Monkey patch wagtailimages_tags.image tag to resolve specs from a context variable.
Usage:
- Place the patch file into one of your templatetags folder.
- Load the patch after the wagtailimages_tags in your template file.
{% load wagtailimages_tags %}
{% load wagtailimages_tags_patch %}
{% image some_image spec_var as img %}
Quick test:
{% with spec="width-200" %}
{% image some_image spec as img %}
{% endwith %}
Will give you => {% image some_image width-200 as img %}