Documentation of v-with about discussion HOT 5 OPEN

I think the doc stated elsewhere that all child VMs automatically have access to parent data in their templates. However, they are not really inheriting it, because they cannot manipulate them in javascript as this.someProp. v-with specifically inherits the data so the child VM can manipulate them on itself.

Unnamed v-with means the child is inheriting target object as its $data - since each vm can only have one root $data object, there can be only one such binding.

Binding stuff with the same name was tricky when I was implementing it, so it's likely there are still some bugs lying around. Would appreciate it if you can make a fiddle for the mentioned behavior.

from discussion.

@yyx990803 Thanks for folllowing up.

Yes, you are right you can't manipulate the data directly within the component, but it is available as if it was within the template code though.

I've made a very simple fiddle for that last item as requested.

http://jsfiddle.net/doginthehat/yvBD8/

The donkey watch event triggers twice (cf. console). If you take out the v-with, it triggers once.

from discussion.

ps. The thought process behind doing that was a combination of the initial reported feedback on the docs.

1. I thought that you had to explicitly pass data with v-with
2. I needed to pass multiple properties to the components
3. I didn't want to invent new names for these properties within the component

And this led to the situation reported as demonstrated in the fiddle (with events firing multiple times).

Hope this helps.

from discussion.

@yyx990803
v-with substitute child $data with parent $data, is that so?
How can a child component access $data from parent, but mantain its won data?
Thanks!

from discussion.

When you use it like v-with="obj", the child's $data will be replaced. However when you use v-with="childKey: parentKey" it will attach the parent property to the child's $data as childKey.

from discussion.