Twig access object

22
votes

i want to access the value of a object inside a twig template.

Normally i would get the return like that:

echo $lang->get("test");

But how can i do the same in the template with twig?

I tried so many methods but no one worked.

For example i tried:

{{ attribute(lang, get, 'test') }}

with the result

Catchable fatal error: Argument 3 passed to Twig_Node_Expression_GetAttr::__construct() must be an instance of Twig_Node_Expression_Array, instance of Twig_Node_Expression_Constant given

thanks

2
phptwig
Did you try lang.get('test')? – Maerlyn
Yep i did. Wont work aswell. – user1766080
I was here looking for something else but saw your question; I don't know if much has change in the last couple of years of Twig, but for at least the last 5 months since I started using twig, this has worked fine. For example {% for TNS in tnm.getTNservice(user_id) %} {{ TNS.tn_id }} {% for TNP in tnm.getTNpublications(TNS.tn_id) %} {{ TNP.publication_id }} {% endfor %} {% endfor %} – digitaltoast

2 Answers

45
votes

What you're trying to do is call a method on an object with parameters in a Twig template. I do not think this is supported, as it's probably viewed as a bad idea. Twig supports the notion of getters on an object though, which are called without parameters:

{{ lang.test }}

will try to invoke one of the following, in this order:

  • $lang->test
  • $lang->test()
  • $lang->getTest()
  • $lang->isTest()

If the object implements any of these accessors and conventions, Twig will find it. Anything outside of this convention, like get('test'), is not part of the Twig philosophy. And it's not a widely used idiom in general, so you should probably stick to one of the above methods.

See http://twig.sensiolabs.org/doc/templates.html#variables.

You can implement __isset, __get or __call magic methods to support one of these accessor methods.

7
votes

I know this is an old question, but after 3 hours of scouring the internet and finding no examples, I wanted to make sure it got documented.

Going back to one of your original attempts:

{{ attribute(lang, get, 'test') }}

I'm trying to do the same thing, and this should work according to the documentation. Unfortunately, there are no examples of using this. All I found was that the method name (get) had to be a string ('get'), so I changed that, but it still didn't work. What I ended up doing was this:

{% set myText = lang.get('test') %}
{{ myText }}

This worked great, but it's a lot of code to write when I have to do this all over. So I made a simple template with both methods and examined the compiled output. The original was compiled to this:

echo twig_escape_filter($this->env, $this->getAttribute((isset($context["lang"]) ? $context["lang"] : null), "get", "test"), "html", null, true);

and the second (2 liner) to this:

$context["myText"] = $this->getAttribute((isset($context["lang"]) ? $context["lang"] : null), "get", array(0 => "test"), "method");
echo twig_escape_filter($this->env, (isset($context["myText"]) ? $context["myText"] : null), "html", null, true);

After examination, I realized the difference (check the 3rd parameters to getAttribute), the arguments parameter is an array! This is good information to know. I changed my original to this:

{{ attribute(lang, 'get', ['test']) }}

and it's now working!

Hope this helps someone!