Chapter 4 - Propel Integration

In a Web project, most forms are used to create or modify model objects. These objects are usually serialized in a database thanks to an ORM. Symfony's form system offers an additional layer for interfacing with Propel, symfony's built-in ORM, making the implementation of forms based on these model objects easier.

This chapter goes into detail about how to integrate forms with Propel object models. It is highly suggested to be already acquainted with Propel and its integration in symfony. If this is not the case, refer to the chapter Inside the Model Layer from the "The Definitive Guide to symfony" book.

Before we start

In this chapter, we will create an article management system. Let's start with the database schema. it is made of five tables: article, author, category, tag, and article_tag, as Listing 4-1 shows.

Listing 4-1 - Database Schema

// config/schema.yml
propel:
  article:
    id:           ~
    title:        { type: varchar(255), required: true }
    slug:         { type: varchar(255), required: true }
    content:      longvarchar
    status:       varchar(255)
    author_id:    { type: integer, required: true, foreignTable: author, foreignReference: id, OnDelete: cascade }
    category_id:  { type: integer, required: false, foreignTable: category, foreignReference: id, onDelete: setnull }
    published_at: timestamp
    created_at:   ~
    updated_at:   ~
    _uniques:
      unique_slug: [slug]
 
  author:
    id:           ~
    first_name:   varchar(20)
    last_name:    varchar(20)
    email:        { type: varchar(255), required: true }
    active:       boolean
 
  category:
    id:           ~
    name:         { type: varchar(255), required: true }
 
  tag:
    id:           ~
    name:         { type: varchar(255), required: true }
 
  article_tag:
    article_id:   { type: integer, foreignTable: article, foreignReference: id, primaryKey: true, onDelete: cascade }
    tag_id:       { type: integer, foreignTable: tag, foreignReference: id, primaryKey: true, onDelete: cascade }

Here are the relations between the tables:

• 1-n relation between the article table and the author table: an article is written by one and only one author
• 1-n relation between the article table and the category table: an article belongs to one or zero category
• n-n relation between the article and tag tables

Generating Form Classes

We want to edit the information of the article, author, category, and tag tables. To do so, we need to create forms linked to each of these tables and configure widgets and validators related to the database schema. Even if it is possible to create these forms manually, it is a long, tedious task, and overall, it forces repetition of the same kind of information in several files (column and field name, maximum size of column and fields, ...). Furthermore, each time we change the model, we will also have to change the related form class. Fortunately, the Propel plugin has a built-in task propel:build-forms that automates this process generating the forms related to the object model:

$ ./symfony propel:build-forms

During the form generation, the task creates one class per table with validators and widgets for each column using introspection of the model and taking into account relations between tables.

After executing these tasks, a file structure is created in the lib/form/ directory. Here are the files created for our example schema:

lib/
  form/
    BaseFormPropel.class.php
    ArticleForm.class.php
    ArticleTagForm.class.php
    AuthorForm.class.php
    CategoryForm.class.php
    TagForm.class.php
    base/
      BaseArticleForm.class.php
      BaseArticleTagForm.class.php
      BaseAuthorForm.class.php
      BaseCategoryForm.class.php
      BaseTagForm.class.php

The propel:build-forms task generates two classes for each table of the schema, one base class in the lib/form/base directory and one in the lib/form/ directory. For example, the author table, consists of BaseAuthorForm and AuthorForm classes that were generated in the files lib/form/base/BaseAuthorForm.class.php and lib/form/AuthorForm.class.php.

propel:
  _attributes: { noXsd: false, defaultIdMethod: none, package: lib.model.cms }
  # ...

Table below sums up the hierarchy among the different classes involved in the AuthorForm form definition.

In order to create or edit an object from the Author class, we will use the AuthorForm class, described in Listing 4-2. As you can notice, this class does not contain any methods as it inherits from the BaseAuthorForm which is generated through the configuration. The AuthorForm class is the class we will use to Customize and override the form configuration.

