/home/edulekha/studygroup.edulekha.com/ow_core/form.php
<?php

/**
 * EXHIBIT A. Common Public Attribution License Version 1.0
 * The contents of this file are subject to the Common Public Attribution License Version 1.0 (the “License”);
 * you may not use this file except in compliance with the License. You may obtain a copy of the License at
 * http://www.oxwall.org/license. The License is based on the Mozilla Public License Version 1.1
 * but Sections 14 and 15 have been added to cover use of software over a computer network and provide for
 * limited attribution for the Original Developer. In addition, Exhibit A has been modified to be consistent
 * with Exhibit B. Software distributed under the License is distributed on an “AS IS” basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language
 * governing rights and limitations under the License. The Original Code is Oxwall software.
 * The Initial Developer of the Original Code is Oxwall Foundation (http://www.oxwall.org/foundation).
 * All portions of the code written by Oxwall Foundation are Copyright (c) 2011. All Rights Reserved.

 * EXHIBIT B. Attribution Information
 * Attribution Copyright Notice: Copyright 2011 Oxwall Foundation. All rights reserved.
 * Attribution Phrase (not exceeding 10 words): Powered by Oxwall community software
 * Attribution URL: http://www.oxwall.org/
 * Graphic Image as provided in the Covered Code.
 * Display of Attribution Information is required in Larger Works which are defined in the CPAL as a work
 * which combines Covered Code or portions thereof with code not governed by the terms of the CPAL.
 */

/**
 * Base form class.
 * 
 * @author Sardar Madumarov <madumarov@gmail.com>
 * @package ow_core
 * @since 1.0
 */
class Form
{
    const METHOD_POST = 'post';
    const METHOD_GET = 'get';
    const ENCTYPE_APP_FORM_URLENCODED = 'application/x-www-form-urlencoded';
    const ENCTYPE_MULTYPART_FORMDATA = 'multipart/form-data';
    const BIND_SUCCESS = 'success';
    const BIND_SUBMIT = 'submit';
    const AJAX_DATA_TYPE_JSON = 'json';
    const AJAX_DATA_TYPE_SCRIPT = 'script';
    const AJAX_DATA_TYPE_XML = 'xml';
    const AJAX_DATA_TYPE_HTML = 'html';
    /* -------------------------------------------------------------------------------------------------------------- */
    const ELEMENT_CSRF_TOKEN = "csrf_token";
    const ELEMENT_FORM_NAME = "form_name";

    /**
     * Form element attributes (id, name, etc).
     * 
     * @var array
     */
    protected $attributes = array();

    /**
     * Form elements list.
     *
     * @var array
     */
    protected $elements = array();

    /**
     * Form submit elements list <Submit/Button>.
     * 
     * @var array
     */
    protected $submitElements = array();

    /**
     * Form ajax flag.
     *
     * @var boolean
     */
    protected $ajax;

    /**
     * @var boolean
     */
    protected $ajaxResetOnSuccess;

    /**
     *
     * @var string
     */
    protected $ajaxDataType;

    /**
     * @var array
     */
    protected $bindedFunctions;

    /**
     * @var string
     */
    protected $emptyElementsErrorMessage;

    /**
     * Constructor.
     * 
     * @param string $name
     */
    public function __construct( $name )
    {
        $this->setId(UTIL_HtmlTag::generateAutoId('form'));
        $this->setMethod(self::METHOD_POST);
        $this->setAction('');
        $this->setAjaxResetOnSuccess(true);
        $this->setAjaxDataType(self::AJAX_DATA_TYPE_JSON);
        $this->bindedFunctions = array(self::BIND_SUBMIT => array(), self::BIND_SUCCESS => array());
        $this->setEmptyElementsErrorMessage(OW::getLanguage()->text('base', 'form_validate_common_error_message'));

        $formNameHidden = new HiddenField(self::ELEMENT_FORM_NAME);
        $formNameHidden->setValue($name);
        $this->addElement($formNameHidden);

        $formNameHidden = new CsrfHiddenField(self::ELEMENT_CSRF_TOKEN);
        $formNameHidden->setValue(UTIL_Csrf::generateToken());
        $this->addElement($formNameHidden);

        $this->setName($name);
    }

    /**
     * @return string
     */
    public function getId()
    {
        return isset($this->attributes['id']) ? $this->attributes['id'] : null;
    }

    /**
     * @return string
     */
    public function getName()
    {
        return isset($this->attributes['name']) ? $this->attributes['name'] : null;
    }

    /**
     * @return string
     */
    public function getEmptyElementsErrorMessage()
    {
        return $this->emptyElementsErrorMessage;
    }

    /**
     * @param string $message
     * @return Form
     */
    public function setEmptyElementsErrorMessage( $message )
    {
        $this->emptyElementsErrorMessage = $message;
        return $this;
    }

