Version

Documentation » Admin

19. The breadcrumbs builder »

« 17. Console/Command-Line Commands

18. Troubleshooting

Note

This article assumes you are using Symfony 4. Using Symfony 2.8 or 3 will require to slightly modify some namespaces and paths when creating entities and admins.

18.1. The toString method

Sometimes the bundle needs to display your model objects, in order to do it, objects are converted to string by using the __toString magic method. Take care to never return anything else than a string in this method. For example, if your method looks like that:

<?php
// src/Entity/Post.php

class Post
{
    // ...

    public function __toString()
    {
        return $this->getTitle();
    }

    // ...
}

You cannot be sure your object will always have a title when the bundle will want to convert it to a string. So in order to avoid any fatal error, you must return an empty string (or anything you prefer) for when the title is missing, like this:

<?php
// src/Entity/Post.php

class Post
{
    // ...

    public function __toString()
    {
        return $this->getTitle() ?: '';
    }

    // ...
}

18.2. Large filters and long URLs problem

If you will try to add hundreds of filters to a single admin class, you will get a problem - very long generated filter form URL. In most cases you will get server response like Error 400 Bad Request OR Error 414 Request-URI Too Long. According to a StackOverflow discussion “safe” URL length is just around 2000 characters. You can fix this issue by adding a simple JQuery piece of code on your edit template :

$(function() {
    // Add class 'had-value-on-load' to inputs/selects with values.
    $(".sonata-filter-form input").add(".sonata-filter-form select").each(function(){
        if($(this).val()) {
            $(this).addClass('had-value-on-load');
        }
    });

    // REMOVE ALL EMPTY INPUT FROM FILTER FORM (except inputs, which has class 'had-value-on-load')
    $(".sonata-filter-form").submit(function() {
        $(".sonata-filter-form input").add(".sonata-filter-form select").each(function(){
            if(!$(this).val() && !$(this).hasClass('had-value-on-load')) {
                $(this).remove()
            };
        });
    });
});

Found a typo? Something is wrong in this documentation? Just fork and edit it!