Merge pull request #12 from CottaCush/features/report-pagination

(Query): Implement pagination on report queries

src/generators/sql/SQLGenerator.php

@@ -25,6 +25,7 @@ class SQLGenerator implements GeneratorInterface
     const QUERY_ONE = 'queryOne';
     const QUERY_COLUMN = 'queryColumn';
     const QUERY_SCALAR = 'queryScalar';
+    const QUERY_LIMIT = 20;
 
     public function __construct($query, Connection $db = null)
     {
@@ -39,19 +40,33 @@ public function __construct($query, Connection $db = null)
     /**
      * @author Taiwo Ladipo <[email protected]>
      * @param string $function
+     * @param bool $paginate
+     * @param null $page
      * @return array
      * @throws SQLQueryGenerationException
      */
-    public function generateResult($function = self::QUERY_ALL)
+    public function generateResult($function = self::QUERY_ALL, $paginate = false, $page = null)
     {
         try {
             $this->openConnection();
-            $result = $this->db->createCommand($this->query)->{$function}();
+            $count = 0;
+            $this->query = rtrim($this->query, ';');
+            if ($paginate) {
+                if (!$page) { // first page of pagination
+                    $count =  $this->db->createCommand("SELECT COUNT(*) as total FROM ($this->query) a")
+                        ->{self::QUERY_SCALAR}();
+                }
+                $from = $page ? ($page - 1) * self::QUERY_LIMIT : 0;
+                $result = $this->db->createCommand("$this->query LIMIT $from, " . self::QUERY_LIMIT)
+                    ->{self::QUERY_ALL}();
+            } else {
+                $result = $this->db->createCommand($this->query)->{$function}();
+            }
             $this->closeConnection();
         } catch (Exception $e) {
             throw new SQLQueryGenerationException($e->getMessage());
         }
-        return $result;
+        return ['data' => $result, 'count' => $count];
     }
 
     /**

src/generators/sql/SQLQueryBuilderParser.php

@@ -3,8 +3,9 @@
 namespace CottaCush\Cricket\Generators\SQL;
 
 use CottaCush\Cricket\Interfaces\CricketQueryableInterface;
-use CottaCush\Cricket\Models\Query;
 use CottaCush\Cricket\Traits\ValueGetter;
+use yii\helpers\ArrayHelper;
+use CottaCush\Cricket\Models\Query;
 
 class SQLQueryBuilderParser
 {
@@ -18,25 +19,37 @@ class SQLQueryBuilderParser
 
     /**
      * @author Olawale Lawal <[email protected]>
+     * @author Taiwo Ladipo <[email protected]>
      * @param CricketQueryableInterface $report
      * @param array $placeholderValues
      * @param null $db
      * @param string $function
+     * @param array $paginationExtras
      * @return array
      * @throws \CottaCush\Cricket\Exceptions\SQLQueryGenerationException
      */
     public function parse(
         CricketQueryableInterface $report,
         $placeholderValues = [],
         $db = null,
-        $function = SQLGenerator::QUERY_ALL
+        $function = SQLGenerator::QUERY_ALL,
+        $paginationExtras = []
     ) {
         /** @var Query $queryObj */
         $queryObj = $report->query;
+        $page = ArrayHelper::getValue($paginationExtras, 'page');
+        $paginate = boolval(ArrayHelper::getValue($paginationExtras, 'paginate'));
+
         $shouldReplacePlaceholders = !empty($placeholderValues); //Should the placeholders be replaced in the query
         $this->hasInputPlaceholders = count($queryObj->inputPlaceholders);
 
-        $this->query = $queryObj->getQuery();
+        if (!empty($paginationExtras) && $page) {
+            $this->query = ArrayHelper::getValue($paginationExtras, 'query_string');
+            $this->hasPlaceholdersReplaced = true;
+        } else {
+            $this->query = $queryObj->getQuery();
+        }
+
         $data = [];
 
         $dashboardFilterPlaceholders = $queryObj->getDashboardFilterPlaceholders()->all();
@@ -49,7 +62,7 @@ public function parse(
             $data = $generator->generateResult($function);
         }
 
-        if (!$this->hasInputPlaceholders) { // Query has only session placeholders or none
+        if (!$this->hasInputPlaceholders && !$paginate) { // Report has only session placeholders or none
             $shouldReplacePlaceholders = true;
             $placeholders = $queryObj->sessionPlaceholders;
             $placeholderValues = [];
@@ -59,18 +72,19 @@ public function parse(
             }
         }
 
-        if ($shouldReplacePlaceholders) { //If there are placeholders to be injected into the query before execution
+        //If there are placeholders to be injected into the query before execution and not the first page
+        if ($shouldReplacePlaceholders && !$page) {
             $queryBuilder = new SQLQueryBuilder($queryObj, $placeholderValues);
             $this->query = $queryBuilder->buildQuery();
 
             $generator = new SQLGenerator($this->query, $db);
-            $data = $generator->generateResult($function);
+            $data = $generator->generateResult($function, $paginate, $page);
 
             $this->hasPlaceholdersReplaced = true;
         } else {
-            if (!$this->hasInputPlaceholders) { //No session placeholders and no submission
+            if (!$this->hasInputPlaceholders || $page) { //No session placeholders and no submission
                 $generator = new SQLGenerator($this->query, $db);
-                $data = $generator->generateResult($function);
+                $data = $generator->generateResult($function, $paginate, $page);
             }
         }
 

src/generators/sql/SQLQueryFilterFactory.php

@@ -133,7 +133,7 @@ private function generateDropdown($value = null)
         //Build the query from the report to get data
         $queryBuilder = new SQLQueryBuilder($dropdownQuery, $placeholderValues);
         $generator = new SQLGenerator($queryBuilder->buildQuery(), $this->database);
-        $data = $generator->generateResult();
+        $data = ArrayHelper::getValue($generator->generateResult(), 'data');
 
         if (count($data)) {
             $data = ArrayHelper::map($data, 'key', 'value');