JForm Introduction

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Rob Schley

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Jan 26, 2009, 3:03:22 AM1/26/09
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Hi All,

Pardon the cross-post but I thought this was important enough to make sure it got to all the necessary places. Some of you may have noticed a new form package in the Joomla 1.6 trunk. The new form package provides a robust API for creating, populating, filtering, and validating form data via XML and PHP. The forms are created with XML similar to JParameter but JForm  is powerful enough to be used for a complete form, not just a set of parameters.

Filtering

By defining a filter attribute on each form field, JForm will allow you to completely sanitize your form input with one API call. The filter attribute will accept a variety of values including "unset" for read only data, "safehtml" for limited HTML support, "raw" for full HTML support, all JFilterInput::clean() mechanisms including "integer", "boolean", "base64", etc. as well as callbacks in the form of "my_callback_method" or "JFilterOutput::stringUrlSafe".

Validation

By defining a validate attribute for each form field, JForm will also validate form data. Some simple rules are available right now but there will probably be more coming in the near future. To validate an e-mail address, you can use validate="email" and the e-mail validator takes an optional attribute unique="unique" which will validate that the e-mail address is not in use by another user. If you use the unique option, you have to also specify a key for the user's table. It is easy to build your own validation rules and they can be combined to create some pretty sophisticated validation logic.

For example:

<field
name="id"
type="hidden"
filter="integer"
/>

<field
name="email1"
type="text"
id="email1"
label="PROFILE FORM EMAIL1 LABEL"
description="PROFILE FORM EMAIL1 LABEL"
message="PROFILE FORM EMAIL1 MESSAGE"
class="inputbox validate-email"
size="30"
default=""
required="true"
filter="string"
validate="email"
field="id"
unique="true"
/>

<field
name="email2"
type="text"
id="email2"
label="PROFILE FORM EMAIL2 LABEL"
description="PROFILE FORM EMAIL2 LABEL"
message="PROFILE FORM EMAIL2 MESSAGE"
class="inputbox validate-email"
size="30"
default=""
required="true"
filter="string"
validate="equals"
field="email1"
/>

The field definitions could be used in a user data edit screen to ensure that the user's e-mail address is unique to that user and that the email1 and email2 fields match. The email1 field will validate that the e-mail address is unique to the user and the email2 field will verify that it's supplied value matches the value given to email1. You can also specify custom validation messages via the message attribute.

Getting A Form

Let's assume you have an MVC component with a "forms" folder within the "models" folder. In the forms folder, you have a form file named "profile.xml". To get a instance of the form you would do something like:

// Get the form.
jimport('joomla.form.form');
JForm::addFormPath(JPATH_COMPONENT.DS.'models'.DS.'forms');
$form = &JForm::getInstance('jform', 'profile', true, array('array' => true));

JForm::addFormPath() works similarly to JModel::addIncludePath or JHtml::addIncludePath(). JForm::getInstance() returns a JForm instance. The first parameter is a name to identify the form by and will come into play when with the array option that you see in the forth parameter. The second parameter, "profile", tells JForm where to get the XML data from and the third option indicates that "profile" is a file name. Instead of specifying a file name, you can pass in straight XML into the second parameter and set the third parameter to false. The fourth parameter, array('array' => true), tells JForm to render the individual field names as an array. If our profile.xml contained the fields posted above, the field names would be jform[id], jform[email1], and jform[email2]. If the array option is set to false, the field names would be rendered as id, email1, and email2. 

The array option is very convenient because it makes loading the form data and running it through the filter/validator extremely quick. 

// Get the form.
jimport('joomla.form.form');
JForm::addFormPath(JPATH_COMPONENT.DS.'models'.DS.'forms');
$form = &JForm::getInstance('jform', 'profile', true, array('array' => true));

// Get the profile data.
$data = JRequest::getVar('jform', array(), 'post', 'array');

// Filter and validate the form data.
$data = $form->filter($data);
$return = $form->validate($data);

// Check for errors and save...

Notes

* We are still sorting out some of the error handling and validation warning feedback for PHP 5.2. The error handling will probably be updated in the near future to make distinguishing hard errors from validation errors easier.

* The library as a whole is quite powerful and I hope that it is fairly easy to understand but it will probably require some trial and error to really get the hang of. The newly committed com_weblinks admin component should serve as a useful example of how to use the new form package and the access control system will begin to use it more in the near future. 

That is all I can think of right now but I'm sure I've probably forgot something. If you guys have any questions, feel free to ask and I will do my best to help you out.

Best,
Rob Schley

orware

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Jan 26, 2009, 6:27:03 PM1/26/09
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This is a really nice addition...I had been wondering recently if
Joomla had built-in form validation like that and I guess now it
will :-).

Just another reason to start examining the com_weblinks source :-).

-Omar

On Jan 26, 12:03 am, Rob Schley <rob.sch...@community.joomla.org>
wrote:

cristiano.cucco

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Feb 6, 2009, 11:47:32 AM2/6/09
to Joomla! CMS Development
Hi,
could this library be added to Joomla 1.5 core without expecting J1.6
release?

Cristiano

Wilco Jansen

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Feb 6, 2009, 11:49:04 AM2/6/09
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You can take it, and implement it (we're GPL), but we won't add it to 1.5 since we're not adding new main features.

Regards, Wilco

Andrew Eddie

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Feb 21, 2009, 5:08:39 PM2/21/09
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It's part of our JXtended libraries (available from jxtended.com). If
you want to use it in 1.5, just grab our libraries.

Regards,
Andrew Eddie



2009/2/7 cristiano.cucco <cristia...@gmail.com>:

cristiano.cucco

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Feb 22, 2009, 12:43:27 PM2/22/09
to Joomla! CMS Development
There will be many differences between offical 1.6 JForm and Jxtended
version?
I mean If I develop a component using it, will be compatible with
future 1.6 release
or will I have to include again JXtende libraries?

Thank you,
Cristiano

On 21 Feb, 23:08, Andrew Eddie <mambob...@gmail.com> wrote:
> It's part of our JXtended libraries (available from jxtended.com).  If
> you want to use it in 1.5, just grab our libraries.
>
> Regards,
> Andrew Eddie
>
> 2009/2/7 cristiano.cucco <cristiano.cu...@gmail.com>:

Omar Ramos

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Feb 22, 2009, 3:02:59 PM2/22/09
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I believe in the JXtended libraries the class is named "JXForm" vs. the name "JForm" which will be the official name in Joomla 1.6.

The API should be similar for both classes so to convert your code later all you would need to do I believe is do some renaming in your code.

For Joomla 1.5, if you do decide to use the JXtended libraries, you will have to tell your users that they will need the libraries installed if your component is to work (or you can take parts of the library that you need and just include them in your code).

Hopefully that makes things a little clearer,

-Omar

Andrew Eddie

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Feb 23, 2009, 2:26:19 AM2/23/09
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The version in 1.6 is a bit cleaner than our current 1.5 version
(JxForm). We have a new version of libraries coming and what we will
do is keep that synchronised as much as possible with the 1.6 version.

And I've had this question before: you can by all means use the JForm
or JXForm code in your 1.5 components. It's all GPL.

Regards,
Andrew Eddie



2009/2/23 Omar Ramos <orw...@gmail.com>:
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