knockout click event - javascript

I have the following code:
<div class="icon-upload" data-bind="click: button('upload') "> Upload </div>
ko.bindingHandlers.button = {
init: function(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext)
{
//alert('works');
console.log(element);
}
};
But I keep getting a button is not defined error. I'm trying to do an on('click') event with a parameter to determine latter what binding to initialize.
For example, when clicking on button('upload') I want to initialize the following binding
ko.bindingHandlers.image = {
init: function (element, valueAccessor, allBindingsAccessor, context)
{
var value = ko.utils.unwrapObservable(valueAccessor()),
$element = $(element);
console.log($element)
$element.html(value);
/*$element.pluploadQueue({
runtime: 'gears, browserplus, html5, flash, html4',
max_file_size: '10mb',
max_file_count: 10,
chunk_size: '1mb',
unique_names: true,
multiple_queues: true,
drop_element: true,
dragdrop: true,
filters : [
{title : "Image files", extensions : "jpg,gif,png"}
]
});*/
}
};
Do I must wrap the click code in a ViewModel = function() { like in
http://jsfiddle.net/jearles/xSKyR/
http://jsfiddle.net/FpSWb/ ?
Can't I do it the way I'm trying to do it?

You doing it wrong. You should create custom binding button which will be triggered on click event.
ko.bindingHandlers.button = {
init: function (element) {
$(element).click(function() {
// Your logic
});
}
update: function(element, valueAccessor, allBindingsAccessor) {
switch(ko.utils.unwrapObservable(valueAccessor())) {
case 'upload': ...
}
}
}
In view
<div class="icon-upload" data-bind="button: 'upload'"> Upload </div>

Related

Creating advanced KnockOut binding handler for google.visualization.datatable

Thanks to this tutorial I managed to create a KnockOut binding handler for Google's DataTable.
This is my binding handler, so far:
ko.bindingHandlers.dataTable = {
init: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
var table = new google.visualization.Table(element);
ko.utils.domData.set(element, "dataTable", table);
},
update: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
var value = ko.unwrap(valueAccessor());
// Get options:
var options = allBindings.get("tableOptions") || {};
// Default options:
options.width = options.width || "200px";
options.height = options.height || "200px";
options.showRowNumber = options.showRowNumber || false;
// Get events:
var onSelected = allBindings.get("select") || false;
if (onSelected) {
$(element).on("select", function(event, ui) {
valueAccessor()(ui.value);
});
}
var table = ko.utils.domData.get(element, "dataTable");
table.draw(value, options);
}
};
This is my HTML part:
<div data-bind="dataTable: $root.getData(), tableOptions: {width: '100%',height: '200px', 'allowHtml': true, 'cssClassNames': {'selectedTableRow': 'orange-background'} }"></div>
So far I get a table with fixed headers which works just fine.
Now I want to extent to binding handler to react on the 'select row' event.
I tried this using the // Get events section in my handler but this is not working.
In my HTML I add select: $root.selectedRow(),
In my function selectedRow() I put a console.log("In selectedRow"). When I load the page I see selectedRow is called for every row, but when I click on a row it is not called.
The row its background is changed to orange, so Google is adding the selectedTableRow class.
How to wrap/bind to the select event?
The main thing that's going wrong is, if I'm not mistaken, the way you're trying to attach your event listener.
Your $(element).on("select", onSelect) is not how the library you're using attaches event listeners. In the documentation you can see that you actually need to use: google.visualization.events.addListener(table, 'select', selectHandler);
Additionally, it's better to attach the event listener in the init method. update is called whenever your data changes, so it might add multiple event listeners.
Here's a working example of your code:
google.charts.load('current', {
'packages': ['table']
});
google.charts.setOnLoadCallback(function() {
ko.bindingHandlers.dataTable = {
init: function(element, valueAccessor, allBindings, viewModel, bindingContext) {
var table = new google.visualization.Table(element);
ko.utils.domData.set(element, "dataTable", table);
// Get events:
var onSelected = allBindings.get("select") || false;
if (onSelected) {
google.visualization.events.addListener(table, 'select', function() {
// TODO: null/undefined/multiple selection checks
var data = valueAccessor();
var row = table.getSelection()[0].row;
onSelected(data.getValue(row, 1)); // Sends salary of clicked row
});
}
},
update: function(element, valueAccessor, allBindings, viewModel, bindingContext) {
var value = ko.unwrap(valueAccessor());
// Get options:
var options = allBindings.get("tableOptions") || {};
// Default options:
options.width = options.width || "200px";
options.height = options.height || "200px";
options.showRowNumber = options.showRowNumber || false;
var table = ko.utils.domData.get(element, "dataTable");
table.draw(value, options);
}
};
ko.applyBindings({
onSelect: function(value) {
alert(value);
},
getData: function() {
var data = new google.visualization.DataTable();
data.addColumn('string', 'Name');
data.addColumn('number', 'Salary');
data.addColumn('boolean', 'Full Time Employee');
data.addRows([
['Mike', {
v: 10000,
f: '$10,000'
},
true
],
['Jim', {
v: 8000,
f: '$8,000'
},
false
],
['Alice', {
v: 12500,
f: '$12,500'
},
true
],
['Bob', {
v: 7000,
f: '$7,000'
},
true
]
]);
return data;
}
})
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<div data-bind="dataTable: getData(), tableOptions: {width: '100%',height: '200px', 'allowHtml': true, 'cssClassNames': {'selectedTableRow': 'orange-background'} }, select: onSelect"></div>

