manualy clear application cache -
remove all files in /app/cache:
`rm -r app/cache/*`


and then warmup cache for needed environment like that:

`app/console cache:warmup --env=prod`


When I try to run the command:

    import psycopg2

I get the error:

    ImportError: dlopen(/Users/gwulfs/anaconda/lib/python2.7/site-packages/psycopg2/_psycopg.so, 2): Library not loaded: libssl.1.0.0.dylib
      Referenced from: /Users/gwulfs/anaconda/lib/python2.7/site-packages/psycopg2/_psycopg.so
      Reason: image not found

So far I have tried `brew install openssl` and have referenced (with no luck):

https://stackoverflow.com/questions/11365619/psycopg2-installation-error-library-not-loaded-libssl-dylib

http://joshuakehn.com/2013/10/13/Postgresapp-and-psycopg2-on-OS-X.html

https://stackoverflow.com/questions/16407995/psycopg2-image-not-found

Import psycopg2 Library not loaded: libssl.1.0.0.dylib

Can I add `null` values to an `ArrayList` even if it has a generic type parameter?

Eg.

    ArrayList&lt;Item&gt; itemList = new ArrayList&lt;Item&gt;();
    itemList.add(null);

If so, will

    itemsList.size();

return 1 or 0?


If I can add `null` values to an `ArrayList`, can I loop through only the indexes that contain items like this?

    for(Item i : itemList) {
       //code here
    }

Or would the for each loop also loop through the null values in the list?


    

Adding null values to arraylist

After updating Symfony with Composer to version 2.6 it gives this error:

&gt; [Symfony\Component\DependencyInjection\Exception\InvalidArgumentException] The parameter &quot;debug.error_handler.throw_at&quot; must be defined.



&#39;The parameter &quot;debug.error_handler.throw_at&quot; must be defined&#39; error after updating to Symfony 2.6

<p>After updating Symfony with Composer to version 2.6 it gives this error:</p>
<p>> [Symfony\Component\DependencyInjection\Exception\InvalidArgumentException] The parameter "debug.error_handler.throw_at" must be defined.</p>


I tried to gather some information about the following way to delete automatically child entity when a parent entity is deleted. Seems that the most common way is to use one those three annotation: `cascade={&quot;remove&quot;}` OR `orphanRemoval=true` OR `ondelete=&quot;CASCADE&quot;`. 

 I am a bit confused about the third one: `ondelete=&quot;CASCADE&quot;`, as the explanation in doctrine official documentation about this one are very scarce) and I would love if someone could **confirm me the following information** I gathered and understand from my research on the net and experience...   

What does it do?

`cascade={&quot;remove&quot;}`
==&gt; the entity on the inverse side is deleted when the owning side entity is. Even if you are in a `ManyToMany` with other owning side entity.   
- should be used on collection (so in `OneToMany` or `ManyToMany` relationship)  
- implementation in the ORM

`orphanRemoval=true`
==&gt; the entity on the inverse side is deleted when the owning side entity is AND it is not connected to any other owning side entity anymore. (ref.  [doctrine official_doc](http://doctrine-orm.readthedocs.org/en/latest/reference/xml-mapping.html?highlight=orphanremoval#defining-many-to-one-associations)
- implementation in the ORM   
- can be used with `OneToOne`, `OneToMany` or `ManyToMany`

`onDelete=&quot;CASCADE&quot;` 
==&gt; this will add On Delete Cascade to the foreign key column in the database  
- This strategy is a bit tricky to get right but can be very powerful and fast. (ref.  [doctrine official_doc](http://doctrine-orm.readthedocs.org/en/latest/reference/working-with-objects.html?highlight=tricky#removing-entities) ... but haven&#39;t read more explanations)   
- ORM has to do less work (compared to the two previous ways of doing it) and therefore should have better performance.

