I've written a program that includes a form that the user interacts with. Because there are lots of events bound to different buttons I have written a loop that parses some JS that contains the form input information. Here is some example data:
var value = 0,
forms = {
place_controls : {
attrs : {
'class' : 'place-form'
},
input : {
place_x : {
attrs : {
type : 'text',
},
events : {
change : function () {
value = 10;
}
}
},
place_y : {
attrs : {
type : 'text',
},
events : {
change : function () {
value = 50
}
}
}
}
}
}
The data is then parsed by this:
$.each(forms, function (form_index, form) {
var $form_markup = $('<form>').attr(form.attrs);
// Next: loop through each input element of the form we've reached
$.each(form.input, function (element_index, element) {
var $elem = $('<input>').attr(element.attrs);
$elem.appendTo($form_markup);
if (element.events !== undefined) {
$.each(element.events, function (event_index, event) {
$elem.bind(event_index, event);
//$form_markup.on(event_index, $elem, event);
});
}
});
$form_markup.appendTo($form_goes_here);
});
As you can see, I'm using .bind() at the moment, however I want to use .on(). Unfortunately, when I do this all of the items within a form are bound to the last event parsed by the function. When I use .bind() everything works as planned - i.e. Clicking on 'place_x' sets value to 10, clicking 'place_y' sets value to 50.
When using .on(), whichever I change sets value to 50, which I am assuming is because the last function is becoming bound to each event.
Can anybody see what I have done wrong?
Update: There are many different ways to do this, and I have subsequently changed how my code works, however this question is related to why .bind() is working and why .on() is not.
//$elem.bind(event_index, event);
//It looks like you should just be using .on() like this
$elem.on(event_index, event);
The way it looks like you are trying to use .on() is in the live -bubbling- event sort of way, it looks like only the last event you are created is sticking, why each value just gets set to 50.
//$form_markup.on(event_index, $elem, event);
You can create elements with property maps that include handler functions in one simple call:
var $elem = $('<input/>', properties);
The "properties" object can contain event handlers:
var $elem = $('<input/>', {
type: 'text',
name: 'somethingUseful',
click: function(ev) { /* click handler */ },
change: function(ev) { /* change handler */ },
css: { color: "red" }
});
Related
I have an MVC Control for a KendoUI ComboBox that does NOT setup the Change Event ahead of time. Upon rendering, a page controller sets-up & shims-in its' own Change Event.
Oddly, this event gets called TWICE:
When I change the Selected Item
When I click away from the control
Q: What am I doing wrong?
Q: Is this HOW we should over-write the change event on an existing Kendo ComboBox?
MVC CONTROL:
As you can see, I am NOT defining any client-side events here...
#(Html.Kendo().ComboBox()
.Name("ddlTechnician")
.Filter("contains")
.Placeholder("Select Technician...")
.DataTextField("Text")
.DataValueField("Value")
.BindTo(new List<SelectListItem>() {
new SelectListItem() { Text = "Frank", Value = "1" },
new SelectListItem() { Text = "Suzie", Value = "2" },
new SelectListItem() { Text = "Ralph", Value = "3" }
})
.Suggest(true)
.HtmlAttributes(new { style = "width:300px;" }))
PAGE CONTROLLER:
And, I am only defining the event ONCE here. I have also confirmed the event isn't already firing BEFORE setting it in the Page Controller
$(document).ready(function () {
var PageController = (function ($) {
function PageController(options) {
var that = this,
empty = {},
dictionary = {
elements: {
form: null
},
instances: {
ddlTechnician: null
},
selectors: {
form: 'form',
ddlTechnician: '#ddlTechnician'
}
};
var initialize = function (options) {
that.settings = $.extend(empty, $.isPlainObject(options) ? options : empty);
dictionary.elements.form = $(dictionary.selectors.form);
// Objects
dictionary.instances.ddlTechnician = $(dictionary.selectors.ddlTechnician, dictionary.elements.form).data('kendoComboBox');
// Events
dictionary.instances.ddlTechnician.setOptions({ change: that.on.change.kendoComboBox });
};
this.settings = null;
this.on = {
change: {
kendoComboBox: function (e) {
// This is getting called MULTIPLE TIMES
console.log('kendoComboBox RAN');
}
}
}
};
initialize(options);
}
return PageController;
})(jQuery);
var pageController = new PageController({});
});
I was able to reproduce your problem on a Kendo JQuery Combobox when I set the event handler through setOptions, which is not the recommended way after the widget has been rendered. Instead you should use the "bind" method as shown in the documentation's example for change events.
Try changing the line of code where you set your event handler to this:
dictionary.instances.ddlTechnician.bind("change", that.on.change.kendoComboBox);
Here's a dojo that shows the difference: http://dojo.telerik.com/iyEQe
Hope this helps.
