Changing multiple textboxes with dropdown knockout - javascript

I have the following HTML:
<select id="EmpName" data-bind="value: Employee.EmpName, event: { change: $root.updateEmployee }"></select>
<input disabled type="text" id="EmpNum" data-bind="value: Employee.EmpNum, valueUpdate: 'input'" />
<input disabled type="text" id="EmpClass" data-bind="value: Employee.EmpClass, valueUpdate: 'input'" />
<input disabled type="text" id="EmpDept" data-bind="value: Employee.EmpDept, valueUpdate: 'input' " />
<input disabled type="text" id="EmpStat" data-bind="value: Employee.EmpStat, valueUpdate: 'input'" />
And it's bound by the following ViewModel:
generalViewModel = function (thisData) {
var self = this;
this.Incident = ko.mapping.fromJS(thisData.Incident);
this.Employee = ko.mapping.fromJS(thisData.Employee);
this.updateEmployee = function () {
var employeeName = self.Employee.EmpName;
$.getJSON('/Incidents/GetEmployee', { EmployeeName: employeeName }, function (data, status, xhr) {
var newEmp = ko.mapping.fromJS(data);
self.Employee(newEmp);
});
}
this.refreshData = function (incID) {
GetIncidentGeneralInfo(incID, node);
}
this.savetoServer = function (incID, buttonID) {
var incident = ko.toJSON(self.Incident);
var employee = ko.toJSON(self.Employee);
$.post('/Incidents/SaveIncident', { IncidentID: incID, JSONIncident: incident, JSONEmployee: employee, button: buttonID }, function (data, status, xhr) {
self.refreshData(data);
});
}
}
ko.applyBindings(new generalViewModel(data), document.getElementById(node));
Everything is working quite nicely, with the exception of the updateEmployee function. The JSON is returning the new Employee information, but the textboxes aren't updating. I'm doing something silly incorrectly, and I can't quite figure out wat

Instead of
var newEmp = ko.mapping.fromJS(data);
self.Employee(newEmp);
You should do
ko.mapping.fromJS(data, self.Employee);
This will update all of the observable properties on self.Employee that were created by the first call to ko.mapping.fromJS.

Related

knockoutjs using module pattern not working

I am trying to create simple knockout example using module pattern
var login = {}; //login namespace
//Constructor
login.UserData = function () {
var self = this;
self.UserName = ko.observable("");
self.Password = ko.observable("");
};
//View-Model
login.UserVM = function () {
this.userdata = new login.UserData(),
this.apiUrl = 'http://localhost:9090/',
this.authenticate = function () {
var data = JSON.parse(ko.toJSON(this.userdata));
var service = apiUrl + '/api/Cryptography/Encrypt';
DBconnection.fetchdata('POST', service, JSON.stringify(data.Password), response, function () { console.log('Cannot fetch data') }, null, true);
function response(res) {
console.log(res)
}
}
return {
authenticate: this.authenticate
}
}();
$(function () {
ko.applyBindings(login.UserVM); /* Apply the Knockout Bindings */
});
HTML CODE:
<form id="loginform" name="loginForm" method="POST">
<div id="form-root">
<div>
<label class="form-label">User Name:</label>
<input type="text" id="txtFirstName" name="txtFirstName" data-bind="value:login.UserData.UserName" />
</div>
<div>
<label class="form-label">Password:</label>
<input type="text" id="txtLastName" name="txtLastName" data-bind="value:login.UserData.Password" />
</div>
<div>
<input type="button" id="btnSubmit" value="Submit" data-bind="click: authenticate" />
</div>
</div>
</form>
the problem is am not able to get userdata in the viewmodel on click of submit it is returning undefined and the login object holds the changed value of textbox but on click it is returning black values.
please let me know
Also can you let me know how to implement definative module pattern in the same code.
The object you are returning from login.UserVM has only authenticate property and doesn't have userdata or apiUrl properties. So, instead using an IIFE to create an object, set login.UserVM to a constructor function similar to login.UserData. And then use new operator to create the viewModel object. Now the viewModel will have userdata and apiUrl properties (remove the return from the function)
Also, you need to change the HTML bindings to: data-bind="value:userdata.UserName". This looks for the userdata property inside the bound viewModel
var login = {}; //login namespace
//Constructor
login.UserData = function () {
var self = this;
self.UserName = ko.observable("");
self.Password = ko.observable("");
};
//View-Model
login.UserVM = function () {
this.userdata = new login.UserData(),
this.apiUrl = 'http://localhost:9090/',
this.authenticate = function () {
var data = JSON.parse(ko.toJSON(this.userdata));
console.log(data)
//var service = this.apiUrl + '/api/Cryptography/Encrypt';
//DBconnection.fetchdata('POST', service, JSON.stringify(data.Password), response, function () { console.log('Cannot fetch data') }, null, true);
function response(res) {
console.log(res)
}
}
}; // remove the () from here
ko.applyBindings(new login.UserVM()); /* Apply the Knockout Bindings */
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-min.js"></script>
<form id="loginform" name="loginForm" method="POST">
<div id="form-root">
<div>
<label class="form-label">User Name:</label>
<input type="text" id="txtFirstName" name="txtFirstName" data-bind="value:userdata.UserName" />
</div>
<div>
<label class="form-label">Password:</label>
<input type="text" id="txtLastName" name="txtLastName" data-bind="value:userdata.Password" />
</div>
<div>
<input type="button" id="btnSubmit" value="Submit" data-bind="click: authenticate" />
</div>
</div>
</form>

