Develop Reference

Problem with variable scope in nested Backbone views

I have a parent view which contains a Backgrid view. In the parent view's initialize section I define a variable isWellSelected. The variable is toggled in the Backgrid column logic when a tickbox is checked. I am able to watch the variable toggled when a box is ticked and unticked.
However, once an event fires the variable is no longer in scope for the event to see. I suspect I may need to pass the variable to the Backrgrid view but I am unsure how to do that correctly. Please advise.
app.wellCollectionView = Backbone.View.extend({
template: _.template($('#wellTemplate').html()),
initialize: function() {
this.isWellSelected = false;
// isWellSelected toggled to true when a tickbox is checked in the columns block.
var columns = [...];
// instantiate collection
var wellCollection = new app.wellCollection;
// Set up a grid view to use the pageable collection
var wellGrid = new Backgrid.Grid({
columns: columns,
collection: wellCollection
});
// Initialize the paginator
var paginator = new Backgrid.Extension.Paginator({
collection: wellCollection
});
// Render the template
this.$el.html(this.template());
// Render the grid
this.$el.append(wellGrid.render().el);
this.$el.append(paginator.render().$el);
wellCollection.fetch({reset: true}).then(function () {...});
},
events: {
'click #EvaluateWell': function(){
this.evalWell(event, this.isWellSelected);
console.log("In events - isWellSelected: " + this.isWellSelected);}
},
// More stuff
}
Constructive feedback welcome.
Thanks!
Adding a snippet for "columns" as per JT's request:
var columns = [
{
name: '',
label: 'Select',
cell: Backgrid.BooleanCell.extend({
events : {
'change': function(ev){
var $checkbox = $(ev.target);
var $checkboxes = $('.backgrid input[type=checkbox]');
if($checkbox.is(':checked')) {
$checkboxes.attr("disabled", true);
this.isWellSelected = true;
// Disable all checkboxes but this one
$checkbox.removeAttr("disabled");
} else {
// Enable all checkboxes again
$checkboxes.removeAttr("disabled");
this.isWellSelected = false;
}
}
}
})
}, {
name: "api",
label: "API",
editable: false, // Display only!
cell: "string"
}, {
name: "company",
label: "Operator",
editable: false, // Display only!
cell: "string"
}];

ExtJS 5: Initial ViewModel data not firing formula

I have a ViewModel that contains some initial data... this initial data is based off of a global variable that I have created. In the ViewModel, I have a formula that does some logic based on the data set from the global variable. The interesting thing is, this formula does not fire when the ViewModel is created. I'm assuming this is because the Something.Test property does not exist, so the ViewModel internals have some smarts to not fire the method if that property does not exist.
If the property doesn't exist, how do I fire the formula anyway? I know I could look for Something check to see if it has the property Test, but I'm curious why this example wouldn't work. Here's the example:
Ext.application({
name : 'Fiddle',
launch : function() {
// Define global var Something
Ext.define('Something', {
singleton: true
});
Ext.define('MyViewModel', {
extend: 'Ext.app.ViewModel',
alias: 'viewmodel.myView',
data: {
Something: window.Something
},
formulas: {
testSomething: function(getter) {
console.log('here', getter('Something.Test'));
return getter('Something.Test');
},
myTitle: function(getter) {
return 'My Title';
}
}
});
Ext.define('MyView', {
extend: 'Ext.panel.Panel',
bind: {
title: '{myTitle}'
},
viewModel: {
type: 'myView'
}
});
var view = Ext.create('MyView', {
renderTo: Ext.getBody()
});
// This will fire the ViewModel formula
//view.getViewModel().set('Something', window.Something);
console.log(Something, window.Something)
}
});

You can workout some logic to handle when Something.Test is not available, something like:
data: {
Something: window.Something && window.Something.Test || {Test: null}
},
formulas: {
testSomething: function(get) {
var val = get('Something.Test');
console.log('Test');
return val;
},
myTitle: function(getter) {
return 'My Title';
}
}

