c. Secure the updating request with a transaction save() method is a good opportunity to illustrate the implementation of transactions in symfony. Replace the code by:

d. Change the template the ->getInterestedUsers() method of the Question object works properly, it is time to simplify the _interested_user.php fragment by replacing: <?php echo count($question->getInterests()) ?> By <?php echo $question->getInterestedUsers() ?> e. Test the validity of the modification Run again the data import batch: $ cd /home/sfprojects/askeet/batch $ php load_data.php When creating the records of the Interest table, the sfPropelData object will use the overridden save() method and should properly update the related User records. Check it by requesting the home page and the detail of the first question: http://askeet/frontend_dev.php/ http://askeet/frontend_dev.php/question/show/id/XX f. 5.

b. Modify the Save() method of the Interest object Open the askeet/lib/model/Interest.php file and write in the following method: public function save($con = null) {

   $ret = parent::save($con);

   // update interested_users in question table
   $question = $this->getQuestion();
   $interested_users = $question->getInterestedUsers();
   $question->setInterestedUsers($interested_users   1);
   $question->save($con);
   return $ret;

}The new save() method gets the question related to the current interest, and increments its interested_users field. Then, it does the usual save(), but because a $this->save(); would end up in an infinite loop, it uses the class method parent::save() instead.

4. Modify the question Part II The $question->getInterests() call of the new fragment does a request to the database and returns an array of objects of class Interest. This is a heavy request for just a number of interested persons, and it might load the database too much. Remember that this call is also done in the listSuccess.php template, but this time in a loop, for each question of the list. It would be a good idea to optimize it. One good solution is to add a column to the Question table called interested_users, and to update this column each time an interest about the question is created. a. Add a field to the User object model Modify the askeet/config/schema.xml data model by adding to the ask_question table: <column name="interested_users" type="integer" default="0" /> Then rebuild the model: $ symfony propel-build-model We also need to update the actual database. To avoid writing some SQL statement, We should rebuild SQL schema and reload test data: $ symfony propel-build-sql $ mysql -u youruser -p askeet < data/sql/lib.model.schema.sql $ php batch/load_data.php  Note: There is more than way to do it. Instead of rebuilding the database, you can add the new column to the MySQL table by hand: $ mysql -u youruser -p askeet -e "alter table ask_question add interested_users int default '0'"

3. Don’t Repeat yourself One of the good principles of agile development is to avoid duplicating code.We probably noticed some duplicated code between the listSuccess.php template and the showSuccess.php template

 <div class="interested_mark" id="mark_<?php echo $question->getId() ?>">
   <?php echo count($question->getInterests()) ?>

</div> Create an _interested_user.php file in the askeet/apps/frontend/modules/question/templates/ directory with the following code: <div class="interested_mark" id="mark_<?php echo $question->getId() ?>">

 <?php echo count($question->getInterests()) ?>

</div> Then, replace the original code in both templates (listSuccess.php and showSuccess.php) with:

 <?php include_partial('interested_user', array('question' => $question)) ?>