Updating object properties in twig

Is there a way to update an object's property in twig?

An object l开发者_Go百科ike the following is passed to twig:

object
   property1
   property2

I would like to update property1 like this:

{% set object.property1 = 'somenewvalue' %}

The above code does not work, but is it possible to do something like this in twig? If not, is there a way to write an extension or macro to do this?

Answer from 2013

You can do it by merging objects:

{% set object = object|merge({'property1': 'somenewvalue'}) %}

Update from 2023

I don’t know from which version of twig this solution does not work anymore. Now you can only create an object with a new name:

{% set data = {foo:1} %}
{% set updated = data|merge({ bar: 2 }) %}

foo: {{ updated.foo }} {# Produces “foo: 1” #}
bar: {{ updated.bar }} {# Produces “bar: 2” #}

Twig has a do tag that allows you to do that.

{% do foo.setBar(value) %}

A possible way to set a property is to create a method in the object which actually creates new properties:

class Get extends StdClass 
  {

    protected function setProperty($name,$value = null)
    {
    $this->$name = $value;
    }

  }

I had the same problem in my knp menu template. I wanted to render an alternate field with the label block, without duplicating it. Of course the underlying object needs an setter for the property.

{%- block nav_label -%}
    {%- set oldLabel = item.label %}
    {%- set navLabel = item.getExtra('nav_label')|default(oldLabel) %}
    {{- item.setLabel(navLabel) ? '' : '' }}
    {{- block('label') -}}
    {{- item.setLabel(oldLabel) ? '' : '' }}
{%- endblock -%}

If your property is array (object->property['key']) you can do something like this:

{% set arr = object.property|merge({"key":['some value']}) %}
{{ set(object, 'property', arr) }}

That equivalent to:

this->property['key'][] = 'some value';

{{ set(object, 'property', value) }}