{{ someVar | default: "this" }}

[iggyZiggy]

this doesn't work, tried with:
true/false
empty string
null
undefined

results is always empty string

[harttle]

@1.7.9, shopify-liquid applies isTruthy in the default filter. As proposed in #26, isTruthy implementation is compatible with The Ruby Version.

[iggyZiggy]

tried that too, according to ruby version empty string is truthy but in js that's false, so using !!someEmptyStr returns false, and even when set manually to false I still don't get the default value but an empty string

[harttle]

The latest version should resolve this issue, see this jsfiddle: https://jsfiddle.net/su3h56ts/. Now the truthy evaluation for shopify-liquid is documented here.

[iggyZiggy]

Updated to the latest version but still doesn't work, here's the code, variables and logs, maybe it will help

part of the code

    console.log(mailSchedule.html, business.firstName);
    if(!business.firstName)business.firstName=false;
    console.log("firstName:", business.firstName);
    liquid.parseAndRender(mailSchedule.html, business).then(function(liquified){
      console.log("liquified:", liquified);
      mailSchedule.html = liquified;
      finish();
    })

part of the object holding the html variable

html: '<p>hey {{ firstName | default:&#34;test&#34; }}<br/></p>'

output in logs:

<p>hey {{ firstName | default:&#34;test&#34; }}<br/></p>
firstName: false
liquified: <p>hey <br/></p>

[harttle]

Since {{ }} enforces liquid syntax, the " should not be HTML escaped. The following template string should work as you expected.

mailSchedule.html = '<p>hey {{ firstName | default:"test" }}<br/></p>'

{{ firstName | default:"test" }} will trigger a ParseError in Liquid. This exception will be swallowed and empty string will be generated by default. To catch filter exceptions, set the strict_filters option.

[iggyZiggy]

I've seen here that unescape and escape functions exists, figured it's already applied to whole string. Can that function/filter be called just on that part or do i need to make some kind of pre-parser/workaround before feeding liquid with it?
It would make my life a lot easier if i wouldn't need to parse content inside of {{ }} considering liquid already has a way to do it.

[harttle]

Can that function/filter be called just on that part

No. Filter functionalities only apply to values of context variables, not the filter syntax itself.

Unescape HTML is quite easy, but {{ firstName | default:"test" }} is just not valid in Liquid syntax.