Add argument to control the indentation level. (#17)

README.md

@@ -497,6 +497,31 @@ VarExporter::export(
 
 Export the current value of each `use()` variable as expression inside the exported closure.
 
+## Indentation
+
+You can use the 3rd argument of `VarExporter::export()` to control the indentation level. 
+This is useful when you want to use the generated code string to replace a placeholder in a template used to generate code files.
+
+So using output of `VarExporter::export(['foo' => 'bar'], 0, 1)` in the template below to replace `{{exported}}`
+
+```
+public foo() 
+{
+    $data = {{exported}};
+}
+```
+
+would result in
+
+```php
+public foo() 
+{
+    $data = [
+        'foo' => 'bar'
+    ];
+}
+```
+
 ## Error handling
 
 Any error occurring on `export()` will throw an `ExportException`:

src/Internal/GenericExporter.php

@@ -67,10 +67,18 @@ final class GenericExporter
      */
     public $trailingCommaInArray;
 
+    /**
+     * @psalm-readonly
+     *
+     * @var int
+     */
+    public $indentLevel;
+
     /**
      * @param int $options
+     * @param int Indentation level
      */
-    public function __construct(int $options)
+    public function __construct(int $options, int $indentLevel = 0)
     {
         $this->objectExporters[] = new ObjectExporter\StdClassExporter($this);
 
@@ -97,6 +105,8 @@ public function __construct(int $options)
         $this->inlineNumericScalarArray = (bool) ($options & VarExporter::INLINE_NUMERIC_SCALAR_ARRAY);
         $this->closureSnapshotUses      = (bool) ($options & VarExporter::CLOSURE_SNAPSHOT_USES);
         $this->trailingCommaInArray     = (bool) ($options & VarExporter::TRAILING_COMMA_IN_ARRAY);
+
+        $this->indentLevel = $indentLevel;
     }
 
     /**

src/Internal/ObjectExporter/ClosureExporter.php

@@ -54,7 +54,7 @@ public function export($object, \ReflectionObject $reflectionObject, array $path
         $closure = $this->getClosure($reflectionFunction, $ast, $file, $line, $path);
 
         $prettyPrinter = new ClosureExporter\PrettyPrinter();
-        $prettyPrinter->setVarExporterNestingLevel(count($path));
+        $prettyPrinter->setVarExporterNestingLevel(count($path) + $this->exporter->indentLevel);
 
         $code = $prettyPrinter->prettyPrintExpr($closure);
 

src/VarExporter.php

@@ -64,23 +64,33 @@ final class VarExporter
     public const TRAILING_COMMA_IN_ARRAY = 1 << 9;
 
     /**
-     * @param mixed $var     The variable to export.
-     * @param int   $options A bitmask of options. Possible values are `VarExporter::*` constants.
-     *                       Combine multiple options with a bitwise OR `|` operator.
+     * @param mixed $var       The variable to export.
+     * @param int   $options   A bitmask of options. Possible values are `VarExporter::*` constants.
+     *                         Combine multiple options with a bitwise OR `|` operator.
+     * @param int $indentLevel Indentation level.
      *
      * @return string
      *
      * @throws ExportException
      */
-    public static function export($var, int $options = 0) : string
+    public static function export($var, int $options = 0, int $indentLevel = 0) : string
     {
-        $exporter = new GenericExporter($options);
-
+        $exporter = new GenericExporter($options, $indentLevel);
         $lines = $exporter->export($var, [], []);
-        $export = implode(PHP_EOL, $lines);
+
+        if ($indentLevel < 1 || count($lines) < 2) {
+            $export = implode(PHP_EOL, $lines);
+        } else {
+            $firstLine = array_shift($lines);
+            $lines = array_map(function ($line) use ($indentLevel) {
+                return str_repeat('    ', $indentLevel) . $line;
+            }, $lines);
+
+            $export = $firstLine . PHP_EOL . implode(PHP_EOL, $lines);
+        }
 
         if ($options & self::ADD_RETURN) {
-            return 'return ' . $export . ';' .  PHP_EOL;
+            return 'return ' . $export . ';' . PHP_EOL;
         }
 
         return $export;

tests/VarExporterTest.php

@@ -287,4 +287,125 @@ public function testExportObjectWithCircularReference()
             ]
         ]);
     }
+
+    /**
+     * @dataProvider providerExportIndented
+     */
+    public function testExportIndented($var, $expected, $options)
+    {
+        $template = <<<'TPL'
+public foo ()
+{
+    $data = {{exported}};
+}
+TPL;
+
+        $exported = VarExporter::export($var, $options, 1);
+        $result = str_replace('{{exported}}', $exported, $template);
+
+        $this->assertEquals($expected, $result);
+    }
+
+    public function providerExportIndented()
+    {
+        // Array
+        $var = ['one' => ['hello', true], 'two' => 2];
+        $expected = <<<'PHP'
+public foo ()
+{
+    $data = [
+        'one' => [
+            'hello',
+            true
+        ],
+        'two' => 2
+    ];
+}
+PHP;
+        yield [$var, $expected, 0];
+
+        // Null
+        $var = null;
+        $expected = <<<'PHP'
+public foo ()
+{
+    $data = null;
+}
+PHP;
+        yield [$var, $expected, 0];
+
+        // Closure
+        $var = function () {
+            return 'Hello, world!';
+        };
+        $expected = <<<'PHP'
+public foo ()
+{
+    $data = function () {
+        return 'Hello, world!';
+    };
+}
+PHP;
+        yield [$var, $expected, 0];
+
+        $foo = 'bar';
+        $sub = function () use ($foo) {
+            return $foo;
+        };
+        $var = function () use ($sub) {
+            return $sub();
+        };
+
+        $expected = <<<'PHP'
+public foo ()
+{
+    $data = function () {
+        $sub = function () {
+            $foo = 'bar';
+            return $foo;
+        };
+        return $sub();
+    };
+}
+PHP;
+        yield [$var, $expected, VarExporter::CLOSURE_SNAPSHOT_USES];
+
+        $var = function () {
+            $a = 'Hello,
+World!';
+
+            $b = <<<TXT
+Hello,
+world!
+TXT;
+
+            $c = <<<'TXT'
+Hello,
+world!
+TXT;
+
+            return $a . $b . $c;
+        };
+
+        $expected = <<<'PHP'
+public foo ()
+{
+    $data = function () {
+        $a = 'Hello,
+World!';
+        $b = <<<TXT
+Hello,
+world!
+TXT;
+        $c = <<<'TXT'
+Hello,
+world!
+TXT;
+        return $a . $b . $c;
+    };
+}
+PHP;
+
+        yield [$var, $expected, 0];
+    }
 }