[4.0][webservice] API pagination links

api/components/com_config/src/View/Application/JsonapiView.php

@@ -58,38 +58,49 @@ public function displayList(array $items = null)
 
 		$items = array_splice($items, $offset, $limit);
 
-		$firstPage = clone $currentUrl;
-		$firstPageQuery = $currentPageQuery;
-		$firstPageQuery['offset'] = 0;
-		$firstPage->setVar('page', $firstPageQuery);
-
-		$nextPage = clone $currentUrl;
-		$nextPageQuery = $currentPageQuery;
-		$nextOffset = $currentPageQuery['offset'] + $limit;
-		$nextPageQuery['offset'] = ($nextOffset > ($totalPagesAvailable * $limit)) ? $totalPagesAvailable - $limit : $nextOffset;
-		$nextPage->setVar('page', $nextPageQuery);
-
-		$previousPage = clone $currentUrl;
-		$previousPageQuery = $currentPageQuery;
-		$previousOffset = $currentPageQuery['offset'] - $limit;
-		$previousPageQuery['offset'] = $previousOffset >= 0 ? $previousOffset : 0;
-		$previousPage->setVar('page', $previousPageQuery);
-
-		$lastPage = clone $currentUrl;
-		$lastPageQuery = $currentPageQuery;
-		$lastPageQuery['offset'] = $totalPagesAvailable - $limit;
-		$lastPage->setVar('page', $lastPageQuery);
+		$this->document->addMeta('total-pages', $totalPagesAvailable)
+			->addLink('self', (string) $currentUrl);
+
+		// Check for first and previous pages
+		if ($offset > 0)
+		{
+			$firstPage = clone $currentUrl;
+			$firstPageQuery = $currentPageQuery;
+			$firstPageQuery['offset'] = 0;
+			$firstPage->setVar('page', $firstPageQuery);
+
+			$previousPage = clone $currentUrl;
+			$previousPageQuery = $currentPageQuery;
+			$previousOffset = $currentPageQuery['offset'] - $limit;
+			$previousPageQuery['offset'] = $previousOffset >= 0 ? $previousOffset : 0;
+			$previousPage->setVar('page', $previousPageQuery);
+
+			$this->document->addLink('first', $this->queryEncode((string) $firstPage))
+				->addLink('previous', $this->queryEncode((string) $previousPage));
+		}
+
+		// Check for next and last pages
+		if ($offset + $limit < $totalItemsCount)
+		{
+			$nextPage = clone $currentUrl;
+			$nextPageQuery = $currentPageQuery;
+			$nextOffset = $currentPageQuery['offset'] + $limit;
+			$nextPageQuery['offset'] = ($nextOffset > ($totalPagesAvailable * $limit)) ? $totalPagesAvailable - $limit : $nextOffset;
+			$nextPage->setVar('page', $nextPageQuery);
+
+			$lastPage = clone $currentUrl;
+			$lastPageQuery = $currentPageQuery;
+			$lastPageQuery['offset'] = ($totalPagesAvailable - 1) * $limit;
+			$lastPage->setVar('page', $lastPageQuery);
+
+			$this->document->addLink('next', $this->queryEncode((string) $nextPage))
+				->addLink('last', $this->queryEncode((string) $lastPage));
+		}
 
 		$collection = (new Collection($items, new JoomlaSerializer($this->type)));
 
 		// Set the data into the document and render it
-		$this->document->addMeta('total-pages', $totalPagesAvailable)
-			->setData($collection)
-			->addLink('self', (string) $currentUrl)
-			->addLink('first', (string) $firstPage)
-			->addLink('next', (string) $nextPage)
-			->addLink('previous', (string) $previousPage)
-			->addLink('last', (string) $lastPage);
+		$this->document->setData($collection);
 
 		return $this->document->render();
 	}

api/components/com_config/src/View/Component/JsonapiView.php

@@ -74,38 +74,49 @@ public function displayList(array $items = null)
 
 		$items = array_splice($items, $offset, $limit);
 
