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Ghost/core/server/models/plugins/collision.js
Hannah Wolfe 512808e8b4 🐛 Added 409 UpdateCollisionError for the editor ()
fixes 

- This is a user error, not a system error
- Downgrading to a 4xx status code means it doesn't appear in logs where it shouldn't
- We didn't have a suitable error available so I added UpdateCollisionError with 409 status
2017-08-15 12:06:40 +02:00

87 lines
3.6 KiB
JavaScript

var moment = require('moment-timezone'),
Promise = require('bluebird'),
_ = require('lodash'),
errors = require('../../errors');
module.exports = function (Bookshelf) {
var ParentModel = Bookshelf.Model,
Model;
Model = Bookshelf.Model.extend({
/**
* Update collision protection.
*
* IMPORTANT NOTES:
* The `sync` method is called for any query e.g. update, add, delete, fetch
*
* We had the option to override Bookshelf's `save` method, but hooking into the `sync` method gives us
* the ability to access the `changed` object. Bookshelf already knows which attributes has changed.
*
* Bookshelf's timestamp function can't be overridden, as it's synchronous, there is no way to return an Error.
*
* If we want to enable the collision plugin for other tables, the queries might need to run in a transaction.
* This depends on if we fetch the model before editing. Imagine two concurrent requests come in, both would fetch
* the same current database values and both would succeed to update and override each other.
*/
sync: function timestamp(options) {
var parentSync = ParentModel.prototype.sync.apply(this, arguments),
originalUpdateSync = parentSync.update,
self = this;
// CASE: only enabled for posts table
if (this.tableName !== 'posts' ||
!self.serverData ||
((options.method !== 'update' && options.method !== 'patch') || !options.method)
) {
return parentSync;
}
/**
* Only hook into the update sync
*
* IMPORTANT NOTES:
* Even if the client sends a different `id` property, it get's ignored by bookshelf.
* Because you can't change the `id` of an existing post.
*
* HTML is always auto generated, ignore.
*/
parentSync.update = function update() {
var changed = _.omit(self.changed, [
'created_at', 'updated_at', 'author_id', 'id',
'published_by', 'updated_by', 'html', 'plaintext'
]),
clientUpdatedAt = moment(self.clientData.updated_at || self.serverData.updated_at || new Date()),
serverUpdatedAt = moment(self.serverData.updated_at || clientUpdatedAt);
if (Object.keys(changed).length) {
if (clientUpdatedAt.diff(serverUpdatedAt) !== 0) {
return Promise.reject(new errors.UpdateCollisionError({
message: 'Saving failed! Someone else is editing this post.',
code: 'UPDATE_COLLISION'
}));
}
}
return originalUpdateSync.apply(this, arguments);
};
return parentSync;
},
/**
* We have to remember current server data and client data.
* The `sync` method has no access to it.
* `updated_at` is already set to "Date.now" when the overridden `sync.update` is called.
* See https://github.com/tgriesser/bookshelf/blob/79c526870e618748caf94e7476a0bc796ee090a6/src/model.js#L955
*/
save: function save(data) {
this.clientData = _.cloneDeep(data) || {};
this.serverData = _.cloneDeep(this.attributes);
return ParentModel.prototype.save.apply(this, arguments);
}
});
Bookshelf.Model = Model;
};