Keystone.js nested categories - keystonejs

Question

I am trying to implement nested categories for Post model.
What I have:
Post.add({
title: { type: String, required: true },
state: { type: Types.Select, options: 'draft, published, archived', default: 'draft', index: true },
author: { type: Types.Relationship, ref: 'User', index: true },
publishedDate: { type: Types.Date, index: true, dependsOn: { state: 'published' } },
content: {
extended: { type: Types.Html, wysiwyg: true, height: 300 },
},
categories: { type: Types.Relationship, ref: 'PostCategory', index: true }
});
And category
PostCategory.add({
name: { type: String, required: true },
subCategories: { type: Types.TextArray }
});
Now I can add a list of subcategories to each category.
What I can't do is to display subcategories while creating a post. Also if I change category I need to load sub categories related to selected category.
My plan was to achieve that with watch functionality but it seems only works on save.
Another thing I was thinking about was to add subcategories as relationship, see ref:
categories: { type: Types.Relationship, ref: 'PostCategory.subCategories', index: true }
But it isn't working as well.
So, if anybody has any ideas how to achieve that, please share.
Thanks.
P.S. Don't hesitate to ask any additional information.

Answer 1

I created nested categories by creating a new model 'PostSubCategory' that allows the user to assign the parent category to the child category when they create the child category:
var keystone = require('keystone');
var Types = keystone.Field.Types;
/**
* PostSubCategory Model
* ==================
*/
var PostSubCategory = new keystone.List('PostSubCategory', {
autokey: { from: 'name', path: 'key', unique: true },
});
PostSubCategory.add({
name: {
type: String,
required: true
},
parentCategory: {
type: Types.Relationship,
ref: 'PostCategory',
required: true,
initial: true
}
});
PostSubCategory.relationship({ ref: 'Post', path: 'subcategories' });
PostSubCategory.register();
Then in my Post.js, I add a field to choose a subcategory with a filter on that field to only select from subcategories that are children of the parent category selected:
subcategory: {
type: Types.Relationship,
ref: 'PostSubCategory',
many: false,
filters: { parentCategory: ':categories' }
}
I'm not sure how well this would work for deeper nesting, and I do have an issue in the edit Post admin ui where changing the parent category for a post doesn't update the available subcategories to choose from until you save and refresh. But it got me far enough along for getting parent/child categories to work.