Updating knockout variable value

I have the below model
var CountryScopeVM = function (data, root) {
CountryScopeVM.call(this, data);
var self = this;
this.isSelected = ko.observable();
this.centralImpLowHeadCount = ko.observable();
this.load(data);
}
};
this.countryScopes = ko.observableList(CountryScopeVM, data.countryScopes, this);
And I have the below code which gets called when a checkbox is selected. What I am trying to do here is have all the centralImpLowHeadCount inside the countryscope array get updated when the main checkbox is checked but it is not updating and I don't see the change in the UI.
selectAllLOWImplementation: function (data, event) {
var select = $(event.target).is(':checked');
ko.utils.arrayForEach(model.countryScopes() || [], function (countryScope) {
countryScope().centralImpLowHeadCount == select;
});
return true;
}
HTML
<input type="checkbox" data-bind="checked: hasSelectedLOWImplementation, click: selectAllLOWImplementation" />
<td><input type="checkbox" data-bind="checked: centralImpLowHeadCount, enable: isOn" /></td>

knockoutjs radio button checked value with protectedobservable

thank you for looking into this.
I have the following example built: http://jsfiddle.net/zm381qjx/5/
This is a menu list builder. When you add a menu, an edit form pops up. Using protectedObservable so that i can either commit or reset (as per code). One functionality, which i am having problems with, is there is radio button list (for TypeId), and depending on the value (10 = Url, 20 = Category, 30 = Page), you set the respective properties (10 = Url, 20 = CategoryId, 30 = PageId).
Flicking through the radio buttons, if Url is selected, another textbox should show (based on urlVisible) so user can enter the Url. I have added a span with text: TypeId.temp so i can see the temporary value. This is very irregular. Try to flick through several times.
Any help will be greatly appreciated.
My HTML
<a class="btn btn-primary" data-bind="click: addMenu">Add Menu</a>
<ul data-bind="foreach: Menus">
<li></li>
</ul>
<div class="panel panel-default" data-bind="slideIn: editMenuItem, with: editMenuItem">
<div class="panel-body">
<div class="form-group">
<label for="MenuName">Name: </label>
<input type="text" id="MenuName" data-bind="value: Name" class="form-control" />
</div>
<label class="radio-inline">
<input type="radio" name="MenuTypeId" value="10" data-bind="checked: TypeId" /> Url
</label>
<label class="radio-inline">
<input type="radio" name="MenuTypeId" value="20" data-bind="checked: TypeId" /> Category
</label>
<label class="radio-inline">
<input type="radio" name="MenuTypeId" value="30" data-bind="checked: TypeId" /> Page
</label>
<div class="form-group" data-bind="visible: urlVisible">
<label for="MenuUrl">Url: </label>
<input type="text" id="MenuUrl" data-bind="value: Url" class="form-control" />
</div>
<br />
<p>TypeId.temp = <span data-bind="text: TypeId.temp"></span></p>
<br /><br />
<input type="button" class="btn btn-success" value="Update" data-bind="click: commit" /> or
Cancel
</div>
</div>
My JS:
var vm = null;
//wrapper for an observable that protects value until committed
ko.protectedObservable = function (initialValue) {
//private variables
var _temp = ko.observable(initialValue);
var _actual = ko.observable(initialValue);
var result = ko.dependentObservable({
read: function () {
return _actual();
},
write: function (newValue) {
_temp(newValue);
}
});
//commit the temporary value to our observable, if it is different
result.commit = function () {
var temp = _temp();
if (temp !== _actual()) {
_actual(temp);
}
};
//notify subscribers to update their value with the original
result.reset = function () {
_actual.valueHasMutated();
_temp(_actual());
};
result.temp = _temp;
return result;
};
ko.bindingHandlers.slideIn = {
init: function (element) {
$(element).hide();
},
update: function (element, valueAccessor) {
var value = ko.utils.unwrapObservable(valueAccessor());
if (value) {
$(element).stop().hide().slideDown('fast');
} else {
