Zend_Form set and validate field value manually - php

Question

I have a Zend_Form with a dropdown field.
When the user sets a value in the url this one should be selected as default value in this dropdown.
So what i do at the moment is this:
$parlang = $this->getRequest()->getParam('lang');
if($parlang){
$this->view->filterForm->getElement('ddLanguage')->setValue($parlang);
}
if ($this->getRequest()->isPost()) {
if($this->view->filterForm->isValid($_POST)){
...
...
...
No i want to check if the value of the variable is even a valid value for the dropdown? How can i check this in coorporation with the form validation. Yes i can check the variable against a array or so but this seems to be "fighting against the framework".
So what is the Zend way to do such a thing?
Edit:
My final solution for all who are interested, is:
$parlang = $this->getRequest()->getParam('lang');
if($parlang){
$ddLanguage = $this->view->filterForm->ddLanguage;
if($ddLanguage->isValid($parlang)){
$ddLanguage->setValue($parlang);
$language = $parlang;
}
}

Answer 1

I ran a quick test and it looks like one method you can use is Zend_Form_Element_Select::getMultiOption() to check if the language exists in the select values.
<?php
$parlang = $this->getRequest()->getParam('lang');
if ($parlang) {
$el = $this->view->filterForm->getElement('ddLanguage');
// attempt to get the option
// Returns null if no such option exists, otherwise returns a
// string with the display value for the option
if ($el->getMultiOption($parlang) !== null) {
$el->setValue($parlang);
}
}

Answer 2

If your Multiselect element contains a list of country, I would just populate a default in your element value according to the one in the URL.
In order to do so, you could create a custom Zend_Form_Element as follow:
class My_Form_Element_SelectCountry extends Zend_Form_Element_Select
{
protected $_translatorDisabled = true;
public function init()
{
$locale = Zend_Registry::get('Zend_Locale');
if (!$locale) {
throw new Exception('No locale set in registry');
}
$countries = Zend_Locale::getTranslationList('territory', $locale, 2);
unset($countries['ZZ']);
// fetch lang parameter and set US if there is no param
$request = Zend_Controller_Front::getInstance()->getRequest();
$lang = $request->getParam('lang', 'US');
// sort your country list
$oldLocale = setlocale(LC_COLLATE, '0');
setlocale(LC_COLLATE, 'en_US');
asort($countries, SORT_LOCALE_STRING);
setlocale(LC_COLLATE, $oldLocale);
// check weither the lang parameter is valid or not and add it to the list
if (isset($countries[$lang])) {
$paramLang = array($lang => $countries[$lang]);
$countries = array_merge($paramLang, $countries);
}
$this->setMultiOptions($countries);
}
}
You get the idea from this custom form.
If what you're trying to do isn't a Multiselect field filled by a country list but a list of language instead, then the logic is the same, you just need to change the call to the static method Zend_Locale::getTranslationList()and grab whatever information you need.
One more thing, if you just want a single element in your Multiselect element, then go for a Zend_Form_Element_Hidden.
It's a lot of "if" but I can't understand how looks like your Multiselect element exactly from your question.
Now let's take a look on the validation side, when you're using a Multiselect element, Zend_Framework automatically adds an InArray validator, which means that you don't have anything to do to check weither the data sent are correct or not. isValid is going to do it for you.
Weither a user let the default parameter and everything will be fine, or he modifies/deletes this parameter and the default parameter (en_US in this case, see code above) is going to be set as a default value for the Multiselect field.
To answer your last question, no it's not against the framework to check a variable set by a user and compare it with an array (from getTranslationList()for example). I would say it's even the recommended way to do things.