Listing 4-2 - AuthorForm Class

class AuthorForm extends BaseAuthorForm
{
  public function configure()
  {
  }
}

Listing 4-3 shows the BaseAuthorForm class with the validators and widgets generated introspecting the model for the author table.

Listing 4-3 - BaseAuthorForm Class representing the Form for the author table

class BaseAuthorForm extends BaseFormPropel
{
  public function setup()
  {
    $this->setWidgets(array(
      'id'         => new sfWidgetFormInputHidden(),
      'first_name' => new sfWidgetFormInputText(),
      'last_name'  => new sfWidgetFormInputText(),
      'email'      => new sfWidgetFormInputText(),
    ));
 
    $this->setValidators(array(
      'id'         => new sfValidatorPropelChoice(array('model' => 'Author', 'column' => 'id', 'required' => false)),
      'first_name' => new sfValidatorString(array('max_length' => 20, 'required' => false)),
      'last_name'  => new sfValidatorString(array('max_length' => 20, 'required' => false)),
      'email'      => new sfValidatorString(array('max_length' => 255)),
    ));
 
    $this->widgetSchema->setNameFormat('author[%s]');
 
    $this->errorSchema = new sfValidatorErrorSchema($this->validatorSchema);
 
    parent::setup();
  }
 
  public function getModelName()
  {
    return 'Author';
  }
}

The generated class looks very similar to the forms we have already created in the previous chapters, except for a few things:

• The base class is BaseFormPropel instead of BaseForm
• The validator and widget configuration takes place in the setup() method, rather than in the configure() method
• The getModelName() method returns the Propel class related to this form

abstract class BaseFormPropel extends sfFormPropel
{
  public function setup()
  {
    sfWidgetFormSchema::setDefaultFormFormatterName('div');
  }
}

The form field names are identical to the column names we set in the schema: id, first_name, last_name, and email.

For each column of the author table, the propel:build-forms task generates a widget and a validator according to the schema definition. The task always generates the most secure validators possible. Let's consider the id field. We could just check if the value is a valid integer. Instead the validator generated here allows us to also validate that the identifier actually exists (to edit an existing object) or that the identifier is empty (so that we could create a new object). This is a stronger validation.

The generated forms can be used immediately. Add a <?php echo $form ?> statement, and this will allow to create functional forms with validation without writing a single line of code.

Beyond the ability to quickly make prototypes, generated forms are easy to extend without having to modify the generated classes. This is thanks to the inheritance mechanism of the base and form classes.

At last at each evolution of the database schema, the task allows to generate again the forms to take into account the schema modifications, without overriding the Customization you might have made.

The CRUD Generator

Now that there are generated form classes, let's see how easy it is to create a symfony module to deal with the objects from a browser. We wish to create, modify, and delete objects from the Article, Author, Category, and Tag classes. Let's start with the module creation for the Author class. Even if we can manually create a module, the Propel plugin provides the propel:generate-module task which generates a CRUD module based on a Propel object model class. Using the form we generated in the previous section:

$ ./symfony propel:generate-module frontend author Author

The propel:generate-module takes three arguments:

• frontend : name of the application you want to create the module in
• author : name of the module you want to create
• Author : name of the model class you want to create the module for

In Listing 4-4, we see that the task generated five actions allowing us to list (index), create (create), modify (edit), save (update), and delete (delete) the objects of the Author class.