I have a kendo Obervable as follows:
var ViewModel = kendo.observable({
ID: 1,
TITLE: "SomeValue",
});
and then I have bound this as follows:
kendo.bind($(".bind-view"), ViewModel );
Now there is button on the page. When clicked I need to check if there are any changes to this ViewModel.
I have tried
$(".ClearAnalysisInfo").on('click', function (event) {
ViewModel.bind("change", function (e) {
//Some code
});
});
But I'm not able to get this ViewModel property whether it changed or not.
Binding the ObservableObject's change event of inside the button's click handler is too late. You need to do that immediately after the ObservableObject is created.
Inside the change handler, you will receive information about the changed field. Use this information to raise some JavaScript flag or save the details you need, so that you can use them later in the button's click handler.
var viewModelChanged = false;
var ViewModel = kendo.observable({
ID: 1,
TITLE: "SomeValue",
});
ViewModel.bind("change", function (e) {
viewModelChanged = true;
});
$(".ClearAnalysisInfo").on('click', function (event) {
if (viewModelChanged) {
// ...
}
});
I have a JQGrid.I need to take some Id to the OnClick function.In my scenario i wanted to get BasicId to the OnClick function.
MyCode
function grid() {
//JqGrid
$('#griddata').html('<table class="table" id="jqgrid"></table>')
$('#jqgrid').jqGrid({
url: '/Admin/GetBasicData/',
datatype: 'json',
mtype: 'GET',
//columns names
colNames: ['BasicId','Images'],
//columns model
colModel: [
{ name: 'BasicId', index: 'BasicId', resizable: false },
{
name: 'Images',
width: 120,
formatter: function () {
return "<button class='btn btn-warning btn-xs' onclick='OpenDialog()' style='margin-left:30%'>View</button>";
}
},
//Some Code here
Open Dialog Function
function OpenDialog(BasicId)
{
//Some code here
}
You can use onclick='OpenDialog.call(this, event)' instead of onclick='OpenDialog()'. You will have this inside of OpenDialog initialized to the clicked <button> and the event.target. Thus your code could be like the following
function OpenDialog (e) {
var rowid = $(this).closest("tr.jqgrow").attr("id"),
$grid = $(this).closest(".ui-jqgrid-btable"),
basicId = $grid.jqGrid("getCell", rowid, "BasicId");
// ...
e.stopPropagation();
}
One more option is even better: you don't need to specify any onclick. Instead of that you can use beforeSelectRow callback of jqGrid:
beforeSelectRow (rowid, e) {
var $td = $(e.target).closest("td"),
iCol = $.jgrid.getCellIndex($td[0]),
colModel = $(this).jqGrid("getGridParam", "colModel"),
basicId = $(this).jqGrid("getCell", rowid, "BasicId");
if (colModel[iCol].name === "Images") { // click in the column "Images"
// one can make additional test for
// if (e.target.nodeName.toUpperCase() === "button")
// to be sure that it was click to the button
// and not the click on another part of the column
OpenDialog(rowid);
return false; // don't select the row - optional
}
}
The main advantages of the last approach: one don't need to make any additional binding (every binding get memory resources and it take time). There are already exist on click handler in the grid and one can use it. It's enough to have one click handler because of event bubbling. The e.target provide us still full information about the clicked element.
Writing js event in your buttons html is not a good idea, its against 'un-obtrusive javasript' principle. You can instead add a click event on the entire grid in the render function and in the callback, filter out based on whether the button was clicked.
//not sure of the syntax of jqgrid, but roughly:
render: function(){
$('#jqgrid').unbind('click').on('click', function(){
if($(e.target).hasClass('btn-warning')){
var tr = $(e.target).parent('tr');
//retrieve the basicId from 'tr'
OpenDialog(/*pass the basicId*/)
}
})
}
Take a look at the following code:
this.dialog({
width: 500,
height: 260,
title: "Setup database",
content: $("<form>").append(table),
buttons: {
submit: function(_alert, dialog) {
dialog.find("form").each(function() {
var arr = $(this).serializeArray();
var data = {
mysql: true
};
var empty = false;
$(this).find("input").removeClass("error");
for (var k in arr) {
if ($.trim(arr[k].value) !== "") {
data[arr[k].name] = arr[k].value;
} else {
empty = true;
$(this).find("input[name='" + arr[k].name + "']").each(function() {
$(this).addClass("error");
});
break;
}
}
if (!empty) {
self.ajax({
url: url,
data: data
}, function(result) {
callback(result);
}, function() {
self.mysql(url, callback, _db_name, _db_user, _db_pass, is_dialog);
});
}
_alert.remove();
if($.isFunction(callback_submit)) {
callback_submit();
}
});
}
}
});
There are two parameters passed into the anonymous function that is supposed to trigger when the button "submit" is clicked. But I have no idea where these parameters are supposed to come from. Can someone explain? Is this related to passing parameters to an anonymous function in Javascript in general?
