Allow to stop chunk import early

Author: baopham

docs/import/chunk.md

@@ -38,5 +38,6 @@ Injected ExcelFile example:
         $import->chunk(250, function($results)
         {
             // do stuff
-        })
+            // or return true if you want to stop importing.
+        });
     }

src/Maatwebsite/Excel/Readers/LaravelExcelReader.php

@@ -495,6 +495,8 @@ public function chunk($size = 10, $callback = null)
         // Only read
         $this->reader->setReadDataOnly(true);
 
+        $break = false;
+
         // Start the chunking
         for ($startRow = 0; $startRow < $totalRows; $startRow += $chunkSize)
         {
@@ -512,11 +514,16 @@ public function chunk($size = 10, $callback = null)
             $results = $this->get()->slice($startIndex, $chunkSize);
 
             // Do a callback
-            if(is_callable($callback))
-                call_user_func($callback, $results);
+            if(is_callable($callback)) {
+                $break = call_user_func($callback, $results);
+            }
 
             $this->_reset();
             unset($this->excel, $results);
+
+            if ($break === true) {
+                break;
+            }
         }
     }
 

tests/Filters/ChunkReadFilterTest.php

@@ -41,6 +41,14 @@ public function testCanChunkCsv()
     }
 
 
+    public function testCanStopChunkEarly()
+    {
+        $this->assertCanStopChunkEarly(1,"sample.xls", 5);
+        $this->assertCanStopChunkEarly(1,"sample.xlsx", 2);
+        $this->assertCanStopChunkEarly(2,"sample.csv", 1);
+    }
+
+
     public function testCanChunkMultipleSheets()
     {
         $output = [];
@@ -85,4 +93,19 @@ private function assertCanChunkIntoGroups($expected_chunks, $file, $chunk_size)
         $this->assertEquals($expected_chunks, $rounds, "Expecting total chunks is $expected_chunks when chunk with size $chunk_size");
 
     }
-}
+
+    private function assertCanStopChunkEarly($expected_chunks, $file, $chunk_size)
+    {
+        $rounds = 0;
+
+        $this->excel->filter('chunk')->load(__DIR__ . "/files/{$file}")->chunk($chunk_size,function($results) use (&$rounds, $expected_chunks){
+            $rounds++;
+
+            if ($rounds === $expected_chunks) {
+                return true;
+            }
+        });
+
+        $this->assertEquals($expected_chunks, $rounds, "Expecting total chunks is $expected_chunks when chunk with size $chunk_size");
+    }
+}