Listing 4-4 - The authorActions Class generated by the Task

// apps/frontend/modules/author/actions/actions.class.php
class authorActions extends sfActions
{
  public function executeIndex()
  {
    $this->authorList = AuthorPeer::doSelect(new Criteria());
  }
 
  public function executeCreate()
  {
    $this->form = new AuthorForm();
 
    $this->setTemplate('edit');
  }
 
  public function executeEdit($request)
  {
    $this->form = new AuthorForm(AuthorPeer::retrieveByPk($request->getParameter('id')));
  }
 
  public function executeUpdate($request)
  {
    $this->forward404Unless($request->isMethod('post'));
 
    $this->form = new AuthorForm(AuthorPeer::retrieveByPk($request->getParameter('id')));
 
    $this->form->bind($request->getParameter('author'));
    if ($this->form->isValid())
    {
      $author = $this->form->save();
 
      $this->redirect('author/edit?id='.$author->getId());
    }
 
    $this->setTemplate('edit');
  }
 
  public function executeDelete($request)
  {
    $this->forward404Unless($author = AuthorPeer::retrieveByPk($request->getParameter('id')));
 
    $author->delete();
 
    $this->redirect('author/index');
  }
}

In this module, the form life cycle is handled by three methods: create, edit and, update. It is also possible to ask the propel:generate-module task to generate only one method covering the three previous methods functionalities, with the option --non-atomic-actions:

$ ./symfony propel:generate-module frontend author Author --non-atomic-actions

The generated code using --non-atomic-actions (Listing 4-5) is more concise and less verbose.

Listing 4-5 - The authorActions Class generated with the --non-atomic-actions option

class authorActions extends sfActions
{
  public function executeIndex()
  {
    $this->authorList = AuthorPeer::doSelect(new Criteria());
  }
 
  public function executeEdit($request)
  {
    $this->form = new AuthorForm(AuthorPeer::retrieveByPk($request->getParameter('id')));
 
    if ($request->isMethod('post'))
    {
      $this->form->bind($request->getParameter('author'));
      if ($this->form->isValid())
      {
        $author = $this->form->save();
 
        $this->redirect('author/edit?id='.$author->getId());
      }
    }
  }
 
  public function executeDelete($request)
  {
    $this->forward404Unless($author = AuthorPeer::retrieveByPk($request->getParameter('id')));
 
    $author->delete();
 
    $this->redirect('author/index');
  }
}

The task also generated two templates, indexSuccess and editSuccess. The editSuccess template was generated without using the <?php echo $form ?> statement. We can modify this behavior, using the --non-verbose-templates:

$ ./symfony propel:generate-module frontend author Author --non-verbose-templates

This option is helpful during prototyping phases, as Listing 4-6 shows.

Listing 4-6 - The editSuccess Template

// apps/frontend/modules/author/templates/editSuccess.php
<?php $author = $form->getObject() ?>
<h1><?php echo $author->isNew() ? 'New' : 'Edit' ?> Author</h1>
 
<form action="<?php echo url_for('author/edit'.(!$author->isNew() ? '?id='.$author->getId() : '')) ?>" method="post" <?php $form->isMultipart() and print 'enctype="multipart/form-data" ' ?>>
  <table>
    <tfoot>
      <tr>
        <td colspan="2">
          &nbsp;<a href="<?php echo url_for('author/index') ?>">Cancel</a>
          <?php if (!$author->isNew()): ?>
            &nbsp;<?php echo link_to('Delete', 'author/delete?id='.$author->getId(), array('post' => true, 'confirm' => 'Are you sure?')) ?>
          <?php endif; ?>
          <input type="submit" value="Save" />
        </td>
      </tr>
    </tfoot>
    <tbody>
      <?php echo $form ?>
    </tbody>
  </table>
</form>

You can now open the URL /frontend_dev.php/author in a browser to view the generated module (Figure 4-1 and Figure 4-2). Take time to play with the interface. Thanks to the generated module you can list the authors, add a new one, edit, modify, and even delete. You will also notice that the validation rules are also working.

Figure 4-1 - Authors List

Figure 4-2 - Editing an Author with Validation Errors

We can now repeat the operation with the Article class:

$ ./symfony propel:generate-module frontend article Article --non-verbose-templates --non-atomic-actions

The generated code is quite similar to the code of the Author class. However, if you try to create a new article, the code throws a fatal error as you can see in Figure 4-3.

