The value of the text area needs to be set via the "value" attribute, as with all other form ViewHelpers. = Examples =
Наследование: extends AbstractFormFieldViewHelper
 /**
  * @test
  */
 public function renderEscapesTextareaContent()
 {
     $mockTagBuilder = $this->createMock(TagBuilder::class);
     $mockTagBuilder->expects($this->once())->method('addAttribute')->with('name', 'NameOfTextarea');
     $this->viewHelper->expects($this->once())->method('registerFieldNameForFormTokenGeneration')->with('NameOfTextarea');
     $mockTagBuilder->expects($this->once())->method('setContent')->with('some <tag> & "quotes"');
     $mockTagBuilder->expects($this->once())->method('render');
     $this->viewHelper->injectTagBuilder($mockTagBuilder);
     $arguments = array('name' => 'NameOfTextarea', 'value' => 'some <tag> & "quotes"');
     $this->viewHelper->setArguments($arguments);
     $this->viewHelper->setViewHelperNode(new \Neos\FluidAdaptor\ViewHelpers\Fixtures\EmptySyntaxTreeNode());
     $this->viewHelper->initialize();
     $this->viewHelper->render();
 }