Allow user to self define the selected value in a select using Select2 and Knockout

Select2 allows to improve standard <select> by applying on some style and feature.
I have to display Select2 styled dropdown list, custom binded with Knockout.
It is a phone number list, and user could add some entries.
I want it to be editable.
The user should be able to select an entry or type a new one wich can be used in the application (binded with manager.selectedPhoneNumber)
So, in the HTML:
<body>
<select id="list" data-bind="
options: manager.getMyPhoneNumbers(),
optionsValue: 'id',
optionsText: 'text',
customBinding_phoneNumbersEditableList: manager.selectedPhoneNumber
">
</select>
</body>
And in Javascript:
ko.bindingHandlers.customBinding_phoneNumbersEditableList = {
init: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
// initialize select2 with binded element
$(element).select2({
//createSearchChoice: function (term, data) {
// if ($(data).filter(function () {
// return this.text.localeCompare(term) === 0;
// }).length === 0) {
// return {
// id: term,
// text: term
// };
// }
//},
formatResult: function (item) {
return buildSomePrettyString();
},
formatSelection: function (item) {
return buildSomePrettyString();
},
sortResults: function (results, container, query) {
return results;
}
});
},
update: function (element, valueAccessor, allBindings, viewModel, bindingContext) { }
};
Uncomment the function createSearchCoice does not work. It causes an exception Error: Option 'createSearchChoice' is not allowed for Select2 when attached to a <select> element.
Someone could help me ?

Update jquery DataTable when Knockout ViewModel change

I have a Datatable that takes data from Knockout ViewModel array. New rows are added fine when I push new objects to the array, but when an object in that array is changed, the row isn't being updated.
The relecent ViewModel code:
.....
self.Products = ko.observableArray();
.....
Sample data (e.g result of ko.toJSON(VM.Products()) ):
"[
{"Price":"114.28","Name":"Pearls","Description":"Little and big","Quantity":3},
{"Price":"117.55","Name":"Silver","Description":"Sliver Coins","Quantity":2},
{"Price":"166.09","Name":"Phone","Description":"Nokia","Quantity":2},
{"Price":"169.36","Name":"Wood","Description":"Northen forest wood","Quantity":1}
]"
Then Datatable code:
var CartDt = $("#PurchasedPrdTbl").DataTable({
pageLength: 5,
aoData: ko.toJSON(VM.Products()),
columns: [
{ "title": 'Price' },
{ "title": 'Name' },
{ "title": 'Description' },
{ "title": 'Quantity' },
{
"className": 'remove-details-control',
"orderable": false,
"data": null,
"defaultContent": '',
"title": "Sell Me!",
"fnRender": function (oObj) {
return oObj.aData;
}
}
]
});
I'v tried ajax.reload but it didn't helped.
Any ideas would be great, thanks.
EDIT:
I'm trying fnUpdate (source) like this:
CartDt.fnUpdate([{"Price":"114.28","Name":"Pearls","Description":"Little and big","Quantity":3}],1);
But I get this:
Uncaught TypeError: undefined is not a function
This is because the html that is bound to your knockout observable array is mangled when datatables is initialized... The html is copied and reformatted to be "datatables" after initialization. so the elements that you view after datatables initialization are not the same elements that knockout has bound to. I have created a custom binding to use datatables with knockout. it is dependent upon a fork of knockout which adds before render all and after render all events. I have created a pull request with the knockout git hub repository. If the below solution helps you please leave a comment on the pull request to get it merged into knockout 3.4... thanks.
fiddle of working solution
my pull request
ko.bindingHandlers.DataTablesForEach = {
init: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
var nodes = Array.prototype.slice.call(element.childNodes, 0);
ko.utils.arrayForEach(nodes, function (node) {
if (node && node.nodeType !== 1) {
node.parentNode.removeChild(node);
}
});
return ko.bindingHandlers.foreach.init(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext);
},
update: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
var value = ko.unwrap(valueAccessor()),
key = "DataTablesForEach_Initialized";
var newValue = function () {
return {
data: value.data || value,
beforeRenderAll: function (el, index, data) {
if (ko.utils.domData.get(element, key)) {
$(element).closest('table').DataTable().clear();
$(element).closest('table').DataTable().destroy();
}
},
afterRenderAll: function (el, index, data) {
$(element).closest('table').DataTable(value.options);
}
};
};
ko.bindingHandlers.foreach.update(element, newValue, allBindingsAccessor, viewModel, bindingContext);
//if we have not previously marked this as initialized and there is currently items in the array, then cache on the element that it has been initialized
if (!ko.utils.domData.get(element, key) && (value.data || value.length)) {
ko.utils.domData.set(element, key, true);
}
return { controlsDescendantBindings: true };
}
};