**other information**   
- all those 3 ways of doing are implemented on bidirectional relationship entities (**_right???_**)    
- using `cascade={&quot;remove&quot;}` completely by-passes any foreign key onDelete=CASCADE. (ref. [doctrine_official_doc](http://doctrine-orm.readthedocs.org/en/latest/reference/working-with-objects.html?highlight=tricky#removing-entities))


EXAMPLE ON HOW TO USE IT IN CODE
--
- `orphanRemoval` and `cascade={&quot;remove&quot;}` are defined in the inversed entity class.  
- `ondelete=&quot;CASCADE&quot;` is defined in the owner entity
- you can also just write `@ORM\JoinColumn(onDelete=&quot;CASCADE&quot;)` and let doctrine handle the column names

**cascade={&quot;remove&quot;}**

    /**
    * @OneToMany(targetEntity=&quot;Phonenumber&quot;, mappedBy=&quot;contact&quot;, cascade={&quot;remove&quot;})
    */
    protected $Phonenumbers

 
**orphanRemoval=true**

    /**
    * @OneToMany(targetEntity=&quot;Phonenumber&quot;, mappedBy=&quot;contact&quot;, orphanRemoval=true)
    */
    protected $Phonenumbers

**onDelete=&quot;CASCADE&quot;**

    /** 
    * @ManyToOne(targetEntity=&quot;Contact&quot;, inversedBy=&quot;phonenumbers&quot;)
    * @JoinColumn(name=&quot;contact_id&quot;, referencedColumnName=&quot;contact_id&quot;, onDelete=&quot;CASCADE&quot;)
    */ 
    protected $contact; 



cascade={&quot;remove&quot;} VS orphanRemoval=true VS ondelete=&quot;CASCADE

I set up a parameter as array, as described in [http://jmsyst.com/libs/serializer/master/reference/annotations][1]

    class QuestionAnswer
    {
        /**
       * @JMS\Type(&quot;ArrayCollection&lt;Rest\Bundle\Entity\Fixture\QuestionOptions&gt;&quot;)
         * @Groups({&quot;QuestionAnswer&quot;})
       */
          public $question_options_array ;
    }

 and define some options in another class

    class QuestionOptions
    {
        /**
           * @JMS\Type(&quot;integer&quot;)
           * @Groups({&quot;get_option&quot;})
           */
          public $question_option_id ;
    
          /**
           * @JMS\Type(&quot;string&quot;)
           * @Groups({&quot;post_option&quot;})
           */
          public $question_option_description;
    }
In @ApiDoc I define 
    

         * input={
         *      &quot;class&quot; = &quot;Rest\BeautyBundle\Entity\Fixture\ProfileQuestionAnswer&quot;, 
         *      &quot;groups&quot;={&quot;QuestionAnswer&quot;, &quot;get_option&quot;},
         *  },
Before updating it works well. But after `composer update` only the &quot;QuestionAnswer&quot; group name works and it shows all properties from QuestionOptions class.
How can I submit properties in the array the way it was before the update?

  [1]: http://jmsyst.com/libs/serializer/master/reference/annotations

Group exclusion in Nelmio Api Doc does not work After updating composer

I am deploying a Laravel barebone project to Microsoft Azure, but whenever I try to execute `php artisan migrate` I get the error:

&gt;[2015-06-13 14:34:05] production.ERROR: exception &#39;Symfony\Component\Debug\Exception\FatalErrorException&#39; with message &#39;Class &#39;&#39; not found&#39; in D:\home\site\vendor\laravel\framework\src\Illuminate\Database\Migrations\Migrator.php:328

Stack trace:

     #0 {main}  

What could be the problem? Thank you very much

### -- edit --

**Migration Class**

    &lt;?php
    use Illuminate\Database\Schema\Blueprint;
    use Illuminate\Database\Migrations\Migration;

    class CreateUsersTable extends Migration {

        /**
         * Run the migrations.
         *
         * @return void
         */
        public function up()
        {
            Schema::create(&#39;users&#39;, function(Blueprint $table)
            {
                $table-&gt;bigIncrements(&#39;id&#39;);
                $table-&gt;string(&#39;name&#39;, 50);
                $table-&gt;string(&#39;surname&#39;, 50);
                $table-&gt;bigInteger(&#39;telephone&#39;);
                $table-&gt;string(&#39;email&#39;, 50)-&gt;unique();
                $table-&gt;string(&#39;username&#39;, 50)-&gt;unique();
                $table-&gt;string(&#39;password&#39;, 50);
                $table-&gt;boolean(&#39;active&#39;)-&gt;default(FALSE);
                $table-&gt;string(&#39;email_confirmation_code&#39;, 6);
                $table-&gt;enum(&#39;notify&#39;, [&#39;y&#39;, &#39;n&#39;])-&gt;default(&#39;y&#39;);
                $table-&gt;rememberToken();
                $table-&gt;timestamps();
                
                $table-&gt;index(&#39;username&#39;);
            });
        }

        /**
         * Reverse the migrations.
         *
         * @return void
         */
        public function down()
        {
            Schema::drop(&#39;users&#39;);
        }
    }

Laravel migrations: Class &quot;not found&quot;

I&#39;m doing a program using Slim 2 that uses Twig as my templating engine. so It uses the syntax `{{ foo }}` in php file. On the other hand, I&#39;m using vue.js, it also uses `{{ bar }}`. 

E.g.

I&#39;m gonna do the two way binding, below is my html code.

    &lt;div class=&quot;container&quot;&gt;
        Label Value: &lt;label&gt;{{ foo }}&lt;/label&gt;&lt;br&gt;
        Field Value: &lt;input v-model=&quot;foo&quot;&gt;
    &lt;/div&gt;

and here is my vue js code.

    new Vue({
    
        el: &#39;.container&#39;,
        data: {
            foo: &#39;Hello world.&#39;
        }
    });

So the Hello world should be in the Label Value.

The output is the image below.

![enter image description here][1]


Which it did not worked, probably the system thought it&#39;s a twig variable. So I checked by passing variable in a view.

    $app-&gt;get(&#39;/&#39;, function() use ($app) {
        $app-&gt;render(&#39;login.php&#39;, [
            &#39;foo&#39; =&gt; &#39;FROM PHP FILE&#39;
        ]);
    })-&gt;name(&#39;login&#39;);

So I checked, the Label Value: shows the variable that I passed from the PHP file not on the VUE code.

Kind of hard to explain but you get the point. Was wondering how to bypass twig&#39;s template and use the `{{  }}` from vue also.

![enter image description here][2]


  [1]: http://i.stack.imgur.com/JUeMX.png
  [2]: http://i.stack.imgur.com/7htgU.png

Conflict on Template of Twig and Vue.js

When trying to run a migration I get the error Artisan migration 

&gt; error:`Class &#39;Doctrine\\DBAL\\Driver\\PDOMySql\\Driver&#39; not found`

I have read the questions here and also see the notes to add:

`doctrine/dbal&quot;: &quot;~2.3` in the requires section of composer.json

[Github Bug Report][1]

However, I don&#39;t understand what has happened. I created table a few days ago with no issue.

I can&#39;t figure out what to do after adding that dependency in composer.son.

I don&#39;t want to accidentally update any other packages.


  [1]: https://github.com/laravel/framework/issues/3116

Content Type	Original Author	Original Content on Stackoverflow
Question	Alex Belyaev	View Question on Stackoverflow
Solution 1 - Symfony	Alex Belyaev	View Answer on Stackoverflow

'The parameter "debug.error_handler.throw_at" must be defined' error after updating to Symfony 2.6

Symfony Problem Overview

Symfony Solutions

Solution 1 - Symfony

Adding null values to arraylist

Import psycopg2 Library not loaded: libssl.1.0.0.dylib

Attributions