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import DataObject from './DataObject.js'
/*
DataModel holds a map of string,value pairs, sometimes fetched from or sent to a back-end server.
It fires events when values are changed.
options:
fieldDataObjects ({}): a map of fieldName (string) to DataObject (class), used to create sub-object in this Model's data
*/
export default class extends DataObject {
constructor(data={}, options={}){
super(options)
if(typeof this.options.fieldDataObjects === 'undefined'){
this.options.fieldDataObjects = {}
}
this.data = {}
this.setBatch(data)
}
cleanup() {
super.cleanup()
this.data = null
}
/*
Find a value held within this DataModel.
Return values may be native types or, if mapped by options.fieldDataObjects, another DataObject
*/
has(fieldName){
return typeof this.data[fieldName] !== 'undefined'
}
get(fieldName, defaultValue=null){
if(typeof this.data[fieldName] === 'undefined' || this.data[fieldName] === null || this.data[fieldName] === ''){
return defaultValue
}
return this.data[fieldName]
}
// Set a key/value pair.
set(fieldName, value){
var batch = {}
batch[fieldName] = value
return this.setBatch(batch)
}
/*
Set a group of values. The 'values' parameter should be an object that works in for(key in values) loops like a dictionary: {}
If a key is in options.fieldDataObjects then the value will be used to contruct a DataObject and that will be the saved value.
*/
setBatch(values){
let changes = {}
let changed = false
for(let key in values){
let result = this._set(key, values[key])
if(result !== DataObject._NO_CHANGE){
changed = true
changes[key] = result
this.trigger(`changed:${key}`, this, key, result)
}
}
if(changed){
this.trigger('changed', this, changes)
}
return changes
}
increment(fieldName, amount=1){
const currentVal = fieldName in this.data ? this.data[fieldName] : 0
this.set(fieldName, currentVal + amount)
}
_set(fieldName, data){
// _set does not fire any events, so you probably want to use set or setBatch
if(data instanceof DataObject){
if(this.data[fieldName] instanceof DataObject){
this.data[fieldName].reset(data.data)
} else {
this.data[fieldName] = data
}
} else if(this.options.fieldDataObjects[fieldName]){
if(this.data[fieldName]){
this.data[fieldName].reset(data)
} else {
this.data[fieldName] = new this.options.fieldDataObjects[fieldName](data)
}
} else {
if(this.data[fieldName] === data){
return DataObject._NO_CHANGE
}
if(this.data[fieldName] instanceof DataObject){
this.data[fieldName].reset(data)
} else {
this.data[fieldName] = data
}
}
return this.data[fieldName]
}
reset(data={}){
for(var key in this.data){
if(typeof data[key] === 'undefined'){
this.data[key] = null
}
}
this.setBatch(data)
this.trigger('reset', this)
}
equals(obj){
if(obj === null || typeof obj === 'undefined') return false
if(this === obj) return true
if(typeof obj !== typeof this) return false
if(obj.get('id') === this.get('id')) return true
return false
}
}