[Feature Request] If Exists

[shanejones]

We already have this for conditional.

<if condition="foo === 'bar'">
  <p>Foo really is bar! Revolutionary!</p>
</if>

I'm trying to check if a variable exists before outputting it or hiding the block completely if it doesn't exist so I tried

<if condition="foo !== ''">
  <p>Foo really is bar! Revolutionary!</p>
</if>

I think it would be great if we had something like

<if exists="foo">
  <p>Foo really is bar! Revolutionary!</p>
</if>

[cossssmin]

What would exists check for, exactly?

For example, you might check if it's undefined and not show the contents, but that's isn't very reliable since it can be defined as a falsy value (null, false, 0, etc).

I think it's better left to the user to do the check, so one can check for exactly the type they want.

@Scrum?

[Scrum]

Hi, in theory, any value will be converted to boolean at execution

posthtml-expressions/lib/index.js

Line 221 in 77aaf56

let expression = `if (${node.attrs.condition}) { 0 } `

try

<if condition="foo">
  <p>Foo really is bar! Revolutionary!</p>
</if>