A problem with {% elseif %} statement

Question

Here is my situation. This is not a whole code, only the part, where I'm having a problem. At the back end, model coverbackup is populated with files as well as model cover. If I depopulate cover (remove image from entry), I want to load model coverbackup. I was checking over and over, If I got to my file in matrix field correctly, but It seems I have.

Than I've tried to check if elseif statement loads anything on cover=false, I got empty output.

{# Get the slides stored in variable "slides" #}
{% set slides = craft.entries.section('handle').type(['article', 'blog', 'news']).order('RAND()').limit(3) %}

    {% if slides %}
    <ul class="uk-slideshow">

        {% for slide in slides %}  
        <li>

            {% set cover = slide.coverImage %}
            {% set coverbackup = slide.entryContent %}

                    {% if cover %}    
                        {% for cover in cover %}
                            <div class="uk-panel-teaser">
                                <img class="uk-margin-bottom" src="{{ cover.getUrl('thumb700') }}" alt="{{ cover.title }}">
                            </div>
                        {% endfor %}


                    {% elseif coverbackup %}
                        {% for block in coverbackup %}
                            {% if block.type == "image" %}
                                {% for image in block.images %}
                                    <div class="uk-panel-teaser">
                                        <img class="uk-margin-bottom" src="{{ image.getUrl('thumb700') }}" alt="{{ image.title }}">
                                    </div>
                                {% endfor %}
                            {% endif %}
                        {% endfor %}
                    {% endif %}

      </li>
     {% endfor %}

</ul>
{% endif %}

Answer 1

The proper conditional statement in this case would be to test for the length property of your Asset field, i.e. cover:

{% if cover | length %}

The reason this works, is that calling slide.coverImage will – as long as the attribute "coverImage" exists for the "slide" model – never return a falsey value, even if there are no files. It will in fact always return an instance of the ElementCriteriaModel class, i.e. an object representing your Asset field.

What the conditional {% if cover | length %} does is to read the length property of the ElementCriteriaModel object. The length property will represent the number of images in the Asset field – if it contains 0 images, the conditional will evaluate to "false" – as the number 0 within a conditional is interpreted as a falsey value. If you prefer, you can also write the statement like this:

{% if cover | length > 0 %}