Problem with injecting stash pipe separated entry_ids into channel entries loop when no results

Question

I've came across a problem today where I wanted to 'inject' a stash pipe separated list of entry_ids into the entry_id parameter of a channel entries loop.

The problem wasn't to do with stash as such. I'd got my parse order correct, and stash was doing it's job as expected. The problem was that when my stash variable didn't contain any entry_ids, the channel_entries loop just output the latest entries in that channel rather than output nothing.

Here's my initial code that didn't do what I wanted:

{exp:stash:set name="recently_viewed_ids" output="no" parse_tags="yes" trim="yes"}
{exp:channel:entries channel="properties" disable="categories|member_data|pagination|trackbacks" dynamic="no" backspace="1"}{entry_id}|{/exp:channel:entries}
{/exp:stash:set}

and the channel entries loop that used the stash variable:

{exp:channel:entries 
    channel="properties"
    entry_id="{exp:stash:get name='recently_viewed_ids'}"
    limit="4"
    disable="categories|member_data|pagination|trackbacks" 
    parse="inward"
}
{!-- display custom fields here --}
{/exp:channel:entries}

So even if recently_viewed_ids was empty, EE returned the 4 latest entries in the channel, rather than nothing.

So what's the way around this?

Jim

Answer 1

After much searching and head scratching I finally turned to Twitter and got help from the fabulous @mediagirl and @low.

The solution to this is fairly simple:

To trigger a 'no_results' situation in the channel_entries loop using the entry_id parameter we have to enter either "-1" or "0|":

entry_id = "0|"

In my case I used "0|" and actually fixed_order instead of entry_id to preserve the order that the entry_ids are in.

So my final working code now looks like this:

{exp:channel:entries 
    channel="properties"
    fixed_order="0|{exp:stash:get name='recently_viewed_ids'}"
    limit="4"
    disable="categories|member_data|pagination|trackbacks" 
    parse="inward"
}
    {!-- display custom fields here --}
{/exp:channel:entries}

I hope that this manages to help someone else.

Incidentally, I should add that I'm using the JP Recently Viewed extension, so my original channel_entries loop also contains recently_viewed="y".

Cheers

Jim