I don't think you get any argument passed to you when a button event callback is fired on jquery-ui dialog box
http://jsfiddle.net/3d7QC/1577/
buttons: {
"I've read and understand this": function() {
console.log(arguments);
// look at your console
$(this).dialog("close");
}
Only argument you get passed through to you is the customary jQuery event object.
There should only be one parameter passed to submit, which is the event object of the button itself, when clicked. So the context set is the submit button, if you need to access the dialog and modify it, you can do so by accessing the event.target property.
this.dialog({
buttons: {
submit: function(event) {
$(event).dialog('close'); //is the same as...
$(this).dialog('close');
}
});
The first argument _alert is the JS event object that is passed to every event handler in JavaScript. This is not specific to jQuery. javascript.info explains this as follows:
W3C way
Browsers which follow W3C standards always pass the event object as
the first argument for the handler.
For instance:
element.onclick = function(event) {
// process data from event
}
In the jQueryUI API reference they confirm that i
Specifies which buttons should be displayed on the dialog. The context
of the callback is the dialog element; if you need access to the
button, it is available as the target of the event object.
I illustrated this in a fiddle. Not sure what the second argument (dialog in your case) does, though. It's not passed in my example code.
I'm adding the virtual keyboard from http://www.greywyvern.com/code/javascript/keyboard to a text field of an extjs 4.2 form.
It basically works, see here: http://jsfiddle.net/g5VN8/1/
1) My first question is: is this really the best way to connect them? Looks ugly to me with a timer instead of events to keep the extjs value up to date.
Plus I can't overcome the following two issues:
2) the keyboard icon is wrapped to a new line. It should instead be at the end of the field, on the right side, just as in the examples here: http://www.greywyvern.com/code/javascript/keyboard
3) The field focus doesn't work. I have it in a show listener. Even when wrapped in a window.setTimeout() it doesn't work, so it's not a timing issue. No error is thrown.
Here is a copy-paste (stackoverflow's rules). I'll keep both places up to date.
Ext.onReady(function() {
Ext.QuickTips.init();
var formPanel = Ext.create('Ext.form.Panel', {
renderTo: Ext.getBody(),
bodyStyle: 'padding: 5px 5px 0 5px;',
defaults: {
anchor: '100%',
},
items: [{
xtype:'textfield',
name: 'string',
fieldLabel: 'String',
maxLength:30, enforceMaxLength:true,
allowBlank: false,
listeners: {
show: function(field) {
//focus the field when the window shows
field.focus(true, 1000); //TODO: doesn't work, no error
},
afterrender:function(cmp){
cmp.inputEl.set({ //see http://jsfiddle.net/4TSDu/19/
autocomplete:'on'
});
//attach the keyboard
//because it modifies the dom directly we need to hack it to
//inform extjs (really, ext has no such listener option?)
var interval = window.setInterval(function() {
try {
var newValue = cmp.inputEl.dom.value;
var oldValue = cmp.getValue();
if (newValue != oldValue) {
//only do it then, cause it also moves the cursor
//to the end and that sucks.
cmp.setValue( newValue );
}
} catch (e) {
//form was removed
window.clearInterval(interval);
}
}, 100);
// see http://www.greywyvern.com/code/javascript/keyboard
VKI_attach(cmp.inputEl.dom);
}
}
}],
buttons: [{
text: 'Alert string',
handler: function() {
var stringField = this.up('form').getForm().findField('string');
alert(stringField.getValue());
}
}]
});
});
You can attach a listener to the keyboard and when the user clicks on a VKI key you trigger the textfield change event.
Ext.getBody().on({
mousedown: function (ev) {
if (ev.target.tagName === 'TD') {
// We trigger change event only on textfield with the focus
if (document.activeElement) {
if (document.activeElement.id === cmp.inputEl.dom.id) cmp.fireEvent('change');
}
}
},
delegate: '#keyboardInputMaster'
});
This is because ExtJS 4 writes the input field with "style=width:100%".
An easy way is to add a negative margin to the textfield
fieldStyle: 'margin-right:-40px'
Weird ExtJS behaviour. You must focus the input element, not te thextfield component
Ext.defer(function () {
cmp.inputEl.dom.focus();
}, 100);
You can see the whole solution here: http://jsfiddle.net/EGbLn/3/
Avoid timers. Use regular dom event listeners instead.
afterrender: function (cmp) {
...
// simply attach this to the change event from dom element
cmp.inputEl.dom.addEventListener('change', function(){
cmp.setValue(this.value);
});
...
}
(answered already by Samy Rancho)
fieldStyle: 'margin-right:-40px',
Again, avoid timers and anything similar. Simply add this:
afterrender: function (cmp) {
...
//focus on field
cmp.inputEl.dom.focus();
...
}
Find updated fiddle here: http://jsfiddle.net/g5VN8/11/