@nozbe/watermelondb/decorators/relation/index.js

Build powerful React Native and React web apps that scale from hundreds to tens of thousands of records and remain fast

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
exports.__esModule = true;
exports.default = void 0;
var _common = require("../common");
var _Relation = _interopRequireDefault(require("../../Relation"));
// Defines a model property that fetches a record with a specific ID
// Returns an mutable Relation object
// - when the fetched record changes
// - when the record ID changes (new record must be fetched)
// - … or emits null whenever record ID is null
//
// If the record ID *can't* change, use `immutableRelation` for efficiency
//
// Property's setter assigns a new record (you pass the record, and the ID is set)
//
// relationIdColumn - name of the column with record ID
// relationTable - name of the table containing desired recods
//
// Example: a Task has a project it belongs to (and the project can change), so it may define:
//   @relation('project', 'project_id') project: Relation<Project>
var relation = function (relationTable, relationIdColumn, options) {
  return function (target, key, descriptor) {
    (0, _common.ensureDecoratorUsedProperly)(relationIdColumn, target, key, descriptor);
    return {
      get: function () {
        // $FlowFixMe
        var model = this;
        model._relationCache = model._relationCache || {};
        var cachedRelation = model._relationCache[key];
        if (cachedRelation) {
          return cachedRelation;
        }
        var newRelation = new _Relation.default(model.asModel, relationTable, relationIdColumn, options || {
          isImmutable: false
        });
        model._relationCache[key] = newRelation;
        return newRelation;
      },
      set: function () {
        throw new Error("Don't set relation directly. Use relation.set() instead");
      }
    };
  };
};
var _default = exports.default = relation;