    /**
     * Sets form `id` attribute.
     * 
     * @param string $id
     * @return Form
     */
    public function setId( $id )
    {
        $this->attributes['id'] = trim($id);
        return $this;
    }

    /**
     * Sets form `name` attribute.
     *
     * @param string $name
     * @return Form
     * @throws InvalidArgumentException
     */
    public function setName( $name )
    {
        if ( !$name )
        {
            throw new InvalidArgumentException('Invalid form name!');
        }

        $this->getElement('form_name')->setValue($name);
        $this->attributes['name'] = trim($name);

        return $this;
    }

    /**
     * Sets form `action` url attribute.
     *
     * @param string $action
     * @return Form
     */
    public function setAction( $action )
    {
        $this->attributes['action'] = trim($action);

        return $this;
    }

    /**
     * @return string
     */
    public function getAction()
    {
        return isset($this->attributes['action']) ? $this->attributes['action'] : null;
    }

    /**
     * Sets form `method` attribute.
     *
     * @param string $method
     * @return Form
     */
    public function setMethod( $method )
    {
        if ( !in_array(trim($method), array(self::METHOD_GET, self::METHOD_POST)) )
        {
            throw new InvalidArgumentException('Invalid form method type!');
        }

        $this->attributes['method'] = trim($method);

        return $this;
    }

    /**
     * @return string
     */
    public function getMethod()
    {
        return isset($this->attributes['method']) ? $this->attributes['method'] : null;
    }

    /**
     * Sets form `enctype` attribute.
     *
     * @param string $enctype
     * @return Form
     */
    public function setEnctype( $enctype )
    {
        if ( !in_array(trim($enctype), array(self::ENCTYPE_APP_FORM_URLENCODED, self::ENCTYPE_MULTYPART_FORMDATA)) )
        {
            throw new InvalidArgumentException('Invalid form enctype!');
        }

        $this->attributes['enctype'] = trim($enctype);

        return $this;
    }

    /**
     * @return string
     */
    public function getEnctype()
    {
        return isset($this->attributes['enctype']) ? $this->attributes['enctype'] : null;
    }

    /**
     * Sets form ajax flag.
     *
     * @param boolean $isAjax
     * @return Form
     */
    public function setAjax( $ajax = true )
    {
        $this->ajax = (bool) $ajax;

        return $this;
    }

    /**
     * Checks if form is ajax.
     *
     * @return boolean
     */
    public function isAjax()
    {
        return $this->ajax;
    }

    /**
     * @return boolean
     */
    public function getAjaxResetOnSuccess()
    {
        return $this->ajaxResetOnSuccess;
    }

    /**
     * @param boolean $resetForm
     * @return Form
     */
    public function setAjaxResetOnSuccess( $resetForm )
    {
        $this->ajaxResetOnSuccess = (bool) $resetForm;
        return $this;
    }

    /**
     * @return string
     */
    public function getAjaxDataType()
    {
        return $this->ajaxDataType;
    }

    /**
     * @param string $ajaxDataType
     * @return Form
     */
    public function setAjaxDataType( $ajaxDataType )
    {
        $this->ajaxDataType = trim($ajaxDataType);
        return $this;
    }

    /**
     * @param string $eventType
     * @param callback $function
     */
    public function bindJsFunction( $eventType, $function )
    {
        $this->bindedFunctions[$eventType][] = $function;
    }

    /**
     * Adds form element.
     *
     * @param mixed
     * @return Form
     * @throws InvalidArgumentException
     * @throws LogicException
     * @throws InvalidArgumentException
     */
    public function addElement( $element )
    {
        if ( !$element instanceof FormElement )
        {
            throw new InvalidArgumentException('Provided element is not instance of FormElement class!');
        }

        if ( $element->getName() === null )
        {
            throw new LogicException('Form element with empty name was added!');
        }

        if ( array_key_exists($element->getName(), $this->elements) )
        {
            throw new LogicException('Duplicated form element name! Form element with name `' . $element->getName() . '` already exists!');
        }

        if ( $element instanceof Submit )
        {
            $this->submitElements[$element->getName()] = $element;
        }
        else
        {
            $this->elements[$element->getName()] = $element;
        }

        return $this;
    }

    /**
     * Returns form element by name.
     *
     * @param string $name
     * @return FormElement
     */
    public function getElement( $name )
    {
        return empty($this->elements[$name]) ? null : $this->elements[$name];
    }

    public function deleteElement( $elementName )
    {
        if ( empty($elementName) )
        {
            return;
        }

        if ( array_key_exists($elementName, $this->elements) )
        {
            unset($this->elements[$elementName]);
        }
    }

    /**
     * Returns all form elements.
     *
     * @return array
     */
    public function getElements()
    {
        return $this->elements;
    }

