Laravel - Blade comments , blade rendering causing page to crash

Question

I'm rendering a page that is primarily a form with view::make in Laravel and it is crashing, causing ERR_CONNECTION_RESET. After a long investigation and many red herrings, I started erasing (not commenting) random sections out of the blade file for the view and realized that if I

a) erase 2 of the {{Form}} calls inside this section of the form

b) remove the {{-- and --}} from around this section of the form

    {{--
    <div class="form-row">
      {{ Form::label('foo', 'foo:') }}
      {{ Form::text('foo') }}
    </div>
    <div class="form-row">
      {{ Form::label('foo', 'foo:') }}
      {{ Form::text('foo') }}
    </div>
    <div class="form-row">
      {{ Form::label('foo', 'foo') }}
      {{ Form::text('foo') }}
    </div>
    --}}

the page will render. I am not sure what exactly the cause here is. There are other blocks above and below, although this is a 3-div commented out section which none of the others are.

Anyone have a clue what is causing this? Running on WAMP if that matters.

Answer 1

Note: this answer was given for Laravel 4.2, but should still apply. There are some special cases of Blade compilation issues that are dependent on the version of Laravel and/or PHP, so it's best to only use Blade comments for the simplest use-cases.

The solution is to only use Blade comments for simple remarks, or to comment out single-line Blade functions. Do not nest Blade/PHP code inside of Blade comments. Use standard PHP block comments to comment out multiple lines of code within a single comment (PHP, HTML, multiple blade functions, etc.).

---

Valid Blade Comments:

Single Blade Function:

{{-- Form::text('foo') --}}

Remark:

{{-- Form Section 1 --}}

---

Invalid Blade Comments:

Incorrect syntax:

{{-- Form::text('foo') --  }} 

"@" Inside of Blade comment

{{-- @Form::text('foo') --}} 

Nested PHP:

{{-- <?php 
echo "foo";
echo "bar
?> --}} 

Nested Blade:

{{-- 
{{ HTML::form("foo") }};
{{ HTML::form("bar") }};
--}} 

---

Use PHP Block Comments instead. They are still usable in a blade.php file

<?php /* 
{{ HTML::form("foo") }};
{{ HTML::form("bar") }};
*/ ?> 

---

Alternatively, comment out your Blade one line at a time:

{{-- HTML::form("foo") --}};
{{-- HTML::form("bar") --}};

---

Internals:

For the OP's code, Laravel's Blade Compiler will generate a temporary PHP file containing the following PHP/HTML:

<?php /* 
    <div class="form-row">
      <?php echo Form::label('foo', 'foo:'); ?>

<?php echo Form::text('foo'); ?>

</div>
<div class="form-row">
    <?php echo Form::label('foo', 'foo:'); ?>

    <?php echo Form::text('foo'); ?>

</div>
<div class="form-row">
    <?php echo Form::label('foo', 'foo'); ?>

    <?php echo Form::text('foo'); ?>

</div>
*/ ?>

The Blade inside of your Blade comments are still being parsed into PHP. The PHP end tags inside of the PHP block-comment is causing the Apache's parser to end early, resulting in some badly-formed PHP/HTML that could be crashing your connection (likely caused by the dangling */ ?>).

?> breaks out of PHP mode and returns to HTML mode, and // or # cannot influence that.

Using any of the aforementioned invalid Blade comments will cause similar compilation issues. Avoid Blade comments for anything other than remarks or commenting Blade functions out one line at a time.