Figure 4-3 - Linked Tables must define the __toString() method

The ArticleForm form uses the sfWidgetFormPropelSelect widget to represent the relation between the Article object and the Author object. This widget creates a drop-down list with the authors. During the display, the authors objects are converted into a string of characters using the __toString() magic method, which must be defined in the Author class as shown in Listing 4-7.

Listing 4-7 - Implementing the __toString() method for the Author class

class Author extends BaseAuthor
{
  public function __toString()
  {
    return $this->getFirstName().' '.$this->getLastName();
  }
}

Just like the Author class, you can create __toString() methods for the other classes of our model: Article, Category, and Tag.

The Figure 4-4 Shows how to create an article after having implemented the __toString() method.

Figure 4-4 - Creating an Article

Customizing the generated Forms

The propel:build-forms and propel:generate-module tasks let us create functional symfony modules to list, create, edit, and delete model objects. These modules are taking into account not only the validation rules of the model but also the relationships between tables. All of this happens without writing a single line of code!

The time has now come to customize the generated code. If the form classes are already considering many elements, some aspects will need to be customized.

Configuring validators and widgets

Let's start with configuring the validators and widgets generated by default.

The ArticleForm form has a slug field. The slug is a string of characters that uniquely representing the article in the URL. For instance, the slug of an article whose title is "Optimize the developments with symfony" is 12-optimize-the-developments-with-symfony, 12 being the article id. This field is usually automatically computed when the object is saved, depending on the title, but it has the potential to be explicitly overridden by the user. Even if this field is required in the schema, it can not be compulsory to the form. That is why we modify the validator and make it optional, as in Listing 4-8. We will also customize the content field increasing its size and forcing the user to type in at least five characters.

Listing 4-8 - Customizing Validators and Widgets

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    // ...
 
    $this->validatorSchema['slug']->setOption('required', false);
    $this->validatorSchema['content']->setOption('min_length', 5);
 
    $this->widgetSchema['content']->setAttributes(array('rows' => 10, 'cols' => 40));
  }
}

We use here the validatorSchema and widgetSchema objects as PHP arrays. These arrays are taking the name of a field as key and return respectively the validator object and the related widget object. We can then Customize individually fields and widgets.

To make sure two articles can not have the same slug, a uniqueness constraint has been added in the schema definition. This constraint on the database level is reflected in the ArticleForm form using the sfValidatorPropelUnique validator. This validator can check the uniqueness of any form field. It is helpful among other things to check the uniqueness of an email address of a login for instance. Listing 4-9 shows how to use it in the ArticleForm form.

Listing 4-9 - Using the sfValidatorPropelUnique validator to check the Uniqueness of a field

class BaseArticleForm extends BaseFormPropel
{
  public function setup()
  {
    // ...
 
    $this->validatorSchema->setPostValidator(
      new sfValidatorPropelUnique(array('model' => 'Article', 'column' => array('slug')))
    );
  }
}

The sfValidatorPropelUnique validator is a postValidator running on the whole data after the individual validation of each field. In order to validate the slug uniqueness, the validator must be able to access, not only the slug value, but also the value of the primary key(s). Validation rules are indeed different throughout the creation and the edition since the slug can stay the same during the update of an article.

Let's Customize now the active field of the author table, used to know if an author is active. Listing 4-10 shows how to exclude inactive authors from the ArticleForm form, modifying the criteria option of the sfWidgetPropelSelect widget connected to the author_id field. The criteria option accepts a Propel Criteria object, allowing to narrow down the list of available options in the rolling list.

Listing 4-10 - Customizing the sfWidgetPropelSelect widget

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    // ...
 
    $authorCriteria = new Criteria();
    $authorCriteria->add(AuthorPeer::ACTIVE, true);
 
    $this->widgetSchema['author_id']->setOption('criteria', $authorCriteria);
  }
}

Even if the widget customization can make us narrow down the list of available options, we must not forget to consider this narrowing on the validator level, as shown in Listing 4-11. Like the sfWidgetProperSelect widget, the sfValidatorPropelChoice validator accepts a criteria option to narrow down the options valid for a field.

