Stash construct works in EE2 but fails in EE3... why? how to fix?

Question

I have this code fragment that works in a template when running EE2, but fails when the same template is run under EE3. I can't work out why. Would value any guidance anyone can give about how to fix. The fragment is:

{exp:stash:category_image parse="yes" trim="yes" output="yes"}
    {exp:category_construct:categories entry_id="{what_we_do_item_selector:image_button_switcher:entry_id}"}
        {if construct:level_count == "1"}
            {exp:channel:categories show="{construct:cat_id}" style="linear"}
                {category_image}
            {/exp:channel:categories}
        {/if}
    {/exp:category_construct:categories}
{/exp:stash:category_image}

which sets a value that is retrieved later within the same template using

{exp:stash:get name="category_image"}

It is a bit messy because category:construct cannot limit its output to a single entry using a tag parameter, and it is difficult to retrieve the category_image for a channel entry.

I am aware that the stash tag uses the 'short form' tag - but weirdly if I replace this with the long form tag, the tag fails in both EE2 and EE3.

This suggests I'm doing something that is probably illegitimate, but I cannot see what it is.

Anyhow - if anyone has any ideas about how I can capture the category_image URL more efficiently I'd be pleased to hear.

Thanks in advance for whatever help you can provide.

For clarity, I'm using EE2.11.3 / EE3.4.6 and Stash 3.0.4

Answer 1

One obvious problem there is that that you are parsing only one layer down when capturing the Stash variable. So you would actually be capturing this:

{exp:channel:categories show="{construct:cat_id}" style="linear"}
   {category_image}
{/exp:channel:categories}

Rather than the value of that tag.

Parse deeper by setting a parse_depth when you set the variable:

{exp:stash:category_image parse="yes" trim="yes" output="yes" parse_depth="2"}
 ...

Other than that it's possible that another tag in your template is malformed and breaking the parser. Try the above on it's own in a template. Turn on template debugging and look for a line beginning Stash: SET category_image ... to verify that the value you want is being captured.