ObjectStateMutations.js

/**
 * Copyright (c) 2015-present, Parse, LLC.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @flow
 */

import encode from './encode';
import ParseFile from './ParseFile';
import ParseObject from './ParseObject';
import ParseRelation from './ParseRelation';
import TaskQueue from './TaskQueue';
import { RelationOp } from './ParseOp';

import type { Op } from './ParseOp';

export type AttributeMap = { [attr: string]: any };
export type OpsMap = { [attr: string]: Op };
export type ObjectCache = { [attr: string]: string };

export type State = {
  serverData: AttributeMap;
  pendingOps: Array<OpsMap>;
  objectCache: ObjectCache;
  tasks: TaskQueue;
  existed: boolean
};

export function defaultState(): State {
  return {
    serverData: {},
    pendingOps: [{}],
    objectCache: {},
    tasks: new TaskQueue(),
    existed: false
  };
}

export function setServerData(serverData: AttributeMap, attributes: AttributeMap) {
  for (const attr in attributes) {
    if (typeof attributes[attr] !== 'undefined') {
      serverData[attr] = attributes[attr];
    } else {
      delete serverData[attr];
    }
  }
}

export function setPendingOp(pendingOps: Array<OpsMap>, attr: string, op: ?Op) {
  const last = pendingOps.length - 1;
  if (op) {
    pendingOps[last][attr] = op;
  } else {
    delete pendingOps[last][attr];
  }
}

export function pushPendingState(pendingOps: Array<OpsMap>) {
  pendingOps.push({});
}

export function popPendingState(pendingOps: Array<OpsMap>): OpsMap {
  const first = pendingOps.shift();
  if (!pendingOps.length) {
    pendingOps[0] = {};
  }
  return first;
}

export function mergeFirstPendingState(pendingOps: Array<OpsMap>) {
  const first = popPendingState(pendingOps);
  const next = pendingOps[0];
  for (const attr in first) {
    if (next[attr] && first[attr]) {
      const merged = next[attr].mergeWith(first[attr]);
      if (merged) {
        next[attr] = merged;
      }
    } else {
      next[attr] = first[attr];
    }
  }
}

export function estimateAttribute(serverData: AttributeMap, pendingOps: Array<OpsMap>, className: string, id: ?string, attr: string): mixed {
  let value = serverData[attr];
  for (let i = 0; i < pendingOps.length; i++) {
    if (pendingOps[i][attr]) {
      if (pendingOps[i][attr] instanceof RelationOp) {
        if (id) {
          value = pendingOps[i][attr].applyTo(
            value,
            { className: className, id: id },
            attr
          );
        }
      } else {
        value = pendingOps[i][attr].applyTo(value);
      }
    }
  }
  return value;
}

export function estimateAttributes(serverData: AttributeMap, pendingOps: Array<OpsMap>, className: string, id: ?string): AttributeMap {
  const data = {};
  let attr;
  for (attr in serverData) {
    data[attr] = serverData[attr];
  }
  for (let i = 0; i < pendingOps.length; i++) {
    for (attr in pendingOps[i]) {
      if (pendingOps[i][attr] instanceof RelationOp) {
        if (id) {
          data[attr] = pendingOps[i][attr].applyTo(
            data[attr],
            { className: className, id: id },
            attr
          );
        }
      } else {
        if (attr.includes('.')) {
          // convert a.b.c into { a: { b: { c: value } } }
          const fields = attr.split('.');
          const last = fields[fields.length - 1];
          let object = Object.assign({}, data);
          for (let i = 0; i < fields.length - 1; i++) {
            object = object[fields[i]];
          }
          object[last] = pendingOps[i][attr].applyTo(object[last]);
        } else {
          data[attr] = pendingOps[i][attr].applyTo(data[attr]);
        }
      }
    }
  }
  return data;
}

export function commitServerChanges(serverData: AttributeMap, objectCache: ObjectCache, changes: AttributeMap) {
  for (const attr in changes) {
    const val = changes[attr];
    serverData[attr] = val;
    if (val &&
      typeof val === 'object' &&
      !(val instanceof ParseObject) &&
      !(val instanceof ParseFile) &&
      !(val instanceof ParseRelation)
    ) {
      const json = encode(val, false, true);
      objectCache[attr] = JSON.stringify(json);
    }
  }
}