Missing an entry on setting default values in Symfony Forms

[luebbert42]

Could we have an example how to set default values to a form element using form classes?

There are some answers on Stackoverflow (the question has 18.000 views!), but I am not sure about the answer quality (yet, trying to get it running ;-)):

http://stackoverflow.com/questions/7913086/how-to-set-default-value-for-form-field-in-symfony2

[wouterj]

There is already a data document in the reference of the Form type.

Some other type references should include this under "Inherit options", to make it clear. I propose at least:

• text
• number
• url

This can be easily done by adding a line to the table at the top of each reference:

+-------------+-------------------------------------------------------------------+
| Rendered as | ``input url`` field                                               |
+-------------+-------------------------------------------------------------------+
| Options     | - `default_protocol`_                                             |
+-------------+-------------------------------------------------------------------+
| Inherited   | - `max_length`_                                                   |
| options     | - `required`_                                                     |
|             | - `data`_                                                         |
|             | ...                                                               |
+-------------+-------------------------------------------------------------------+

And then in the "Inherit data" section, an include should be placed:

Inherited Options
-----------------

These options inherit from the :doc:`form </reference/forms/types/form>` type:

.. include:: /reference/forms/types/options/data.rst.inc

Related issue: #2360

[luebbert42]

There is another interesting answer on Stackoverflow covering a few options - does it make sense to include those in the documentation?
http://stackoverflow.com/questions/17986481/set-default-values-using-form-classes-in-symfony-2

[mtrojanowski]

I added the data option to the first three types mentioned by Wouter. Created the pull request just to make sure it's going the right direction. I will add the option to the other files as well.

As for the discussions on Stack Overflow I'm not sure if we need any more information in the documentation about the default values.

[mtrojanowski]

It's now complete with data option added to all of the types where it is meaningful. I skipped the types: file, submit, password, reset, button, search.

[xabbuh]

@luebbert42 which additional options do you mean?

[luebbert42]

I am not sure we are talking about the same thing: from my experience "data" sets a value ALWAYS, not only when the form element has no value yet.

Let's say you want to create a form "Add a new address" to your application. For some reason in 99% of the use cases the city is "Amsterdam". For convenience you want to preset the city atttribute to "Amsterdam", but the user can change it for the rare case his address is not in Amsterdam, but in Utrecht. . When he edits this special address later on, the form should show "Utrecht" of course, not Amsterdam. My original request was to document this case. 😄

[wouterj]

@luebbert42 then you should just use 'Amsterdam' as a default of your project

[mtrojanowski]

Agreed. I think the topic of default values in the fields is not tightly connected to the documentation of the form types themselves. I mean you can specify the default value in different places depending on what your form represents (is it connected to an entity, a contact form, etc.).

Still @luebbert42 I don't quite understand what do you mean by "sets the value always". You create a form and the defaults will be populated with what you have in the data option. When you bind the form to the request the values will be changed, right? Isn't it what the default value should do?

Sticking to your example. If this is some kind of address you will be editing afterwards it means that you're persisting it. Thus you probably have some kind of Address entity. In this entity you can set a default value for the city. When you create your form for a new address and pass the new "empty" entity to the form it will use the default value of the city field, and there's actually no need to use the data option on the FormType.

[luebbert42]

@wouterj excactly - where in the manual do I find the information how to do that for the different form elements?

[luebbert42]

@mtrojanowski have to try that with the current version - when I had the question 5 months ago it did not work that way OR I did it wrong (probably the latter) ;-)

[wouterj]

@luebbert42 it's the same for each form type, it's just using the object:

class Address
{
    protected $city = 'Amsterdam';
    protected $country = 'Nederland';

    // ... getters/setters
}

$address = new Address();
$form = $this->createFormBuilder($address)
    ->add('city', 'text')
    ->add('country', 'text')
    ->getForm();

Now, when rendering the form it has the defaults 'Amsterdam' and 'Nederland'. When changing this to 'Utrecht' and submitting the form (and you persist the object). The next time you generate the edit form, you use:

$address = $objectManager->find(...);
$form = $this->createFormBuilder($address)
    ->add('city', 'text')
    ->add('country', 'text')
    ->getForm();

And now the defaults are 'Utrecht' and 'Nederland'.

[luebbert42]

@wouterj Yes, that's an option for text field. How would you do that with elements displayed as checkbox or radiobuttons?

I would have expected that setting the data attr in the form builder class handles default values correctly for all elements. This is not the case. I tried it with a fresh 2.4 project. Using the "data" attributes for default values is still not working (or I am still doing it wrong ;-))

I have uploaded a tar.gz of the complete demo app directory if you want to try it out, too:
www.another-showroom.com/demo.tar.gz

The code is all generated by the Symfony console tool but a few characters in src/Acme/DemoBundle/Form/AddressType.php

Access the CRUD thingy through:
http://yourtestdomain/app_dev.php/address/

[wouterj]

With checkbox or radiobuttons, you don't use a string value but a boolean value:

class User
{
    protected $admin = false;
}

[luebbert42]

does it make sense to have that in the manual or cookbook?