Document new environment variables and display options

components/var_dumper/advanced.rst

@@ -181,6 +181,94 @@ method. They also typically implement the
 them from re-implementing the logic required to walk through a
 :class:`Symfony\\Component\\VarDumper\\Cloner\\Data` object's internal structure.
 
+The :class:`Symfony\\Component\\VarDumper\\Dumper\\HtmlDumper` limits string
+length and nesting depth of the output to make it more readable. These options
+can be overriden by the third optional parameter of the
+:method:`dump(Data $data) <Symfony\\Component\\VarDumper\\Dumper\\DataDumperInterface::dump>`
+method::
+
+    use Symfony\Component\VarDumper\Dumper\HtmlDumper;
+
+    $output = fopen('php://memory', 'r+b');
+
+    $dumper = new HtmlDumper();
+    $dumper->dump($var, $output, array(
+        // 1 and 160 are the default values for these options
+        'maxDepth' => 1,
+        'maxStringLength' => 160
+    ));
+
+The output format of a dumper can be fine tuned by the two flags 
+``DUMP_STRING_LENGTH`` and ``DUMP_LIGHT_ARRAY`` which are passed as a bitmap
+in the third constructor argument. They can also be set via environment 
+variables when using
+:method:`assertDumpEquals($dump, $data, $message) <Symfony\\Component\\VarDumper\\Test\\VarDumperTestTrait::assertDumpEquals>`
+during unit testing.
+
+If ``DUMP_STRING_LENGTH`` is set, then the length of a string is displayed
+next to its content:
+
+.. code-block:: php
+
+    use Symfony\Component\VarDumper\Dumper\AbstractDumper;
+    use Symfony\Component\VarDumper\Dumper\CliDumper;
+
+    $var = array('test');
+    $dumper = new CliDumper();
+    echo $dumper->dump($var, true);
+
+    // array:1 [
+    //   0 => "test"
+    // ]
+
+    $dumper = new CliDumper(null, null, AbstractDumper::DUMP_STRING_LENGTH);
+    echo $dumper->dump($var, true);
+
+    // (added string length before the string)
+    // array:1 [
+    //   0 => (4) "test"
+    // ]
+
+If ``DUMP_LIGHT_ARRAY`` is set, then arrays are dumped in a shortened format
+similar to PHP's short array notation:
+
+.. code-block:: php
+
+    use Symfony\Component\VarDumper\Dumper\AbstractDumper;
+    use Symfony\Component\VarDumper\Dumper\CliDumper;
+
+    $var = array('test');
+    $dumper = new CliDumper();
+    echo $dumper->dump($var, true);
+
+    // array:1 [
+    //   0 => "test"
+    // ]
+
+    $dumper = new CliDumper(null, null, AbstractDumper::DUMP_LIGHT_ARRAY);
+    echo $dumper->dump($var, true);
+
+    // (no more array:1 prefix)
+    // [
+    //   0 => "test"
+    // ]
+
+If you would like to use both options, then you can just    combine them by
+using a the logical OR operator ``|``:
+
+.. code-block:: php
+
+    use Symfony\Component\VarDumper\Dumper\AbstractDumper;
+    use Symfony\Component\VarDumper\Dumper\CliDumper;
+
+    $var = array('test');
+    $dumper = new CliDumper(null, null, AbstractDumper::DUMP_STRING_LENGTH | AbstractDumper::DUMP_LIGHT_ARRAY);
+    echo $dumper->dump($var, true);
+
+    // [
+    //   0 => (4) "test"
+    // ]
+
 Casters
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