Knockout Binding Handlers undefined error

I have this jsfiddle which shows a table and some users with roles.
I want to have a modal form pop up when some clicks add roles etc.
There seems to be an error on the update property of this ko.bindingHandlers.modal function:
ko.bindingHandlers.modal = {
init: function (element, valueAccessor) {
$(element).modal({ show: false }).on("hidden", function () {
var data = valueAccessor();
if (ko.isWriteableObservable(data))
data(null);
});
return ko.bindingHandlers["with"].init.apply(this, arguments);
},
update: function (element, valueAccessor) {
var data = ko.unwrap(valueAccessor());
$(element).modal( data ? "show" : "hide" );
return ko.bindingHandlers["with"].update.apply(this, arguments); // Error on this line
}
};
I don't why this is happening, I have copied the code from Ryan Niemeyer dev video
Its 34mins in.
It's a Bootstrap modal dialogue, using Knockout JS as the binding library
The with binding does no longer have the update function
From the init function use
ko.applyBindingsToNode(element, { with: valueAccessor() });
Update
ko.bindingHandlers.modal = {
init: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
$(element).modal({ show: false }).on("hidden", function () {
var data = valueAccessor();
if (ko.isWriteableObservable(data))
data(null);
});
ko.applyBindingsToNode(element, { with: valueAccessor() }, bindingContext);
return { controlsDescendantBindings: true };
},
update: function (element, valueAccessor) {
var data = ko.unwrap(valueAccessor());
$(element).modal( data ? "show" : "hide" );;
}
};

Knockout DatePicker bound item doesn't disable the DatePicker

I have a custom knockoutJs binding for the date picker.
ko.bindingHandlers.valueAsDatePicker = {...}
When the bound input field status (enabled/disabled) is bound to a KO observable it doesn't enable/disable the datepicker icon.
HTML
<input id="txtRequestedTo" type="text" placeholder="dd/mm/yyyy"
data-bind="valueAsDatePicker: reqDateTo, disable: reqDateFrom().length < 1" />
Custom Binding
ko.bindingHandlers.valueAsDatePicker = {
init: function(element, valueAccessor, allBindingsAccessor) {
ko.bindingHandlers.value.init(element, valueAccessor, allBindingsAccessor);
formatAndSetDateValue(element, valueAccessor, allBindingsAccessor);
// Init UI datepicker
var dateFormat = allBindingsAccessor.dateFormat
$(element).datepicker({
dateFormat: dateFormat,
changeMonth: true,
changeYear: true,
yearRange: '1900:' + new Date().getFullYear(),
maxDate: 0,
showOn: "button",
buttonImage: "Content/images/sprite-base/sprite/icon-calender.png",
buttonImageOnly: true,
constrainInput: false,
buttonText: ""
});
},
update: function(element, valueAccessor, allBindingsAccessor) {
// Use the value binding
ko.bindingHandlers.value.update(element, valueAccessor, allBindingsAccessor);
formatAndSetDateValue(element, valueAccessor, allBindingsAccessor);
valueAccessor().valueHasMutated();
}
};
I want the datepicker to be disabled if the element is disabled, and Vice Versa.
Thanks a million Robert,
Here is the solution that worked.
Using KnockOutJS V3.1
init: function (element, valueAccessor, allBindings) {
...
//Disable the datepicker if the item is disabled or enabled.
if (allBindings.has('disable')) {
if (allBindings.get('disable')()) {
$(element).datepicker('disable');
}
else {
$(element).datepicker('enable');
}
var subscription = allBindings.get('disable').subscribe(function (newValue) {
if (newValue) {
$(element).datepicker('disable');
} else {
$(element).datepicker('enable');
}
});
ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
subscription.dispose();
});
}
}
You have to use
if (allBindings.has('disable')) {
otherwise
allBindings.get('disable')
will be undefined as not all datepicker bound fields in the view have the disabled attribute.
The trick here is to get access to the disabled binding as an observable so you can attach a manual subscription. At the moment the result of the disable expression is passed into bindingHandler ( via allBindingAccessor ).
One you get a subscription you can invoke DatePicker's disable option
HTML
<input id="txtRequestedTo" type="text" placeholder="dd/mm/yyyy"
data-bind="valueAsDatePicker: reqDateTo, disable: reqDateFrom.disabled" />
JAVASCRIPT
var reqDateFrom = ko.observable();
var reqDateTo = ko.observable();
reqDateTo.disabled = ko.computed( function() {
return (reqDateFrom() || '').length === 0;
} );
ko.bindingHandlers.valueAsDatePicker {
init: function(element, valueAccessor, allBindingsAccessor) {
....
// ko 3.0 syntax. For 2.x use allBindingAccessor['disable']
var subscription = allBindingAccessor.get('disable').subscribe( function(newValue) {
$(element).datepicker('option', 'disabled', newValue);
});
// Make sure the subscription is disposed when the element is torn down
ko.utils.domNodeDisposal.addDisposeCallback(element, function() {
subscription.dispose();
});
},
update: function(element, valueAccessor, allBindingsAccessor) {
}
}

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