Symfony2 Twig Asset Base_Url是不可预测的？

Question

I'm using a Twig loop to generate <img src=""> for multiple images. My eventual use of this code is to take advantage of a CDN with base_url in the Framework configuration.

Below is the Twig code :

{% for key, mobj in productmedia.getImages %}
    <img src="{{ asset(path('cropImage', {'filename': mobj.getFilename }),'cdn') }}" />
{% endfor %}

{% for key, mobj in productmedia.getImages %}
  <img src="{{ asset(path('cropImageSm', {'filename': mobj.getFilename }),'cdn') }}" />
{% endfor %}

I would expect, at the very least for there to be some consistency in the output.. but it seems SF2 will sometimes use one base_url and sometimes not use one. Why would this be?

Below is the output.

<img src="http://cdn.cloudfront.net/cri/1/matt-skydiving.SH340_SW340.jpg" />
<img src="/cri/1/Swimming.SH340_SW340.jpg" />
<img src="http://cdn.cloudfront.net/cri/1/successman2.SH340_SW340.jpg" />

<img src="/cri/1/matt-skydiving.SH40_SW40.jpg" />
<img src="http://cdn.cloudfront.net/cri/1/Swimming.SH40_SW40.jpg" />
<img src="http://cdn.cloudfront.net/cri/1/successman2.SH40_SW40.jpg" />

As you can see in the first loop.. some inherit the base_url.. and some don't.. I've cleared all cache.. done all the general debugging steps.. It doesn't make sense why this isn't consistent.

Answer 1

You can switch to the url twig function, it's the same as path but this one will always return an absolute url:

url('cropImageSm', {'filename': mobj.getFilename })

Further Reference:

Asset() will use the host supplied in the config.yml

framework:
    templating:
        packages:
            {althostname}:
                base_urls:  { http: ["http://www.domain2.com"], ssl: "/"] }

So {{ asset(path('route1', {'page': 1 }),'althostname') }} would output.. http://www.domain2.com/route1/page/1