2021-04-29 12:03:54 +02:00

56 lines
1.3 KiB
JavaScript

'use strict';
/**
* Loaders.js service
*
* @description: A set of functions similar to controller's actions to avoid code duplication.
*/
const _ = require('lodash');
const DataLoader = require('dataloader');
module.exports = {
loaders: {},
initializeLoader() {
this.resetLoaders();
// Create loaders for each relational field (exclude core models & plugins).
Object.values(strapi.contentTypes).forEach(model => this.createLoader(model.uid));
},
resetLoaders() {
this.loaders = {};
},
createLoader(modelUID) {
if (this.loaders[modelUID]) {
return this.loaders[modelUID];
}
const loadFn = queries => this.batchQuery(modelUID, queries);
const loadOptions = {
cacheKeyFn: key => this.serializeKey(key),
};
this.loaders[modelUID] = new DataLoader(loadFn, loadOptions);
},
serializeKey(key) {
return _.isObjectLike(key) ? JSON.stringify(key) : key;
},
async batchQuery(modelUID, queries) {
// Extract queries from keys and merge similar queries.
return Promise.all(queries.map(query => this.makeQuery(modelUID, query)));
},
async makeQuery(modelUID, query = {}) {
if (query.single === true) {
return strapi.query(modelUID).findOne(query.filters, []);
}
return strapi.query(modelUID).find(query.filters, []);
},
};