yjs/src/Types/Map.js
2015-11-30 15:02:34 +01:00

315 lines
9.5 KiB
JavaScript

/* @flow */
'use strict'
module.exports = function (Y /* :any */) {
class YMap {
/* ::
_model: Id;
os: Y.AbstractDatabase;
map: Object;
contents: any;
opContents: Object;
eventHandler: Function;
*/
constructor (os, model, contents, opContents) {
this._model = model.id
this.os = os
this.map = Y.utils.copyObject(model.map)
this.contents = contents
this.opContents = opContents
this.eventHandler = new Y.utils.EventHandler(ops => {
var userEvents = []
for (var i in ops) {
var op = ops[i]
var oldValue
// key is the name to use to access (op)content
var key = op.struct === 'Delete' ? op.key : op.parentSub
// compute oldValue
if (this.opContents[key] != null) {
let prevType = this.opContents[key]
oldValue = () => {// eslint-disable-line
return new Promise((resolve) => {
this.os.requestTransaction(function *() {// eslint-disable-line
var type = yield* this.getType(prevType)
resolve(type)
})
})
}
} else {
oldValue = this.contents[key]
}
// compute op event
if (op.struct === 'Insert') {
if (op.left === null) {
if (op.opContent != null) {
delete this.contents[key]
if (op.deleted) {
delete this.opContents[key]
} else {
this.opContents[key] = op.opContent
}
} else {
delete this.opContents[key]
if (op.deleted) {
delete this.contents[key]
} else {
this.contents[key] = op.content
}
}
this.map[key] = op.id
var insertEvent
if (oldValue === undefined) {
insertEvent = {
name: key,
object: this,
type: 'add'
}
} else {
insertEvent = {
name: key,
object: this,
oldValue: oldValue,
type: 'update'
}
}
userEvents.push(insertEvent)
}
} else if (op.struct === 'Delete') {
if (Y.utils.compareIds(this.map[key], op.target)) {
delete this.opContents[key]
delete this.contents[key]
var deleteEvent = {
name: key,
object: this,
oldValue: oldValue,
type: 'delete'
}
userEvents.push(deleteEvent)
}
} else {
throw new Error('Unexpected Operation!')
}
}
this.eventHandler.callEventListeners(userEvents)
})
}
get (key) {
// return property.
// if property does not exist, return null
// if property is a type, return a promise
if (key == null) {
throw new Error('You must specify key!')
}
if (this.opContents[key] == null) {
return this.contents[key]
} else {
return new Promise((resolve) => {
var oid = this.opContents[key]
this.os.requestTransaction(function *() {
var type = yield* this.getType(oid)
resolve(type)
})
})
}
}
/*
If there is a primitive (not a custom type), then return it.
Returns all primitive values, if propertyName is specified!
Note: modifying the return value could result in inconsistencies!
-- so make sure to copy it first!
*/
getPrimitive (key) {
if (key == null) {
return Y.utils.copyObject(this.contents)
} else {
return this.contents[key]
}
}
delete (key) {
var right = this.map[key]
if (right != null) {
var del = {
target: right,
struct: 'Delete'
}
var eventHandler = this.eventHandler
var modDel = Y.utils.copyObject(del)
modDel.key = key
eventHandler.awaitAndPrematurelyCall([modDel])
this.os.requestTransaction(function *() {
yield* this.applyCreatedOperations([del])
eventHandler.awaitedDeletes(1)
})
}
}
set (key, value) {
// set property.
// if property is a type, return a promise
// if not, apply immediately on this type an call event
var right = this.map[key] || null
var insert /* :any */ = {
left: null,
right: right,
origin: null,
parent: this._model,
parentSub: key,
struct: 'Insert'
}
return new Promise((resolve) => {
if (value instanceof Y.utils.CustomType) {
// construct a new type
this.os.requestTransaction(function *() {
var typeid = yield* value.createType.call(this)
var type = yield* this.getType(typeid)
insert.opContent = typeid
insert.id = this.store.getNextOpId()
yield* this.applyCreatedOperations([insert])
resolve(type)
})
} else {
insert.content = value
insert.id = this.os.getNextOpId()
var eventHandler = this.eventHandler
eventHandler.awaitAndPrematurelyCall([insert])
this.os.requestTransaction(function *() {
yield* this.applyCreatedOperations([insert])
eventHandler.awaitedInserts(1)
})
resolve(value)
}
})
}
observe (f) {
this.eventHandler.addEventListener(f)
}
unobserve (f) {
this.eventHandler.removeEventListener(f)
}
/*
Observe a path.
E.g.
```
o.set('textarea', Y.TextBind)
o.observePath(['textarea'], function(t){
// is called whenever textarea is replaced
t.bind(textarea)
})
returns a Promise that contains a function that removes the observer from the path.
*/
observePath (path, f) {
var self = this
function observeProperty (events) {
// call f whenever path changes
for (var i = 0; i < events.length; i++) {
var event = events[i]
if (event.name === propertyName) {
// call this also for delete events!
var property = self.get(propertyName)
if (property instanceof Promise) {
property.then(f)
} else {
f(property)
}
}
}
}
if (path.length < 1) {
throw new Error('Path must contain at least one element!')
} else if (path.length === 1) {
var propertyName = path[0]
var property = self.get(propertyName)
if (property instanceof Promise) {
property.then(f)
} else {
f(property)
}
this.observe(observeProperty)
return Promise.resolve(function () {
self.unobserve(f)
})
} else {
var deleteChildObservers
var resetObserverPath = function () {
var promise = self.get(path[0])
if (!promise instanceof Promise) {
// its either not defined or a primitive value
promise = self.set(path[0], Y.Map)
}
return promise.then(function (map) {
return map.observePath(path.slice(1), f)
}).then(function (_deleteChildObservers) {
// update deleteChildObservers
deleteChildObservers = _deleteChildObservers
return Promise.resolve() // Promise does not return anything
})
}
var observer = function (events) {
for (var e in events) {
var event = events[e]
if (event.name === path[0]) {
if (deleteChildObservers != null) {
deleteChildObservers()
}
if (event.type === 'add' || event.type === 'update') {
resetObserverPath()
}
// TODO: what about the delete events?
}
}
}
self.observe(observer)
return resetObserverPath().then(
// this promise contains a function that deletes all the child observers
// and how to unobserve the observe from this object
new Promise.resolve(function () { // eslint-disable-line
if (deleteChildObservers != null) {
deleteChildObservers()
}
self.unobserve(observer)
})
)
}
}
* _changed (transaction, op) {
if (op.struct === 'Delete') {
var target = yield* transaction.getOperation(op.target)
op.key = target.parentSub
}
this.eventHandler.receivedOp(op)
}
}
Y.Map = new Y.utils.CustomType({
class: YMap,
createType: function * YMapCreator () {
var modelid = this.store.getNextOpId()
var model = {
map: {},
struct: 'Map',
type: 'Map',
id: modelid
}
yield* this.applyCreatedOperations([model])
return modelid
},
initType: function * YMapInitializer (os, model) {
var contents = {}
var opContents = {}
var map = model.map
for (var name in map) {
var op = yield* this.getOperation(map[name])
if (op.opContent != null) {
opContents[name] = op.opContent
} else {
contents[name] = op.content
}
}
return new YMap(os, model, contents, opContents)
}
})
}