Final Code:
[
{{ each blog_article as post sort by post.date desc }}
{
"title": "{{ post.title }}",
"date": "{{ post.date }}",
"image_url": "{{ post.image.getImage() }}",
"id": "{{ post.zid }}"
}{{ if {post._num} != {post._length} }},{{ end-if }}
{{ end-each }}
]