Symfony\Component\DomCrawler\Field\ChoiceFormField::initialize PHP Method

    protected function initialize()
    {
        if ('input' !== $this->node->nodeName && 'select' !== $this->node->nodeName) {
            throw new \LogicException(sprintf('A ChoiceFormField can only be created from an input or select tag (%s given).', $this->node->nodeName));
        }
        if ('input' === $this->node->nodeName && 'checkbox' !== strtolower($this->node->getAttribute('type')) && 'radio' !== strtolower($this->node->getAttribute('type'))) {
            throw new \LogicException(sprintf('A ChoiceFormField can only be created from an input tag with a type of checkbox or radio (given type is %s).', $this->node->getAttribute('type')));
        }
        $this->value = null;
        $this->options = array();
        $this->multiple = false;
        if ('input' == $this->node->nodeName) {
            $this->type = strtolower($this->node->getAttribute('type'));
            $optionValue = $this->buildOptionValue($this->node);
            $this->options[] = $optionValue;
            if ($this->node->hasAttribute('checked')) {
                $this->value = $optionValue['value'];
            }
        } else {
            $this->type = 'select';
            if ($this->node->hasAttribute('multiple')) {
                $this->multiple = true;
                $this->value = array();
                $this->name = str_replace('[]', '', $this->name);
            }
            $found = false;
            foreach ($this->xpath->query('descendant::option', $this->node) as $option) {
                $optionValue = $this->buildOptionValue($option);
                $this->options[] = $optionValue;
                if ($option->hasAttribute('selected')) {
                    $found = true;
                    if ($this->multiple) {
                        $this->value[] = $optionValue['value'];
                    } else {
                        $this->value = $optionValue['value'];
                    }
                }
            }
            // if no option is selected and if it is a simple select box, take the first option as the value
            if (!$found && !$this->multiple && !empty($this->options)) {
                $this->value = $this->options[0]['value'];
            }
        }
    }