<?php

class Qs_Form_Element_PageAlias extends Zend_Form_Element_Xhtml
{
    public $helper = 'pageAlias';
    protected $_aliasValidatorOptions;
    protected $_sourceField;
    /**
     * Flag: autoregister alias validator?
     * @var bool
     */
    protected $_registerAliasValidator = true;
    protected $_defaultDescription = 'Allowed characters: a-z, A-Z, 0-9, "-", "_", "."';

    public function init()
    {
        if (false === $this->getFilter('StringTrim')) {
            $this->addFilter('StringTrim');
        }
        return $this;
    }

    public function getDefaultDescription()
    {
        return $this->_defaultDescription;
    }

    public function setDefaultDescription($defaultDescription)
    {
        $this->_defaultDescription = $defaultDescription;
        return $this;
    }

    /**
     * Set flag indicating whether or not to auto-register alias validator
     *
     * @param  bool $flag
     * @return Qs_Form_Element_PageAlias
     */
    public function setRegisterAliasValidator($flag)
    {
        $this->_registerAliasValidator = (bool) $flag;
        return $this;
    }

    /**
     * Set description for element
     *
     * @return Qs_Form_Element_PageAlias
     */
    protected function _initElementDescription()
    {
        if ($this->hasRegisterAliasValidator() && empty($this->_description)) {
            $this->_description = $this->_defaultDescription;
        }
        return $this;
    }

    /**
     * Get status of auto-register alias validator flag
     *
     * @return bool
     */
    public function hasRegisterAliasValidator()
    {
        return $this->_registerAliasValidator;
    }

    /**
     * Is the value provided valid?
     *
     * Autoregisters alias validator if necessary.
     *
     * @param  string $value
     * @param  mixed $context
     * @return bool
     * @throws Zend_Form_Element_Exception
     */
    public function isValid($value, $context = null)
    {
        if ($this->hasRegisterAliasValidator()) {
            if (!$this->getValidator('Alias')) {
                $options = $this->getAliasValidatorOptions();
                if (empty($options)) {
                    throw new Zend_Form_Element_Exception('Alias validator options is not defined');
                }
                $this->addValidator(
                    'Alias',
                    true,
                    array($options)
                );
            }
        }
        return parent::isValid($value, $context);
    }

    /**
     * Set options for alias validator
     *
     * @param array $options
     * @return Qs_Form_Element_PageAlias
     */
    public function setAliasValidatorOptions($options)
    {
        $this->_aliasValidatorOptions = $options;
        return $this;
    }

    /**
     * Return options for alias validator
     *
     * @return array
     */
    public function getAliasValidatorOptions()
    {
        return $this->_aliasValidatorOptions;
    }

    public function render(Zend_View_Interface $view = null)
    {
        $this->_initElementDescription();
        return parent::render($view);
    }
}