Conditionally set a Stash value

Question

I'm using Stash to set a value like so;

{exp:stash:set_value name="head_title" value="{title}"}

However, I have now added a new channel field {news_meta_title} and would like to pass this as the value of "head_title" if it has been entered, otherwise just use {title}.

I have tried doing this, but it didn't work;

{if news_meta_title}
    {exp:stash:set_value name="head_title" value="{news_meta_title}"}
{if:else}
    {exp:stash:set_value name="head_title" value="{title"}
{/if}

I was wondering if anyone had any pointers?

I know that it's all down to parse order, but not sure on how to resolve this.

Answer 1

There is in fact a default="" parameter available for Stash set, however it only comes into play if you define a match parameter to test the value being set against a regular expression:

Thus this will do what you want:

{exp:stash:set name="head_title" match="#^\S+#" default="{title}"}{news_meta_title}{/exp:stash:set}

One problem with this approach however is that if you pass a variable as a default value (e.g. {title}) - and that value contains double quotes - that will blow up the parameters and throw a template parse error.

Switchee provides a simple way around this problem because you can pass a reference to the Stash variable to evaluate (rather than the variable value itself) by prefixing the name with stash:

{exp:stash:set name="head_title"}{news_meta_title}{/exp:stash:set}

{exp:switchee variable="stash:head_title" parse="inward"}
    {case value=""}
        {exp:stash:set name="head_title"}{title}{/exp:stash:set}
    {/case}
{/exp:switchee}

Alternatively, blocks allow you to provide a fallback value when you get the variable - this can be useful if alternative markup is required when the default value is used:

For example:

{exp:stash:set name="head_title"}{news_meta_title}{/exp:stash:set}
{exp:stash:set name="entry_title"}{title}{/exp:stash:set}

{exp:stash:block name="head_title"}
    {!-- fallback value if "head_title" is empty --}
    {exp:stash:entry_title}
{/exp:stash:block}

Answer 2

I guess you could wrap that whole block with {exp:stash:parse process="end"} ... {/exp:stash:parse} to make it all parse at the end. Like this

{exp:stash:parse process="end"}
    {if news_meta_title}
        {exp:stash:set_value name="head_title" value="{news_meta_title}"}
    {if:else}
        {exp:stash:set_value name="head_title" value="{title"}
    {/if}
{/exp:stash:parse}

Mark's docs are here.

Answer 3

I think this might be due to using an advanced conditional, which I guess could result in parse order issues.

Maybe this would work:

{if news_meta_title}
    {exp:stash:set_value name="head_title" value="{news_meta_title}"}
{/if}
{if news_meta_title == ""}
    {exp:stash:set_value name="head_title" value="{title}"}
{/if}

If not, have you tried adding parse="inward" as Mark mentions in the documentation?

Alternatively, you could try this set-up instead, which works for me:

{exp:stash:set name="head_title" parse_conditionals="yes"}
    {if news_meta_title}
      {news_meta_title}
    {/if}
    {if news_meta_title == ""}
       {title}
    {/if}
{exp:stash:set}