grapher/lib/links/extension.js

import { Mongo } from 'meteor/mongo';
import { LINK_STORAGE } from './constants.js';
import Linker from './linker.js';

Object.assign(Mongo.Collection.prototype, {
    /**
     * The data we add should be valid for config.schema.js
     */
    addLinks(data) {
        if (!this[LINK_STORAGE]) {
            this[LINK_STORAGE] = {};
        }

        _.each(data, (linkConfig, linkName) => {
            if (this[LINK_STORAGE][linkName]) {
                throw new Meteor.Error(
                    `You cannot add the link with name: ${linkName} because it was already added to ${
                        this._name
                    } collection`
                );
            }

            const linker = new Linker(this, linkName, linkConfig);

            _.extend(this[LINK_STORAGE], {
                [linkName]: linker,
            });
        });
    },

    getLinks() {
        return this[LINK_STORAGE];
    },

    getLinker(name) {
        if (this[LINK_STORAGE]) {
            return this[LINK_STORAGE][name];
        }
    },

    hasLink(name) {
        if (!this[LINK_STORAGE]) {
            return false;
        }

        return !!this[LINK_STORAGE][name];
    },

    getLink(objectOrId, name) {
        let linkData = this[LINK_STORAGE];

        if (!linkData) {
            throw new Meteor.Error(
                `There are no links defined for collection: ${this._name}`
            );
        }

        if (!linkData[name]) {
            throw new Meteor.Error(
                `There is no link ${name} for collection: ${this._name}`
            );
        }

        const linker = linkData[name];
        let object = objectOrId;
        if (typeof objectOrId == 'string') {
            if (!linker.isVirtual()) {
                object = this.findOne(objectOrId, {
                    fields: {
                        [linker.linkStorageField]: 1,
                    },
                });
            } else {
                object = { _id: objectOrId };
            }

            if (!object) {
                throw new Meteor.Error(
                    `We could not find any object with _id: "${objectOrId}" within the collection: ${
                        this._name
                    }`
                );
            }
        }

        return linkData[name].createLink(object);
    },
});