categories.js

orion.addEntity('categories', {
    category: {
        type: String,
        label: 'Category',
        optional: false
    },
    attributes: {
        type: [String],
        label: 'Attributes',
        optional: true
    }
}, {
    icon: 'bookmark',
    sidebarName: 'Categories',
    pluralName: 'Categories',
    singularName: 'Category',
    tableColumns: [
        {
            data: 'category',
            title: 'Category'
        },
        {
            data: 'attributes',
            title: 'Attributes'
        }
    ]
});

reviews.js

orion.admin.addAdminSubscription(orion.subs.subscribe('entity', 'categories'));

var baseSchema = orion.getNewEntitySchema({
    product: {
        type: String,
        label: 'Product',
        optional: false
    },
    category: {
        type: String,
        autoform: {
            options: function() {
                return orion.entities.categories.collection.find().fetch().map(function(value) {
                    return {
                        value: value._id,
                        label: value.category
                    };
                });
            }
        },
        optional: false,
        label: 'Category'
    }
});

function updateReviewsSchema(attributes) {
    var reviewsSchema = attributes.reduce(function(schema, attribute) {
        schema['reviews.' + attribute] = {
            type: Number,
            label: attribute,
            min: 1,
            max: 10,
            optional: true,
            defaultValue: 1
        }
        return schema;
    }, {
        reviews: {
            type: Object,
            label: 'Reviews',
            optional: true
        }
    });
    var schema = _.extend(_.clone(baseSchema), reviewsSchema);
    orion.entities.reviews.schema = schema;
    orion.entities.reviews.collection.attachSchema(new SimpleSchema(schema), {
        replace: true
    });
}

if (Meteor.isServer) {
    Meteor.methods({
        updateReviewsSchema: function(attributes) {
            updateReviewsSchema(attributes);
        }
    })
}

if (Meteor.isClient) {
    Tracker.autorun(function() {
        var categoryId = Session.get('categoryId');
        if (!categoryId) {
            return;
        }
        var category = orion.entities.categories.collection.findOne(categoryId);
        Meteor.call('updateReviewsSchema', category.attributes);
        updateReviewsSchema(category.attributes);
        AutoForm.invalidateFormContext('createEntityForm');
        AutoForm.invalidateFormContext('updateEntityForm');
    })
    Template.adminEntitiesCreate.events({
        'change select[data-schema-key="category"]': function(e) {
            Session.set('categoryId',$(e.currentTarget).val());
        }
    });
    Template.adminEntitiesCreate.rendered = function() {
        Session.set('categoryId',$('select[data-schema-key="category"]').val());
    };
    Template.adminEntitiesUpdate.events({
        'change select[data-schema-key="category"]': function(e) {
            Session.set('categoryId',$(e.currentTarget).val());
        }
    });
    Template.adminEntitiesUpdate.rendered = function() {
        Session.set('categoryId',$('select[data-schema-key="category"]').val());
    };
}

orion.addEntity('reviews', _.clone(baseSchema), {
    icon: 'bookmark',
    sidebarName: 'Reviews',
    pluralName: 'Reviews',
    singularName: 'Review',
    tableColumns: [
        {
            data: 'product',
            title: 'Product'
        }
    ]
});