Question

How i can wrap every block code with spaceless to crop whitespaces from my twig/html

for example now i have:

{% block content %}

    <div class="box clearfix clearall">
        <div class="ct colcontainer">
            <div class="col-1">
                <div class="chars">
                    <table class="layout data-char">
                        <thead>

blabla

{% endblock %}

And when symfony try to render it, i want that symfony saw

{% block content %}
{% spaceless %}
    <div class="box clearfix clearall">
        <div class="ct colcontainer">
            <div class="col-1">
                <div class="chars">
                    <table class="layout data-char">
                        <thead>

blabla
{% endspaceless %}
{% endblock %}

Answer 1

Define a custom Twig tag (the copy-and-paste way)

You can define a custom Twig tag spacelessblock which combines block and spaceless. Then you can use {% spacelessblock xyz %}…{% endspacelessblock %} in your templates. Here is how you do it the quick and dirty (copy and paste) way.

A new Twig node

First, define a class Twig_Node_SpacelessBlock (e.g. in the Extension directory of your bundle):

class Twig_Node_SpacelessBlock extends \Twig_Node_Block
{
    public function __construct($name, Twig_NodeInterface $body, $lineno, $tag = null)
    {
        parent::__construct(array('body' => $body), array('name' => $name), $lineno, $tag);
    }

    public function compile(Twig_Compiler $compiler)
    {
        // top part of Block.compile
        $compiler
            ->addDebugInfo($this)
            ->write(sprintf("public function block_%s(\$context, array \$blocks = array())\n", $this->getAttribute('name')), "{\n")
            ->indent()
        ;

        // the content of the body is treated like in Spaceless.compile
        $compiler
            ->write("ob_start();\n")
            ->subcompile($this->getNode('body'))
            ->write("echo trim(preg_replace('/>\s+</', '><', ob_get_clean()));\n")
        ;

        // bottom part of Block.compile
        $compiler
            ->outdent()
            ->write("}\n\n")
        ;
    }
}

A new Twig token parser

Our new Twig node needs to be built somewhere whenever Twig finds a {% spacelessblock xyz %} in a template. For that, we need a token parser which we call Twig_TokenParser_SpacelessBlock. We basically copy and paste Twig_TokenParser_Block:

class Twig_TokenParser_SpacelessBlock extends \Twig_TokenParser
{
    public function parse(Twig_Token $token)
    {
        // …
        $this->parser->setBlock($name, $block = new Twig_Node_SpacelessBlock($name, new Twig_Node(array()), $lineno));
        // …
    }

    public function decideBlockEnd(Twig_Token $token)
    {
        return $token->test('endspacelessblock');
    }

    public function getTag()
    {
        return 'spacelessblock';
    }
}

Tell Twig about it

In your extension class:

class Extension extends \Twig_Extension
{
    public function getTokenParsers()
    {
        return array(
            new Twig_TokenParser_SpacelessBlock(),
        );
    }
}

Tell Symfony about it

If not already done, add the following to your your services.yml:

services:
    # …
    my.extension:
        class:     Acme\MyBundle\Extension\Extension
        tags:
          - { name: twig.extension }

Better alternatives

Preprocessor

A better way would be to use a preprocessor to simply replace

{% spacelessblock xyz %}
…
{% endspacelessblock %}

by

{% block xyz %}{% spaceless %}
…
{% endspaceless %}{% endblock %}

which reuses all the code that already has been written in the Twig project, including possible changes.