Listing 4-11 - Customizing the sfValidatorPropelChoice validator

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    // ...
 
    $authorCriteria = new Criteria();
    $authorCriteria->add(AuthorPeer::ACTIVE, true);
 
    $this->widgetSchema['author_id']->setOption('criteria', $authorCriteria);
    $this->validatorSchema['author_id']->setOption('criteria', $authorCriteria);
  }
}

In the previous example we defined the Criteria object directly in the configure() method. In our project, this criteria will certainly be helpful in other circumstances, so it is better to create a getActiveAuthorsCriteria() method within the AuthorPeer class and to call this method from ArticleForm as Listing 4-12 shows.

Listing 4-12 - Refactoring the Criteria in the Model

class AuthorPeer extends BaseAuthorPeer
{
  static public function getActiveAuthorsCriteria()
  {
    $criteria = new Criteria();
    $criteria->add(AuthorPeer::ACTIVE, true);
 
    return $criteria;
  }
}
 
class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    $authorCriteria = AuthorPeer::getActiveAuthorsCriteria();
    $this->widgetSchema['author_id']->setOption('criteria', $authorCriteria);
    $this->validatorSchema['author_id']->setOption('criteria', $authorCriteria);
  }
}

Changing validator

The email being defined as a varchar(255) in the schema, symfony created a sfValidatorString() validator restraining the maximum length to 255 characters. This field is also supposed to receive a valid email, Listing 4-14 replaces the generated validator with a sfValidatorEmail validator.

Listing 4-13 - Changing the email field Validator of the AuthorForm class

class AuthorForm extends BaseAuthorForm
{
  public function configure()
  {
    $this->validatorSchema['email'] = new sfValidatorEmail();
  }
}

Adding a validator

We observed in the previous chapter how to modify the generated validator. But in the case of the email field, it would be useful to keep the maximum length validation. In Listing 4-14, we use the sfValidatorAnd validator to guarantee the email validity and check the maximum length allowed for the field.

Listing 4-14 - Using a multiple Validator

class AuthorForm extends BaseAuthorForm
{
  public function configure()
  {
    $this->validatorSchema['email'] = new sfValidatorAnd(array(
      new sfValidatorString(array('max_length' => 255)),
      new sfValidatorEmail(),
    ));
  }
}

The previous example is not perfect, because if we decide later to modify the length of the email field in the database schema, we will have to think about doing it also in the form. Instead of replacing the generated validator, it is better to add one, as shown in Listing 4-15.

Listing 4-15 - Adding a Validator

class AuthorForm extends BaseAuthorForm
{
  public function configure()
  {
    $this->validatorSchema['email'] = new sfValidatorAnd(array(
      $this->validatorSchema['email'],
      new sfValidatorEmail(),
    ));
  }
}

Changing widget

In the database schema, the status field of the article table stores the article status as a string of characters. The possible values were defined in the ArticePeer class, as shown in Listing 4-16.

Listing 4-16 - Defining available Statuses in the ArticlePeer class

class ArticlePeer extends BaseArticlePeer
{
  static protected $statuses = array('draft', 'online', 'offline');
 
  static public function getStatuses()
  {
    return self::$statuses;
  }
 
  // ...
}

When editing an article, the status field must be represented as a drop-down list instead of a text field. To do so, let's change the widget we used, as shown in Listing 4-17.

Listing 4-17 - Changing the Widget for the status field

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    $this->widgetSchema['status'] = new sfWidgetFormSelect(array('choices' => ArticlePeer::getStatuses()));
  }
}

To be thorough we must also change the validator to make sure the chosen status actually belongs to the list of possible options (Listing 4-18).