-		$firstPage = clone $currentUrl;
-		$firstPageQuery = $currentPageQuery;
-		$firstPageQuery['offset'] = 0;
-		$firstPage->setVar('page', $firstPageQuery);
-
-		$nextPage = clone $currentUrl;
-		$nextPageQuery = $currentPageQuery;
-		$nextOffset = $currentPageQuery['offset'] + $limit;
-		$nextPageQuery['offset'] = ($nextOffset > ($totalPagesAvailable * $limit)) ? $totalPagesAvailable - $limit : $nextOffset;
-		$nextPage->setVar('page', $nextPageQuery);
-
-		$previousPage = clone $currentUrl;
-		$previousPageQuery = $currentPageQuery;
-		$previousOffset = $currentPageQuery['offset'] - $limit;
-		$previousPageQuery['offset'] = $previousOffset >= 0 ? $previousOffset : 0;
-		$previousPage->setVar('page', $previousPageQuery);
-
-		$lastPage = clone $currentUrl;
-		$lastPageQuery = $currentPageQuery;
-		$lastPageQuery['offset'] = $totalPagesAvailable - $limit;
-		$lastPage->setVar('page', $lastPageQuery);
+		$this->document->addMeta('total-pages', $totalPagesAvailable)
+			->addLink('self', (string) $currentUrl);
+
+		// Check for first and previous pages
+		if ($offset > 0)
+		{
+			$firstPage = clone $currentUrl;
+			$firstPageQuery = $currentPageQuery;
+			$firstPageQuery['offset'] = 0;
+			$firstPage->setVar('page', $firstPageQuery);
+
+			$previousPage = clone $currentUrl;
+			$previousPageQuery = $currentPageQuery;
+			$previousOffset = $currentPageQuery['offset'] - $limit;
+			$previousPageQuery['offset'] = $previousOffset >= 0 ? $previousOffset : 0;
+			$previousPage->setVar('page', $previousPageQuery);
+
+			$this->document->addLink('first', $this->queryEncode((string) $firstPage))
+				->addLink('previous', $this->queryEncode((string) $previousPage));
+		}
+
+		// Check for next and last pages
+		if ($offset + $limit < $totalItemsCount)
+		{
+			$nextPage = clone $currentUrl;
+			$nextPageQuery = $currentPageQuery;
+			$nextOffset = $currentPageQuery['offset'] + $limit;
+			$nextPageQuery['offset'] = ($nextOffset > ($totalPagesAvailable * $limit)) ? $totalPagesAvailable - $limit : $nextOffset;
+			$nextPage->setVar('page', $nextPageQuery);
+
+			$lastPage = clone $currentUrl;
+			$lastPageQuery = $currentPageQuery;
+			$lastPageQuery['offset'] = ($totalPagesAvailable - 1) * $limit;
+			$lastPage->setVar('page', $lastPageQuery);
+
+			$this->document->addLink('next', $this->queryEncode((string) $nextPage))
+				->addLink('last', $this->queryEncode((string) $lastPage));
+		}
 
 		$collection = (new Collection($items, new JoomlaSerializer($this->type)));
 
 		// Set the data into the document and render it
-		$this->document->addMeta('total-pages', $totalPagesAvailable)
-			->setData($collection)
-			->addLink('self', (string) $currentUrl)
-			->addLink('first', (string) $firstPage)
-			->addLink('next', (string) $nextPage)
-			->addLink('previous', (string) $previousPage)
-			->addLink('last', (string) $lastPage);
+		$this->document->setData($collection);
 
 		return $this->document->render();
 	}

libraries/src/MVC/Controller/ApiController.php

@@ -200,15 +200,19 @@ public function displayList()
 	{
 		// Assemble pagination information (using recommended JsonApi pagination notation for offset strategy)
 		$paginationInfo = $this->input->get('page', [], 'array');
+		$limit          = null;
+		$offset         = null;
 
 		if (\array_key_exists('offset', $paginationInfo))
 		{
-			$this->modelState->set($this->context . '.limitstart', $paginationInfo['offset']);
+			$offset = $paginationInfo['offset'];
+			$this->modelState->set($this->context . '.limitstart', $offset);
 		}
 
 		if (\array_key_exists('limit', $paginationInfo))
 		{
-			$this->modelState->set($this->context . '.list.limit', $paginationInfo['limit']);
+			$limit = $paginationInfo['limit'];
+			$this->modelState->set($this->context . '.list.limit', $limit);
 		}
 
 		$viewType   = $this->app->getDocument()->getType();
@@ -243,16 +247,25 @@ public function displayList()
 		// Push the model into the view (as default)
 		$view->setModel($model, true);
 
+		if ($offset)
+		{
+			$model->setState('list.start', $offset);
+		}
+
 		/**
 		 * Sanity check we don't have too much data being requested as regularly in html we automatically set it back to
 		 * the last page of data. If there isn't a limit start then set
 		 */
-		if (!$this->input->getInt('limit', null))
+		if ($limit)
+		{
+			$model->setState('list.limit', $limit);
+		}
+		else
 		{
 			$model->setState('list.limit', $this->itemsPerPage);
 		}
 
-		if ($this->input->getInt('limitstart', 0) > $model->getTotal())
+		if (!is_null($offset) && $offset > $model->getTotal())
 		{
 			throw new Exception\ResourceNotFound;
 		}

libraries/src/MVC/View/JsonApiView.php

@@ -112,6 +112,11 @@ public function displayList(array $items = null)
 		/** @var \Joomla\CMS\MVC\Model\ListModel $model */
 		$model = $this->getModel();
 
+		// Get page query
+		$currentUrl = Uri::getInstance();
+		$currentPageDefaultInformation = ['offset' => 0, 'limit' => 20];
+		$currentPageQuery = $currentUrl->getVar('page', $currentPageDefaultInformation);
+
 		if ($items === null)
 		{
 			$items = [];
@@ -136,32 +141,46 @@ public function displayList(array $items = null)
 		}
 