Stateful selection in Ext JS

I have a regular tree with elements. What i want to do is following:
When I reload the page, the selected item must be the same as before ( I select only 1 item in the tree).
For example, when I click on 'Sue Potato' - it is selected and when I refresh the page, it must look the same (be also selected).
I've tried reading some Stateful, Provider, Manager on the Sencha Docs, but I didn't get it.
Controller code:
Ext.define('FirstApp.controller.Main', {
extend: 'Ext.app.Controller',
refs: [
{
ref: 'grid',
selector: 'lesson-grid'
},
{
ref: 'tree',
selector: 'school-tree'
}
],
init: function() {
Ext.state.Manager.setProvider(Ext.create('Ext.state.LocalStorageProvider'));
}
});
Tree code:
Ext.define('FirstApp.view.SchoolTree', {
extend: 'Ext.tree.Panel',
xtype: 'school-tree',
stateful: true,
stateId: 'stateGrid',
stateEvents:['selection'],
constructor: function() {
var that = this;
this.store = Ext.create('FirstApp.store.School');
this.store.on('load', function () {
that.getSelectionModel().select(1, true);
});
this.callParent(arguments);
this.getState = function() {
return that.getSelectionModel().getSelection();
};
this.applyState = function() {
};
}
});
Help would be much appreciated.

This is a working code of the requirement above.I had to get an id of the selected element and then pass it to applyState.
Ext.define('FirstApp.view.SchoolTree', {
extend: 'Ext.tree.Panel',
xtype: 'school-tree',
stateful: true,
stateId: 'stateTree',
stateEvents:['selectionchange'],
constructor: function() {
var that = this;
this.store = Ext.create('FirstApp.store.School');
this.store.on('load', function () {
that.getSelectionModel().select(1);
});
this.callParent(arguments);
},
getState: function() {
return {
'stateTree': this.getSelectionModel().getSelection()[0].getId()
};
},
applyState: function(state) {
var me = this;
this.store.on('load', function(record) {
record = this.getById(state.stateTree);
me.getSelectionModel().select(record);
});
}
});

You stored tree state and set it into State Manager
Ext.state.Manager.setProvider(Ext.create('Ext.state.LocalStorageProvider'));
So when you will refresh your page state will apply and an item will be also selected.
Is there any requirement to store state of tree? If yes and still you don't want to selected then you can forcefully clear selection on tree render.

Is there any viewWillAppear like-function in Sencha Touch

I am trying to call a function every time when a view shows up. but it only gets called for first time and thenafter it doesn't. Is there any event-function like viewWillAppear of iOS. I am using 'initialize' event function and it gets called only once. Please help.
View:
Ext.define('Abc.view.abc', {
extend: 'Ext.List',
xtype: 'runningList',
requires: ['Abc.store.InstancesStore','Ext.data.proxy.JsonP',],
config: {
title: 'Running',
id: 'instanceList',/*
itemTpl: '<div class="serached_listview">'+
'<div>{key} {key} </div>' +
'<div><b>{key}</b> </div>' +
'<div> {key}</div>' +
'</div>'
,*/
store: 'RunningInstanceStore',
listeners: [{
fn: 'initialize',
event: 'initialize'
}
]
}
});
Controller:
Ext.define("Abc.controller.InstancesController", {
extend: 'Ext.app.Controller',
requires: [ 'Ext.data.JsonP','Ext.device.Connection'],
config: {
refs: {
main: 'mainpanel',
Instances: '#instanceList',
ListView: 'runningList'
},
control: {
Instances: {
initialize: 'initializePanel',
activate:'initializePanel'
},
"runningInstancesList": {
disclose: 'listViewAccessoryTapped',
itemtap: 'listViewTapped'
}
}
},
listViewAccessoryTapped: function(view, index, item, e) {
if(Ext.device.Connection.isOnline())
console.log('Internet connection is available.');
else
console.log('Internet connection is not available.');
},
listViewTapped: function(view, index, item, e) {
},
initializePanel: function() {
console.log('Hi'); **////////////////Called only once...**
}
});

In ExtJS there is component.beforeactivate, which fires each time before a component is activated
http://docs.sencha.com/ext-js/4-1/#!/api/Ext.AbstractComponent-event-beforeactivate
However, in Touch, there appears to be only container.activate, which looks like it is fired after a child component is activated
http://docs.sencha.com/touch/2-1/#!/api/Ext.Container-event-activate