Listing 4-18 - Modifying the status Field Validator

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    $statuses = ArticlePeer::getStatuses();
 
    $this->widgetSchema['status'] = new sfWidgetFormSelect(array('choices' => $statuses));
 
    $this->validatorSchema['status'] = new sfValidatorChoice(array('choices' => array_keys($statuses)));
  }
}

Deleting a field

The article table has two special columns, created_at and updated_at, whose update is automatically handled by Propel. We must then delete them from the form as Listing 4-19 show, to prevent the user from modifying them.

Listing 4-19 - Deleting a Field

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    unset($this->validatorSchema['created_at']);
    unset($this->widgetSchema['created_at']);
 
    unset($this->validatorSchema['updated_at']);
    unset($this->widgetSchema['updated_at']);
  }
}

In order to delete a field, it is necessary to delete its validator and its widget. Listing 4-20 shows how it is also possible to delete both in one action, using the form as a PHP array.

Listing 4-20 - Deleting a Field using the Form as a PHP Array

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    unset($this['created_at'], $this['updated_at']);
  }
}

Sum up

To sum up, Listing 4-21 and Listing 4-22 show the ArticleForm and AuthorForm forms as we customize them.

Listing 4-21 - ArticleForm Form

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    $authorCriteria = AuthorPeer::getActiveAuthorsCriteria();
 
    // widgets
    $this->widgetSchema['content']->setAttributes(array('rows' => 10, 'cols' => 40));
    $this->widgetSchema['status'] = new sfWidgetFormSelect(array('choices' => ArticlePeer::getStatuses()));
    $this->widgetSchema['author_id']->setOption('criteria', $authorCriteria);
 
    // validators
    $this->validatorSchema['slug']->setOption('required', false);
    $this->validatorSchema['content']->setOption('min_length', 5);
    $this->validatorSchema['status'] = new sfValidatorChoice(array('choices' => array_keys(ArticlePeer::getStatuses())));
    $this->validatorSchema['author_id']->setOption('criteria', $authorCriteria);
 
    unset($this['created_at']);
    unset($this['updated_at']);
  }
}

Listing 4-22 - AuthorForm Form

class AuthorForm extends BaseAuthorForm
{
  public function configure()
  {
    $this->validatorSchema['email'] = new sfValidatorAnd(array(
      $this->validatorSchema['email'],
      new sfValidatorEmail(),
    ));
  }
}

Using the propel:build-forms allows to automatically generate most of the elements letting forms introspect the object model. This automatization is helpful for several reasons:

• It makes the developer's life easier, saving him from a repetitive and redundant work. He can then focus on the validators and widget Customization according to the project's specific business rules .

• Besides, when the database schema is updated, the generated forms will be automatically updated. The developer will just have to tune the customization they made.

The next section will describe the customization of actions and templates generated by the propel:generate-module task.

Form Serialization

The previous section show us how to customize forms generated by the task propel:build-forms. In the current section, we will customize the life cycle of forms, starting from the code generated by the propel:generate-module task.

Default values

A Propel form instance is always connected to a Propel object. The linked Propel object always belongs to the class returned by the getModelName() method. For instance, the AuthorForm form can only be linked to objects belonging to the Author class. This object is either an empty object (a blank instance of the Author class), or the object sent to the constructor as first argument. Whereas the constructor of an "average" form takes an array of values as first argument, the constructor of a Propel form takes a Propel object. This object is used to define each form field default value. The getObject() method returns the object related to the current instance and the isNew() method allows to know if the object was sent via the constructor:

// creating a new object
$authorForm = new AuthorForm();
 
print $authorForm->getObject()->getId(); // outputs null
print $authorForm->isNew();              // outputs true
 
// modifying an existing object
$author = AuthorPeer::retrieveByPk(1);
$authorForm = new AuthorForm($author);
 
print $authorForm->getObject()->getId(); // outputs 1
print $authorForm->isNew();              // outputs false

Handling life cycle

As we observed at the beginning of the chapter, the edit action, shown in Listing 4-23, handles the form life cycle.