 		// Set up links for pagination
-		$currentUrl = Uri::getInstance();
-		$currentPageDefaultInformation = array('offset' => $pagination->limitstart, 'limit' => $pagination->limit);
-		$currentPageQuery = $currentUrl->getVar('page', $currentPageDefaultInformation);
-		$totalPagesAvailable = ($pagination->pagesTotal * $pagination->limit);
-
-		$firstPage = clone $currentUrl;
-		$firstPageQuery = $currentPageQuery;
-		$firstPageQuery['offset'] = 0;
-		$firstPage->setVar('page', $firstPageQuery);
-
-		$nextPage = clone $currentUrl;
-		$nextPageQuery = $currentPageQuery;
-		$nextOffset = $currentPageQuery['offset'] + $pagination->limit;
-		$nextPageQuery['offset'] = ($nextOffset > ($totalPagesAvailable * $pagination->limit)) ? $totalPagesAvailable - $pagination->limit : $nextOffset;
-		$nextPage->setVar('page', $nextPageQuery);
-
-		$previousPage = clone $currentUrl;
-		$previousPageQuery = $currentPageQuery;
-		$previousOffset = $currentPageQuery['offset'] - $pagination->limit;
-		$previousPageQuery['offset'] = $previousOffset >= 0 ? $previousOffset : 0;
-		$previousPage->setVar('page', $previousPageQuery);
-
-		$lastPage = clone $currentUrl;
-		$lastPageQuery = $currentPageQuery;
-		$lastPageQuery['offset'] = $totalPagesAvailable - $pagination->limit;
-		$lastPage->setVar('page', $lastPageQuery);
+		$totalItemsCount = ($pagination->pagesTotal * $pagination->limit);
+
+		$this->document->addMeta('total-pages', $pagination->pagesTotal)
+			->addLink('self', (string) $currentUrl);
+
+		// Check for first and previous pages
+		if ($pagination->limitstart > 0)
+		{
+			$firstPage = clone $currentUrl;
+			$firstPageQuery = $currentPageQuery;
+			$firstPageQuery['offset'] = 0;
+			$firstPage->setVar('page', $firstPageQuery);
+
+			$previousPage = clone $currentUrl;
+			$previousPageQuery = $currentPageQuery;
+			$previousOffset = $currentPageQuery['offset'] - $pagination->limit;
+			$previousPageQuery['offset'] = $previousOffset >= 0 ? $previousOffset : 0;
+			$previousPage->setVar('page', $previousPageQuery);
+
+			$this->document->addLink('first', $this->queryEncode((string) $firstPage))
+				->addLink('previous', $this->queryEncode((string) $previousPage));
+		}
+
+		// Check for next and last pages
+		if ($pagination->limitstart + $pagination->limit < $totalItemsCount)
+		{
+			$nextPage = clone $currentUrl;
+			$nextPageQuery = $currentPageQuery;
+			$nextOffset = $currentPageQuery['offset'] + $pagination->limit;
+			$nextPageQuery['offset'] = ($nextOffset > ($pagination->pagesTotal * $pagination->limit)) ? $pagination->pagesTotal - $pagination->limit : $nextOffset;
+			$nextPage->setVar('page', $nextPageQuery);
+
+			$lastPage = clone $currentUrl;
+			$lastPageQuery = $currentPageQuery;
+			$lastPageQuery['offset'] = ($pagination->pagesTotal - 1) * $pagination->limit;
+			$lastPage->setVar('page', $lastPageQuery);
+
+			$this->document->addLink('next', $this->queryEncode((string) $nextPage))
+				->addLink('last', $this->queryEncode((string) $lastPage));
+		}
 
 		$collection = (new Collection($items, $this->serializer))
 			->fields([$this->type => $this->fieldsToRenderList]);
@@ -172,13 +191,7 @@ public function displayList(array $items = null)
 		}
 
 		// Set the data into the document and render it
-		$this->document->addMeta('total-pages', $pagination->pagesTotal)
-			->setData($collection)
-			->addLink('self', (string) $currentUrl)
-			->addLink('first', (string) $firstPage)
-			->addLink('next', (string) $nextPage)
-			->addLink('previous', (string) $previousPage)
-			->addLink('last', (string) $lastPage);
+		$this->document->setData($collection);
 
 		return $this->document->render();
 	}
@@ -244,4 +257,18 @@ protected function prepareItem($item)
 	{
 		return $item;
 	}
+
+	/**
+	 * Encode square brackets in the URI query, according to JSON API specification.
+	 *
+	 * @param   string  $query  The URI query
+	 *
+	 * @return  string
+	 *
+	 * @since   4.0.0
+	 */
+	protected function queryEncode($query)
+	{
+		return str_replace(array('[', ']'), array('%5B', '%5D'), $query);
+	}
 }