I have upgrade Extjs 4.2 to 5.1.1 now combobox getting error cannot read property apply..but which is working perfect in extjs 4.2

Question

Uncaught TypeError: Cannot read property 'apply' of undefined ext-all-rtl-debug.js?_dc=1434006887415:122446Ext.define.getDisplayValue ext-all-rtl-debug.js?_dc=1434006887415:122446Ext.define.updateValue ext-all-rtl-debug.js?_dc=1434006887415:122405Ext.define.onValueCollectionEndUpdate ext-all-rtl-debug.js?_dc=1434006887415:122187fire ext-all-rtl-debug.js?_dc=1434006887415:11803doFireEvent ext-all-rtl-debug.js?_dc=1434006887415:12332fireEventArgs ext-all-rtl-debug.js?_dc=1434006887415:12300Ext.define.notify ext-all-rtl-debug.js?_dc=1434006887415:44074Ext.define.endUpdate ext-all-rtl-debug.js?_dc=1434006887415:42996Ext.define.doSetValue ext-all-rtl-debug.js?_dc=1434006887415:122369Ext.define.setValue ext-all-rtl-debug.js?_dc=1434006887415:122270Ext.define.setValueOnData ext-all-rtl-debug.js?_dc=1434006887415:121833Ext.define.bindStore ext-all-rtl-debug.js?_dc=1434006887415:121774Ext.define.setStore ext-all-rtl-debug.js?_dc=1434006887415:78436(anonymous function) ext-all-rtl-debug.js?_dc=1434006887415:6243Ext.define.bindStore ext-all-rtl-debug.js?_dc=1434006887415:121769Ext.define.setStore ext-all-rtl-debug.js?_dc=1434006887415:78436Ext.Configurator.configure ext-all-rtl-debug.js?_dc=1434006887415:6645Ext.Base.Base.addMembers.initConfig ext-all-rtl-debug.js?_dc=1434006887415:7424Ext.define.constructor ext-all-rtl-debug.js?_dc=1434006887415:39045constructor ext-all-rtl-debug.js?_dc=1434006887415:7660Ext.ClassManager.Ext.apply.widget ext-all-rtl-debug.js?_dc=1434006887415:8934Ext.define.create ext-all-rtl-debug.js?_dc=1434006887415:14599Ext.define.lookupComponent ext-all-rtl-debug.js?_dc=1434006887415:76363Ext.define.privates.prepareItems ext-all-rtl-debug.js?_dc=1434006887415:76752Ext.define.add ext-all-rtl-debug.js?_dc=1434006887415:75977Ext.define.initItems ext-all-rtl-debug.js?_dc=1434006887415:76301Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initItems ext-all-rtl-debug.js?_dc=1434006887415:88789Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initItems ext-all-rtl-debug.js?_dc=1434006887415:119267Ext.define.initComponent ext-all-rtl-debug.js?_dc=1434006887415:76269Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initComponent ext-all-rtl-debug.js?_dc=1434006887415:88783Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initComponent ext-all-rtl-debug.js?_dc=1434006887415:119247Ext.define.constructor ext-all-rtl-debug.js?_dc=1434006887415:39089constructor ext-all-rtl-debug.js?_dc=1434006887415:7660Ext.ClassManager.Ext.apply.widget ext-all-rtl-debug.js?_dc=1434006887415:8934Ext.define.create ext-all-rtl-debug.js?_dc=1434006887415:14599Ext.define.lookupComponent ext-all-rtl-debug.js?_dc=1434006887415:76363Ext.define.privates.prepareItems ext-all-rtl-debug.js?_dc=1434006887415:76752Ext.define.add ext-all-rtl-debug.js?_dc=1434006887415:75977Ext.define.initItems ext-all-rtl-debug.js?_dc=1434006887415:76301Ext.define.initComponent ext-all-rtl-debug.js?_dc=1434006887415:76269Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initComponent ext-all-rtl-debug.js?_dc=1434006887415:118849Ext.define.constructor ext-all-rtl-debug.js?_dc=1434006887415:39089constructor ext-all-rtl-debug.js?_dc=1434006887415:7660Ext.ClassManager.Ext.apply.widget ext-all-rtl-debug.js?_dc=1434006887415:8934Ext.define.create ext-all-rtl-debug.js?_dc=1434006887415:14599Ext.define.lookupComponent ext-all-rtl-debug.js?_dc=1434006887415:76363Ext.define.privates.prepareItems ext-all-rtl-debug.js?_dc=1434006887415:76752Ext.define.add ext-all-rtl-debug.js?_dc=1434006887415:75977Ext.define.initItems ext-all-rtl-debug.js?_dc=1434006887415:76301Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initItems ext-all-rtl-debug.js?_dc=1434006887415:88789Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initItems ext-all-rtl-debug.js?_dc=1434006887415:119267Ext.define.initComponent ext-all-rtl-debug.js?_dc=1434006887415:76269Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initComponent ext-all-rtl-debug.js?_dc=1434006887415:88783Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.initComponent ext-all-rtl-debug.js?_dc=1434006887415:119247Ext.define.constructor ext-all-rtl-debug.js?_dc=1434006887415:39089constructor ext-all-rtl-debug.js?_dc=1434006887415:7660(anonymous function) VM2495:3Ext.ClassManager.Ext.apply.create ext-all-rtl-debug.js?_dc=1434006887415:8897Ext.ClassManager.Ext.apply.instantiateByAlias ext-all-rtl-debug.js?_dc=1434006887415:8721Ext.Function.ExtFunction.alias ext-all-rtl-debug.js?_dc=1434006887415:4450Ext.define.OnSubMenuItemClick MenuDataView.js?_dc=1434006888341:51fire ext-all-rtl-debug.js?_dc=1434006887415:11803Ext.define.dispatch ext-all-rtl-debug.js?_dc=1434006887415:33357Ext.Base.Base.addMembers.callParent ext-all-rtl-debug.js?_dc=1434006887415:7381Ext.define.dispatch ext-all-rtl-debug.js?_dc=1434006887415:33539prototype.doFireEvent ext-all-rtl-debug.js?_dc=1434006887415:33465fireEventArgs ext-all-rtl-debug.js?_dc=1434006887415:12300fireEvent ext-all-rtl-debug.js?_dc=1434006887415:12274Ext.define.processUIEvent ext-all-rtl-debug.js?_dc=1434006887415:95171Ext.define.handleEvent ext-all-rtl-debug.js?_dc=1434006887415:95123fire ext-all-rtl-debug.js?_dc=1434006887415:11803Ext.define.fire ext-all-rtl-debug.js?_dc=1434006887415:18548Ext.define.publish ext-all-rtl-debug.js?_dc=1434006887415:18524Ext.define.doDelegatedEvent ext-all-rtl-debug.js?_dc=1434006887415:18574Ext.define.onDelegatedEvent ext-all-rtl-debug.js?_dc=1434006887415:18561Ext.Function.ExtFunction.bind.method

Answer 1

Ext.override(Ext.form.ComboBox,
                {
                    getDisplayValue: function () { 
                        //return this.lastSelectionText;
                        return this.selection!=null?this.selection.get('DisplayValue'):this.lastSelection;
                    }
                });

I got the answer..