One of these event handlers (instead of initialize) should help you:
Painted
http://docs.sencha.com/touch/2-1/#!/api/Ext.Component-event-painted
Show
http://docs.sencha.com/touch/2-1/#!/api/Ext.Component-event-show
Ideally these events should be handled in controller like this(one of many ways)
'#instanceList': {
show : 'onListShow'
}
but you can alternatively add listener to your view like this:
Ext.define('Abc.view.abc', {
extend: 'Ext.List',
xtype: 'runningList',
requires: ['Abc.store.InstancesStore','Ext.data.proxy.JsonP',],
config: {
title: 'Running',
id: 'instanceList',
store: 'RunningInstanceStore',
listeners: {
show : function(me, opts){
// Do whatever you want here
}
}
}
});

How to get Ext JS component from DOM element

Trying to create an inline edit form.
I have a form that looks like this:
var editPic = "<img src='https://s3.amazonaws.com/bzimages/pencil.png' alt='edit' height='24' width='24' style='margin-left: 10px;'/>";
var submitPic = "<img id='submitPic' src='https://s3.amazonaws.com/bzimages/submitPic.png' alt='edit' height='24' width='24'/>";
Ext.define('BM.view.test.Edit', {
extend: 'Ext.form.Panel',
alias: 'widget.test-edit',
layout: 'anchor',
title: 'Edit Test',
defaultType: 'displayfield',
items: [
{name: 'id', hidden: true},
{
name: 'name',
fieldLabel: 'Name',
afterSubTpl: editPic,
cls: 'editable'
},
{
name: 'nameEdit',
fieldLabel: 'Name',
xtype: 'textfield',
hidden: true,
cls: 'editMode',
allowBlank: false,
afterSubTpl: submitPic
}
]
});
The controller looks like this (a lot of events):
init: function() {
this.control({
'test-edit > displayfield': {
afterrender: this.showEditable
},
'test-edit': {
afterrender: this.formRendered
},
'test-edit > field[cls=editMode]': {
specialkey: this.editField,
blur: this.outOfFocus
}
});
},
outOfFocus: function(field, event) {
console.log('Lost focus');
this.revertToDisplayField(field);
},
revertToDisplayField: function(field) {
field.previousNode().show();
field.hide();
},
formRendered: function(form) {
Ext.get('submitPic').on('click', function (event, object) {
var field = Ext.get(object).parent().parent().parent().parent();
var cmp = Ext.ComponentQuery.query('test-edit > field[cls=editMode]');
});
},
editField: function(field, e) {
var value = field.value;
if (e.getKey() === e.ENTER) {
if (!field.allowBlank && Ext.isEmpty(value)){
console.log('Not permitted!');
} else {
var record = Ext.ComponentQuery.query('test-edit')[0].getForm().getRecord();
Ext.Ajax.request({
url: '../webapp/tests/update',
method:'Post',
params: {
id: record.getId(),
fieldName: field.name,
fieldValue: field.value
},
store: record.store,
success: function(response, t){
field.previousNode().setValue(value);
t.store.reload();
var text = response.responseText;
// process server response here
console.log('Update successful!');
}
});
}
this.revertToDisplayField(field);
} else if (e.getKey() === e.ESC) {
console.log('gave up');
this.revertToDisplayField(field);
}
},
showEditable: function(df) {
df.getEl().on("click", handleClick, this, df);
function handleClick(e, t, df){
e.preventDefault();
var editable = df.nextNode();
editable.setValue(df.getValue());
editable.show();
editable.focus();
df.hide();
}
},
I'm using the 'afterSubTpl' config to add the edit icon, and the accept icon.
I have listeners set up to listen on click events concerning them, but after they are clicked, I only have the element created by Ext.get('submitPic'). Now I want to have access to the the Ext field and form that surround it. The parent method only brings back other DOM elements. How do I connect between them? You can see what I tried in formRendered.
I hope someone can clarify this little bit for me.

Walk up the DOM tree until you find a component for the element's id:
getCmpFromEl = function(el) {
var body = Ext.getBody();
var cmp;
do {
cmp = Ext.getCmp(el.id);
el = el.parentNode;
} while (!cmp && el !== body);
return cmp;
}
Ext.Component.from(el) does exactly this since ExtJS 6.5.0, as I just learnt. Doc
Source

You can get the component by id, but only if your component and its dom element have the same id (they usually do):
Ext.getCmp(yourelement.id)
But this is not exactly good practice -- it would be better to set up your listeners so that the handler methods already have a reference to the component. For example, in your 'submitPic' component, you could define the click listener like this:
var me = this;
me.on({
click: function(arguments){
var cmp = me;
...
});