Listing 4-23 - The executeEdit Method of the author Module

// apps/frontend/modules/author/actions/actions.class.php
class authorActions extends sfActions
{
  // ...
 
  public function executeEdit($request)
  {
    $author = AuthorPeer::retrieveByPk($request->getParameter('id'));
    $this->form = new AuthorForm($author);
 
    if ($request->isMethod('post'))
    {
      $this->form->bind($request->getParameter('author'));
      if ($this->form->isValid())
      {
        $author = $this->form->save();
 
        $this->redirect('author/edit?id='.$author->getId());
      }
    }
  }
}

Even if the edit action looks like the actions we might have describe in the previous chapters, we can point a few differences:

• A Propel object from the Author class is sent as first argument to the form constructor:

  $author = AuthorPeer::retrieveByPk($request->getParameter('id'));
  $this->form = new AuthorForm($author);

• The widgets name attribute format is automatically customized to allow the retrieval of the input data in a PHP array named after the related table (author):

  $this->form->bind($request->getParameter('author'));

• When the form is valid, a mere call to the save() method creates or updates the Propel object related to the form:

  $author = $this->form->save();

Creating and Modifying a Propel Object

Listing 4-23 code handles with a single method the creation and modification of objects from the Author class:

• Creation of a new Author object:

  • The edit action is called with no id parameter ($request->getParameter('id') is null)

  • The call to the retrieveByPk() therefore sends null

  • The form object is then linked to an empty Author Propel object

  • The $this->form->save() call creates consequently a new Author object when a valid form is submitted

• Modification of an existing Author object:

  • The edit action is called with an id parameter ($request->getParameter('id') standing for the primary key the Author object is to modify)

  • The call to the retriveByPk() method returns the Author object related to the primary key

  • The form object is therefore linked to the previously found object

  • The $this->form->save() call updates the Author object when a valid form is submitted

The save() method

When a Propel form is valid, the save() method updates the related object and stores it in the database. This method actually stores not only the main object but also the potentially related objects. For instance, the ArticleForm form updates the tags connected to an article. The relation between the article table and the tag table being a n-n relation, the tags related to an article are saved in the article_tag table (using the saveArticleTagList() generated method).

In order to certify a consistent serialization, the save() method includes every updates in one transaction.

class articleActions extends sfActions
{
  public function executeCreate(sfWebRequest $request)
  {
    $this->form = new ArticleForm();
 
    if ($request->isMethod('post') && $this->form->bindAndSave($request->getParameter('article')))
    {
      $this->redirect('article/created');
    }
  }
}

Handling the files upload

The save() method automatically updates the Propel objects but can not handle the side elements as managing the file upload.

Let's see how to attach a file to each article. Files are stored in the web/uploads directory and a reference to the file path is kept in the file field of the article table, as shown in Listing 4-24.

Listing 4-24 - Schema for the article Table with associated File

// config/schema.yml
propel:
  article:
    // ...
    file: varchar(255)

After every schema update, you need to update the object model, the database and the related forms:

$ ./symfony propel:build-all

Listing 4-25 shows how to modify the ArticleForm class in order to link a widget and a validator to the file field.

Listing 4-25 - Modifying the file Field of the ArticleForm form.

class ArticleForm extends BaseArticleForm
{
  public function configure()
  {
    // ...
 
    $this->widgetSchema['file'] = new sfWidgetFormInputFile();
    $this->validatorSchema['file'] = new sfValidatorFile();
  }
}

As for every form allowing to upload a file, does not forget to add also the enctype attribute to the form tag of the template (see Chapter 2 for further informations concerning file upload management).

Listing 4-26 shows the modifications to apply when saving the form to upload the file onto the server and store its path in the article object.

