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ghost/core/server/api/posts.js
Katharina Irrgang c93f03b87e post update collision detection (#8328) (#8362)
closes #5599

If two users edit the same post, it can happen that they override each others content or post settings. With this change this won't happen anymore.

 Update collision for posts
- add a new bookshelf plugin to detect these changes
- use the `changed` object of bookshelf -> we don't have to create our own diff
- compare client and server updated_at field
- run editing posts in a transaction (see comments in code base)

🙀  update collision for tags
- `updateTags` for adding posts on `onCreated` - happens after the post was inserted
   --> it's "okay" to attach the tags afterwards on insert
   --> there is no need to add collision for inserting data
   --> it's very hard to move the updateTags call to `onCreating`, because the `updateTags` function queries the database to look up the affected post
- `updateTags` while editing posts on `onSaving` - all operations run in a transactions and are rolled back if something get's rejected

- Post model edit: if we push a transaction from outside, take this one

  introduce options.forUpdate
- if two queries happening in a transaction we have to signalise knex/mysql that we select for an update
- otherwise the following case happens:
  >> you fetch posts for an update
  >> a user requests comes in and updates the post (e.g. sets title to "X")
  >> you update the fetched posts, title would get overriden to the old one

use options.forUpdate and protect internal post updates: model listeners
- use a transaction for listener updates
- signalise forUpdate
- write a complex test

use options.forUpdate and protect internal post updates: scheduling
- publish endpoint runs in a transaction
- add complex test
- @TODO: right now scheduling api uses posts api, therefor we had to extend the options for api's
  >> allowed to pass transactions through it
  >> but these are only allowed if defined from outside {opts: [...]}
  >> so i think this is fine and not dirty
  >> will wait for opinions
  >> alternatively we have to re-write the scheduling endpoint to use the models directly
2017-04-19 14:53:23 +01:00

