Código del controladorsrc/Controller/SecurityController.php at line 33

public function login(Request $request, AuthenticationUtils $helper): Response
{
    // if user is already logged in, don't display the login page again
    if ($this->getUser()) {
        return $this->redirectToRoute('blog_index');
    }

    // this statement solves an edge-case: if you change the locale in the login
    // page, after a successful login you are redirected to a page in the previous
    // locale. This code regenerates the referrer URL whenever the login page is
    // browsed, to ensure that its locale is always the current one.
    $this->saveTargetPath($request->getSession(), 'main', $this->generateUrl('admin_index'));

    return $this->render('security/login.html.twig', [
        // last username entered by the user (if any)
        'last_username' => $helper->getLastUsername(),
        // last authentication error (if any)
        'error' => $helper->getLastAuthenticationError(),
    ]);
}

Código de la plantilla Twigtemplates/security/login.html.twig at line 1

{% extends 'base.html.twig' %}

{% block body_id 'login' %}

{% block javascripts %}
    {{ parent() }}
    {{ encore_entry_script_tags('login') }}
{% endblock %}

{% block main %}
    {% if error %}
        <div class="alert alert-danger">
            {{ error.messageKey|trans(error.messageData, 'security') }}
        </div>
    {% endif %}

    <div class="row">
        <div class="col-sm-5">
            <div class="well">
                <form action="{{ path('security_login') }}" method="post">
                    <fieldset>
                        <legend><i class="fa fa-lock" aria-hidden="true"></i> {{ 'title.login'|trans }}</legend>
                        <div class="form-group">
                            <label for="username">{{ 'label.username'|trans }}</label>
                            <input type="text" id="username" name="_username" value="{{ last_username }}" class="form-control"/>
                        </div>
                        <div class="form-group">
                            <label for="password">{{ 'label.password'|trans }}</label>
                            <input type="password" id="password" name="_password" class="form-control" />
                        </div>
                        <input type="hidden" name="_target_path" value="{{ app.request.get('redirect_to') }}"/>
                        <input type="hidden" name="_csrf_token" value="{{ csrf_token('authenticate') }}"/>
                        <button type="submit" class="btn btn-primary">
                            <i class="fa fa-sign-in" aria-hidden="true"></i> {{ 'action.sign_in'|trans }}
                        </button>
                    </fieldset>
                </form>
            </div>
        </div>

        <div id="login-help" class="col-sm-7">
            <h3>
                <i class="hidden-xs fa fa-long-arrow-left" aria-hidden="true"></i>
                {{ 'help.login_users'|trans }}
            </h3>

            <table class="table table-striped table-bordered table-hover">
                <thead>
                    <tr>
                        <th scope="col">{{ 'label.username'|trans }}</th>
                        <th scope="col">{{ 'label.password'|trans }}</th>
                        <th scope="col">{{ 'label.role'|trans }}</th>
                    </tr>
                </thead>
                <tbody>
                    <tr>
                        <td>john_user</td>
                        <td>kitten</td>
                        <td><code>ROLE_USER</code> ({{ 'help.role_user'|trans }})</td>
                    </tr>
                    <tr>
                        <td>jane_admin</td>
                        <td>kitten</td>
                        <td><code>ROLE_ADMIN</code> ({{ 'help.role_admin'|trans }})</td>
                    </tr>
                </tbody>
            </table>

            <div id="login-users-help" class="panel panel-default">
                <div class="panel-body">
                    <p>
                        <span class="label label-success">{{ 'note'|trans }}</span>
                        {{ 'help.reload_fixtures'|trans }}<br/>

                        <code class="console">$ php bin/console doctrine:fixtures:load</code>
                    </p>

                    <p>
                        <span class="label label-success">{{ 'tip'|trans }}</span>
                        {{ 'help.add_user'|trans }}<br/>

                        <code class="console">$ php bin/console app:add-user</code>
                    </p>
                </div>
            </div>
        </div>
    </div>
{% endblock %}

{% block sidebar %}
    {{ parent() }}

    {{ show_source_code(_self) }}
{% endblock %}