Listing 4-26 - Saving the article Object and the File uploaded in the Action

public function executeEdit($request)
{
  $author = ArticlePeer::retrieveByPk($request->getParameter('id'));
  $this->form = new ArticleForm($author);
 
  if ($request->isMethod('post'))
  {
    $this->form->bind($request->getParameter('article'), $request->getFiles('article'));
    if ($this->form->isValid())
    {
      $file = $this->form->getValue('file');
      $filename = sha1($file->getOriginalName()).$file->getExtension($file->getOriginalExtension());
      $file->save(sfConfig::get('sf_upload_dir').'/'.$filename);
 
      $article = $this->form->save();
 
      $this->redirect('article/edit?id='.$article->getId());
    }
  }
}

Saving the uploaded file on the filesystem allows the sfValidatedFile object to know the absolute path to the file. During the call to the save() method, the fields values are used to update the related object and, as for the file field, the sfValidatedFile object is converted in a character string thanks to the __toString() method, sending back the absolute path to the file. The file column of the article table will store this absolute path.

Customizing the save() method

We observed in the previous section how to save the uploaded file in the edit action. One of the principles of the object oriented programming is the reusability of the code, thanks to its encapsulation in classes. Instead of duplicating the code used to save the file in each action using the ArticleForm form, it is better to move it in the ArticleForm class. Listing 4-27 shows how to override the save() method in order to also save the file and possibly to delete of an existing file.

Listing 4-27 - Overriding the save() Method of the ArticleForm Class

class ArticleForm extends BaseFormPropel
{
  // ...
 
  public function save(PropelPDO $con = null)
  {
    if (file_exists($this->getObject()->getFile()))
    {
      unlink($this->getObject()->getFile());
    }
 
    $file = $this->getValue('file');
    $filename = sha1($file->getOriginalName()).$file->getExtension($file->getOriginalExtension());
    $file->save(sfConfig::get('sf_upload_dir').'/'.$filename);
 
    return parent::save($con);
  }
}

After moving the code to the form, the edit action is identical to the code initially generated by the propel:generate-module task.

class Article extends BaseArticle
{
  public function save(PropelPDO $con = null)
  {
    if (!$this->getSlug())
    {
      $this->setSlugFromTitle();
    }
 
    return parent::save($con);
  }
 
  protected function setSlugFromTitle()
  {
    // ...
  }
}

Customizing the doSave() method

We observed that the saving of an object was made within a transaction in order to guarantee that each operation related to the saving is processed correctly. When overriding the save()method as we did in the previous section in order to save the uploaded file, the executed code is independent from this transaction.

Listing 4-28 shows how to use the doSave() method to insert in the global transaction our code saving the uploaded file.

Listing 4-28 - Overriding the doSave() Method in the ArticleForm Form

class ArticleForm extends BaseFormPropel
{
  // ...
 
  protected function doSave($con = null)
  {
    if (file_exists($this->getObject()->getFile()))
    {
      unlink($this->getObject()->getFile());
    }
 
    $file = $this->getValue('file');
    $filename = sha1($file->getOriginalName()).$file->getExtension($file->getOriginalExtension());
    $file->save(sfConfig::get('sf_upload_dir').'/'.$filename);
 
    return parent::doSave($con);
  }
}

The doSave() method being called in the transaction created by the save() method, if the call to the save() method of the file() object throws an exception, the object will not be saved.

Customizing the updateObject() Method

It is sometimes necessary to modify the object connected to the form between the update and the saving in database.

In our file upload example, instead of storing the absolute path to the uploaded file in the file column, we wish to store the path relative to the sfConfig::get('sf_upload_dir') directory.

Listing 4-29 shows how to override the updateObject() method of the ArticleForm form in order to change the value of the file column after the automatic update object but before it is saved.

Listing 4-29 - Overriding the updateObject() Method and the ArticleForm Class

class ArticleForm extends BaseFormPropel
{
  // ...
 
  public function updateObject($values = null)
  {
    $object = parent::updateObject($values);
 
    $object->setFile(str_replace(sfConfig::get('sf_upload_dir').'/', '', $object->getFile()));
 
    return $object;
  }
}

The updateObject() method is called by the doSave() method before saving the object in database.