Vue-formulate: Add schema v-if support

[timsayshey]

Describe the new feature you'd like

Pretty simple. I just need v-if support in the form schema. ie:

{
  type: 'email',
  label: 'Email',
  vIf: myComputedBool
}

[justin-schroeder]

Howdy @timsayshey,

I thought a lot about conditionals during the development of the package, and it leads to a slippery slope to include it in schema format — so we probably wont include conditionals in the core package, although its a good candidate for a library once hooks are implemented (#135).

However, the schema itself was intentionally designed to be reactive to address this. So the recommended path forward here would be to use something like a computed prop to produce/filter your schema, and then use that computed prop to modify the schema with any additional conditional logic. Good luck!

[gahabeen]

@timsayshey Don't put any conditions in schema, do it when rendering the schema itself. A computed prop is a great idea to push into your array only visible/available elements.

Keep in mind that the generator rest on Vue DOM generator and what I just said above is what Vue team recommends too.

Another similar subject would be to use schema values themselves to hide/show other elements/fields. I might write a plugin for that at some point.