Sometimes there is a need to track changes in a sap.ui.model.json.JSONModel from a certain point in time and be able to roll back these changes.
Function
sap.ui.define([
"sap/ui/model/json/JSONModel",
"sap/base/util/deepClone",
"sap/base/util/deepEqual"
], function(JSONModel, deepClone, deepEqual) {
"use strict";
return JSONModel.extend("<PROJECT_PATH>.model.<NAME>", {
/**
* @class <NAME>
* @summary <SUMMARY>
* @extends sap.ui.model.json.JSONModel
*/
constructor: function() {
JSONModel.prototype.constructor.call(this, {
propertyA: undefined,
propertyB: undefined,
propertyC: undefined
});
},
/**
* @memberOf <NAME>
* @description placeholder function - replace with the relevant business logic
* @public
*/
readData: function() {
this.setData({
propertyA: new Date('1995-12-17T03:24:00'),
propertyB: "INITIAL",
propertyC: 44
});
this._createUndoObject();
},
/**
* @memberOf <NAME>
* @description creating a deep clone of the model data to be able to determine changes afterwards
*/
_createUndoObject: function() {
this.oUndoObject = deepClone(this.getData()); //maybe adjust maxDepth parameter
},
/**
* @memberOf <NAME>
* @description undo changes
*/
undo: function() {
this.setData(this.oUndoObject);
},
/**
* @memberOf <NAME>
* @description Check if there are changes
*/
hasChanges: function() {
var bHasChanges = !deepEqual(this.oUndoObject, this.getData());
return bHasChanges;
}
});
});
Example
var oModel = new UndoModel();
oModel.readData();
oModel.hasChanges();
//Expected output: false
oModel.setProperty("/propertyB", "CHANGE");
oModel.hasChanges();
//Expected output: true
oModel.getProperty("/propertyB");
//Expected output: 'CHANGE'
oModel.undo();
oModel.hasChanges();
//Expected output: false
oModel.getProperty("/propertyB");
//Expected output: 'INITIAL'