    /**
     * Returns form submit element by name.
     *
     * @param string $name
     * @return FormElement
     * @throws InvalidArgumentException
     */
    public function getSubmitElement( $name )
    {
        if ( !$name || !isset($this->submitElements[$name]) )
        {
            throw new InvalidArgumentException('Cant find element with name `' . $name . '`!');
        }

        return $this->submitElements[$name];
    }

    /**
     * Validates added form elements. 
     *
     * @param array $data
     * @return boolean
     * @throws InvalidArgumentException
     */
    public function isValid( $data )
    {
        $valid = true;

        if ( !is_array($data) )
        {
            throw new InvalidArgumentException('Array should be provided for validation!');
        }
        
        if ( $this->getElement(self::ELEMENT_CSRF_TOKEN) != null 
            && ( !isset($data[self::ELEMENT_CSRF_TOKEN]) || !UTIL_Csrf::isTokenValid($data[self::ELEMENT_CSRF_TOKEN] )) 
        )
        {
            $valid = false;
            //TODO refactor - remove message adding from Form class
            OW::getFeedback()->error(OW::getLanguage()->text("base", "invalid_csrf_token_error_message"));
        }

        /* @var $element FormElement */
        foreach ( $this->elements as $element )
        {
            $element->setValue(( isset($data[$element->getName()]) ? $data[$element->getName()] : null));

            if ( !$element->isValid() )
            {
                $valid = false;
            }
        }

        return $valid;
    }

    /**
     * Returns form element values.
     *
     * @return array
     */
    public function getValues()
    {
        $values = array();

        /* @var $element FormElement */
        foreach ( $this->elements as $element )
        {
            $values[$element->getName()] = $element->getValue();
        }

        return $values;
    }

    /**
     * Sets form element values.
     * 
     * @param array $values
     */
    public function setValues( array $values )
    {
        /* @var $element FormElement */
        foreach ( $this->elements as $element )
        {
            if ( isset($values[$element->getName()]) )
            {
                $element->setValue($values[$element->getName()]);
            }
        }
    }

    /**
     * Returns errors array for all form elements.
     *
     * @return array
     */
    public function getErrors()
    {
        $errors = array();

        /* @var $value FormElement */
        foreach ( $this->elements as $key => $value )
        {
            $errors[$key] = $value->getErrors();
        }

        return $errors;
    }

    /**
     * Resets all form elements values.
     *
     * @return Form
     */
    public function reset()
    {
        /* @var $element FormElement */
        foreach ( $this->elements as $element )
        {
            //TODO remove temp hardcode to avoid token reset
            if( $element->getName()  != self::ELEMENT_CSRF_TOKEN )
            {
                $element->setValue(null);
            }
        }

        return $this;
    }

    /**
     * Returns rendered HTML code of form object.
     *
     * @param string $formContent
     * @param string $decorator
     * @return string
     */
    public function render( $formContent, array $params = array() )
    {
        $formElementJS = '';

        /* @var $element FormElement */
        foreach ( $this->elements as $element )
        {
            $formElementJS .= $element->getElementJs() . PHP_EOL;
            $formElementJS .= "form.addElement(formElement);" . PHP_EOL;
        }

        $formInitParams = array(
            'id' => $this->getId(),
            'name' => $this->getName(),
            'reset' => $this->getAjaxResetOnSuccess(),
            'ajax' => $this->isAjax(),
            'ajaxDataType' => $this->getAjaxDataType(),
            'validateErrorMessage' => $this->emptyElementsErrorMessage,
        );

        $jsString = " var form = new OwForm(" . json_encode($formInitParams) . ");window.owForms[form.name] = form;
			" . PHP_EOL . $formElementJS . "

			if ( form.form ) 
			{
    			$(form.form).bind( 'submit', {form:form},
    					function(e){
    						return e.data.form.submitForm();
    					}
    			);
                        }
                        
                        OW.trigger('base.onFormReady.' + form.name, [], form);
                        OW.trigger('base.onFormReady', [form]);
		";

        foreach ( $this->bindedFunctions as $bindType => $binds )
        {
            if ( empty($binds) )
            {
                continue;
            }

            foreach ( $binds as $function )
            {
                $jsString .= "form.bind('" . trim($bindType) . "', " . $function . ");";
            }
        }

        OW::getDocument()->addOnloadScript($jsString, 10);

        $hiddenFieldString = '';

        /* @var $value OW_FormElement */
        foreach ( $this->elements as $value )
        {
            if ( $value instanceof HiddenField )
            {
                $hiddenFieldString .= $value->renderInput() . PHP_EOL;
            }
        }

        return UTIL_HtmlTag::generateTag('form', array_merge($this->attributes, $params), true,
                PHP_EOL . $hiddenFieldString . $formContent . PHP_EOL);
    }
}