {
if ($this->totalItems === null) {
$this->totalItems = count($this->list);
}
return $this->totalItems;
}
/**
* Sets the total number of items in the list. This is useful when doing
* custom pagination.
*
* @param int $items
*/
public function setTotalItems($items) {
$this->totalItems = $items;
return $this;
}
/**
* Sets the page length, page start and total items from a query object's
* limit, offset and unlimited count. The query MUST have a limit clause.
*
* @param SQLQuery $query
*/
public function setPaginationFromQuery(SQLQuery $query) {
if ($limit = $query->getLimit()) {
$this->setPageLength($limit['limit']);
$this->setPageStart($limit['start']);
$this->setTotalItems($query->unlimitedRowCount());
}
return $this;
}
/**
* Returns whether or not the underlying list is limited to the current
* pagination range when iterating.
*
* By default the limit method will be called on the underlying list to
* extract the subset for the current page. In some situations, if the list
* is custom generated and already paginated you don't want to additionally
* limit the list. You can use {@link setLimitItems} to control this.
*
* @return bool
*/
public function getLimitItems() {
return $this->limitItems;
}
/**
* @param bool $limit
*/
public function setLimitItems($limit) {
$this->limitItems = (bool) $limit;
return $this;
}
/**
* @return IteratorIterator
*/
public function getIterator() {
$pageLength = $this->getPageLength();
if($this->limitItems && $pageLength) {
$tmptList = clone $this->list;
return new IteratorIterator(
$tmptList->limit($pageLength, $this->getPageStart())
);
} else {
return new IteratorIterator($this->list);
}
}
/**
* Returns a set of links to all the pages in the list. This is useful for
* basic pagination.
*
* By default it returns links to every page, but if you pass the $max
* parameter the number of pages will be limited to that number, centered
* around the current page.
*
* @param int $max
* @return SS_List
*/
public function Pages($max = null) {
$result = new ArrayList();
if ($max) {
$start = ($this->CurrentPage() - floor($max / 2)) - 1;
$end = $this->CurrentPage() + floor($max / 2);
if ($start < 0) {
$start = 0;
$end = $max;
}
if ($end > $this->TotalPages()) {
$end = $this->TotalPages();
$start = max(0, $end - $max);
}
} else {
$start = 0;
$end = $this->TotalPages();
}
for ($i = $start; $i < $end; $i++) {
$result->push(new ArrayData(array(
'PageNum' => $i + 1,
'Link' => HTTP::setGetVar($this->getPaginationGetVar(), $i * $this->getPageLength()),
'CurrentBool' => $this->CurrentPage() == ($i + 1)
)));
}
return $result;
}
/**
* Returns a summarised pagination which limits the number of pages shown
* around the current page for visually balanced.
*
* Example: 25 pages total, currently on page 6, context of 4 pages
* [prev] [1] ... [4] [5] [[6]] [7] [8] ... [25] [next]
*
* Example template usage:
* <code>
* <% if MyPages.MoreThanOnePage %>
* <% if MyPages.NotFirstPage %>
* <a class="prev" href="$MyPages.PrevLink">Prev</a>
* <% end_if %>
* <% loop MyPages.PaginationSummary(4) %>
* <% if CurrentBool %>
* $PageNum
* <% else %>
* <% if Link %>
* <a href="$Link">$PageNum</a>
* <% else %>
* ...
* <% end_if %>
* <% end_if %>
* <% end_loop %>
* <% if MyPages.NotLastPage %>
* <a class="next" href="$MyPages.NextLink">Next</a>
* <% end_if %>
* <% end_if %>
* </code>
*
* @param int $context The number of pages to display around the current
* page. The number should be event, as half the number of each pages
* are displayed on either side of the current one.
* @return SS_List
*/
public function PaginationSummary($context = 4) {
$result = new ArrayList();
$current = $this->CurrentPage();
$total = $this->TotalPages();
// Make the number even for offset calculations.
if ($context % 2) {
$context--;
}
// If the first or last page is current, then show all context on one
// side of it - otherwise show half on both sides.
if ($current == 1 || $current == $total) {
$offset = $context;
} else {
$offset = floor($context / 2);
}
$left = max($current - $offset, 1);
$right = min($current + $offset, $total);
$range = range($current - $offset, $current + $offset);
if ($left + $context > $total) {
$left = $total - $context;
}
for ($i = 0; $i < $total; $i++) {
$link = HTTP::setGetVar($this->getPaginationGetVar(), $i * $this->getPageLength());
$num = $i + 1;
$emptyRange = $num != 1 && $num != $total && (
$num == $left - 1 || $num == $right + 1
);
if ($emptyRange) {
$result->push(new ArrayData(array(
'PageNum' => null,
'Link' => null,
'CurrentBool' => false
)));
} elseif ($num == 1 || $num == $total || in_array($num, $range)) {
$result->push(new ArrayData(array(
'PageNum' => $num,
'Link' => $link,
'CurrentBool' => $current == $num
)));
}
}
return $result;
}
/**
* @return int
*/
public function CurrentPage() {
$pageLength = $this->getPageLength();
return $pageLength
? floor($this->getPageStart() / $pageLength) + 1
: 1;
}
/**
* @return int
*/
public function TotalPages() {
$pageLength = $this->getPageLength();
return $pageLength
? ceil($this->getTotalItems() / $pageLength)
: min($this->getTotalItems(), 1);
}
/**
* @return bool
*/
public function MoreThanOnePage() {
return $this->TotalPages() > 1;
}
/**
* @return bool
*/
public function NotFirstPage() {
return $this->CurrentPage() != 1;
}
/**
* @return bool
*/
public function NotLastPage() {
return $this->CurrentPage() < $this->TotalPages();
}
/**
* Returns the number of the first item being displayed on the current
* page. This is useful for things like "displaying 10-20".
*
* @return int
*/
public function FirstItem() {
return ($start = $this->getPageStart()) ? $start + 1 : 1;
}
/**
* Returns the number of the last item being displayed on this page.
*
* @return int
*/
public function LastItem() {
$pageLength = $this->getPageLength();
if(!$pageLength) {
return $this->getTotalItems();
} elseif ($start = $this->getPageStart()) {
return min($start + $pageLength, $this->getTotalItems());
} else {
return min($pageLength, $this->getTotalItems());
}
}
/**
* Returns a link to the first page.
*
* @return string
*/
public function FirstLink() {
return HTTP::setGetVar($this->getPaginationGetVar(), 0);
}
/**
* Returns a link to the last page.
*
* @return string
*/
public function LastLink() {
return HTTP::setGetVar($this->getPaginationGetVar(), ($this->TotalPages() - 1) * $this->getPageLength());
}
/**
* Returns a link to the next page, if there is another page after the
* current one.
*
* @return string
*/
public function NextLink() {
if ($this->NotLastPage()) {
return HTTP::setGetVar($this->getPaginationGetVar(), $this->getPageStart() + $this->getPageLength());
}
}
/**
* Returns a link to the previous page, if the first page is not currently
* active.
*
* @return string
*/
public function PrevLink() {
if ($this->NotFirstPage()) {
return HTTP::setGetVar($this->getPaginationGetVar(), $this->getPageStart() - $this->getPageLength());
}
}
/**
* Returns the total number of items in the list
*/
public function TotalItems() {
return $this->getTotalItems();
}
/**
* Set the request object for this list
*
* @param SS_HTTPRequest
*/
public function setRequest($request) {
$this->request = $request;
}
/**
* Get the request object for this list
*/
public function getRequest() {
return $this->request;
}
}