How to get data from the local graph?

问题

I've got the component which displays the hierarchical data. It's a recursive data structure - a hierarchical classifier. Each category in the classifier consists of child categories and so on.

Here's the playground for it:

Relay playground

I've got a component showing this classifier in a third party html form. It is used to pick a category.

At some point in time a user will pick a category from this recursive classifier and I will have to get the full path of data that led to the current level. I mean if a user picks a category at the level 3 of the hierarchy, I must give back these data:

[root cat id, root cat name],
[level 1 cat id, level 1 cat name],
[level 2 cat id, level 2 cat name]

So when I catch the event of picking inside the component at the level 2 how can I get the full path from the root category from Relay store (from local graph)?

回答1:

This has a React solution rather than a Relay one: how to access the path to a given node in the tree? I would synthesize a path, and pass it into your component.

const path = [
  // The elements of the passed-in path.
  ...this.props.path,
  // A new path element using the details from this level.
  [this.props.catId, this.props.catName],
];
<MyNode path={path} onClick={() => alert(path)} />

Click here for a working example.

来源：https://stackoverflow.com/questions/38339060/how-to-get-data-from-the-local-graph