243 lines
7.9 KiB
JavaScript

// # Posts API
// RESTful API for the Post resource
var Promise = require('bluebird'),
_ = require('lodash'),
dataProvider = require('../models'),
errors = require('../errors'),
utils = require('./utils'),
pipeline = require('../utils/pipeline'),
i18n = require('../i18n'),
docName = 'posts',
allowedIncludes = [
'created_by', 'updated_by', 'published_by', 'author', 'tags', 'fields',
'next', 'previous', 'next.author', 'next.tags', 'previous.author', 'previous.tags'
],
posts;
/**
* ### Posts API Methods
*
* **See:** [API Methods](index.js.html#api%20methods)
*/
posts = {
/**
* ## Browse
* Find a paginated set of posts
*
* Will only return published posts unless we have an authenticated user and an alternative status
* parameter.
*
* Will return without static pages unless told otherwise
*
*
* @public
* @param {{context, page, limit, status, staticPages, tag, featured}} options (optional)
* @returns {Promise<Posts>} Posts Collection with Meta
*/
browse: function browse(options) {
var extraOptions = ['status'],
permittedOptions,
tasks;
// Workaround to remove static pages from results
// TODO: rework after https://github.com/TryGhost/Ghost/issues/5151
if (options && options.context && (options.context.user || options.context.internal)) {
extraOptions.push('staticPages');
}
permittedOptions = utils.browseDefaultOptions.concat(extraOptions);
/**
* ### Model Query
* Make the call to the Model layer
* @param {Object} options
* @returns {Object} options
*/
function modelQuery(options) {
return dataProvider.Post.findPage(options);
}
// Push all of our tasks into a `tasks` array in the correct order
tasks = [
utils.validate(docName, {opts: permittedOptions}),
utils.handlePublicPermissions(docName, 'browse'),
utils.convertOptions(allowedIncludes),
modelQuery
];
// Pipeline calls each task passing the result of one to be the arguments for the next
return pipeline(tasks, options);
},
/**
* ## Read
* Find a post, by ID, UUID, or Slug
*
* @public
* @param {Object} options
* @return {Promise<Post>} Post
*/
read: function read(options) {
var attrs = ['id', 'slug', 'status', 'uuid'],
tasks;
/**
* ### Model Query
* Make the call to the Model layer
* @param {Object} options
* @returns {Object} options
*/
function modelQuery(options) {
return dataProvider.Post.findOne(options.data, _.omit(options, ['data']));
}
// Push all of our tasks into a `tasks` array in the correct order
tasks = [
utils.validate(docName, {attrs: attrs, opts: options.opts || []}),
utils.handlePublicPermissions(docName, 'read'),
utils.convertOptions(allowedIncludes),
modelQuery
];
// Pipeline calls each task passing the result of one to be the arguments for the next
return pipeline(tasks, options).then(function formatResponse(result) {
// @TODO make this a formatResponse task?
if (result) {
return {posts: [result.toJSON(options)]};
}
return Promise.reject(new errors.NotFoundError({message: i18n.t('errors.api.posts.postNotFound')}));
});
},
/**
* ## Edit
* Update properties of a post
*
* @public
* @param {Post} object Post or specific properties to update
* @param {{id (required), context, include,...}} options
* @return {Promise(Post)} Edited Post
*/
edit: function edit(object, options) {
var tasks;
/**
* ### Model Query
* Make the call to the Model layer
* @param {Object} options
* @returns {Object} options
*/
function modelQuery(options) {
return dataProvider.Post.edit(options.data.posts[0], _.omit(options, ['data']));
}
// Push all of our tasks into a `tasks` array in the correct order
tasks = [
utils.validate(docName, {opts: utils.idDefaultOptions.concat(options.opts || [])}),
utils.handlePermissions(docName, 'edit'),
utils.convertOptions(allowedIncludes),
modelQuery
];
// Pipeline calls each task passing the result of one to be the arguments for the next
return pipeline(tasks, object, options).then(function formatResponse(result) {
if (result) {
var post = result.toJSON(options);
// If previously was not published and now is (or vice versa), signal the change
post.statusChanged = false;
if (result.updated('status') !== result.get('status')) {
post.statusChanged = true;
}
return {posts: [post]};
}
return Promise.reject(new errors.NotFoundError({message: i18n.t('errors.api.posts.postNotFound')}));
});
},
/**
* ## Add
* Create a new post along with any tags
*
* @public
* @param {Post} object
* @param {{context, include,...}} options
* @return {Promise(Post)} Created Post
*/
add: function add(object, options) {
var tasks;
/**
* ### Model Query
* Make the call to the Model layer
* @param {Object} options
* @returns {Object} options
*/
function modelQuery(options) {
return dataProvider.Post.add(options.data.posts[0], _.omit(options, ['data']));
}
// Push all of our tasks into a `tasks` array in the correct order
tasks = [
utils.validate(docName),
utils.handlePermissions(docName, 'add'),
utils.convertOptions(allowedIncludes),
modelQuery
];
// Pipeline calls each task passing the result of one to be the arguments for the next
return pipeline(tasks, object, options).then(function formatResponse(result) {
var post = result.toJSON(options);
if (post.status === 'published') {
// When creating a new post that is published right now, signal the change
post.statusChanged = true;
}
return {posts: [post]};
});
},
/**
* ## Destroy
* Delete a post, cleans up tag relations, but not unused tags
*
* @public
* @param {{id (required), context,...}} options
* @return {Promise}
*/
destroy: function destroy(options) {
var tasks;
/**
* @function deletePost
* @param {Object} options
*/
function deletePost(options) {
var Post = dataProvider.Post,
data = _.defaults({status: 'all'}, options),
fetchOpts = _.defaults({require: true, columns: 'id'}, options);
return Post.findOne(data, fetchOpts).then(function () {
return Post.destroy(options).return(null);
}).catch(Post.NotFoundError, function () {
throw new errors.NotFoundError({message: i18n.t('errors.api.posts.postNotFound')});
});
}
// Push all of our tasks into a `tasks` array in the correct order
tasks = [
utils.validate(docName, {opts: utils.idDefaultOptions}),
utils.handlePermissions(docName, 'destroy'),
utils.convertOptions(allowedIncludes),
deletePost
];
// Pipeline calls each task passing the result of one to be the arguments for the next
return pipeline(tasks, options);
}
};
module.exports = posts;