$(element).stop().slideUp('fast');
}
}
};
var Menu = function (Id, Name, TypeId, CategoryId, PageId, Url) {
var self = this;
/* Core Properties */
self.Id = ko.observable(Id);
self.Name = ko.protectedObservable(Name);
self.TypeId = ko.protectedObservable(TypeId);
self.CategoryId = ko.protectedObservable(CategoryId);
self.PageId = ko.protectedObservable(PageId);
self.Url = ko.protectedObservable(Url);
/* Virtual Properties */
self.urlVisible = ko.computed(function () {
return self.TypeId.temp() == "10";
}, self);
/* Virtual Functions */
self.editMenu = function (data) {
if(vm.editMenuItem()) {
vm.editMenuItem(null);
}
vm.editMenuItem(data);
};
/* Core Functions */
self.commit = function () {
if (self.Name.temp() == '' || self.Name.temp() == null) {
alert('Please enter a name.'); return;
}
self.Name.commit();
self.TypeId.commit();
self.CategoryId.commit();
self.PageId.commit();
self.Url.commit();
vm.editMenuItem(null);
};
self.reset = function () {
self.Name.reset();
self.TypeId.reset();
self.CategoryId.reset();
self.PageId.reset();
self.Url.reset();
vm.editMenuItem(null);
};
};
var ViewModel = function() {
var self = this;
/* Core Properties */
self.Menus = ko.observableArray([]);
/* Virtual Properties */
self.editMenuItem = ko.observable(null);
self.addMenu = function(){
var menu = new Menu(0, "New Menu", "10", 0, 0, "");
self.Menus.push(menu);
self.editMenuItem(menu);
};
};
$(function () {
vm = new ViewModel();
ko.applyBindings(vm);
});
If you change your radio button binding to
<input type="radio" name="MenuTypeId" value="10" data-bind="checked: TypeId.temp" />
The temp id will be changed accordingly and radio button behaviour is consistent, but not with TypeId as value.
also the protectedObservable binding the radio button value is not playing nice
When you manually click the radio the TypeId value is never changed (as you are not committing the value) and I guess that as the radio button value never changes from 10 , it is not recognizing the subsequent manual clicks on Url radio button.
I updated the value using a button and it is changing accordingly; but then it will not move the value from that TypeId on subsequent radio button clicks
And the problem is still appearing for protectedObservable binding but not with a simple observable.
Code which explores this idea further: http://jsfiddle.net/zm381qjx/101/

Disable input only when modified by system

This code does a search and displays the results. I want to conditionally disable inputs.I am using knockout to control when an input is disabled.
Requirement:
input is disabled when set by the system.
User input should not be disabled.
In the following code input that comes from readDatabase() works well. If the user types in the Hometown/Nickname inputthen tabs out then input disables. How can I fix this code to meet the second requirment?
Update
I am not opposed to getting some help from jQuery. I do not want to throw out my view model binding entirely.
Fiddle
HTML
Name: <input type="text" data-bind="value: userInput, valueUpdate: 'input'" /><br />
Hometown: <input type="text" data-bind="value: Hometown, disable: Hometown" /><br />
NickName: <input type="text" data-bind="value: Address, disable: Address" />
JavaScript
function MyViewModel() {
var self = this;
self.userInput = ko.observable();
self.Hometown = ko.observable();
self.Address = ko.observable();
self.userInput.subscribe(function () {
readDatabase(self);
});
}
ko.applyBindings(new MyViewModel());
function readDatabase(self){
if(self.userInput().substring(0,1) == "a"){
self.Hometown("A town");
self.Address("A address");
}
else {
self.Hometown("");
self.Address("Other address");
}
}
You could use an extender to provide a flag indicating where the data came from:
ko.extenders.isServerSet = function (target, value) {
target.isServerSet = ko.observable(value);
return target;
};
function MyViewModel() {
var self = this;
self.userInput = ko.observable();
self.Hometown = ko.observable().extend({
isServerSet: false
});;
self.Address = ko.observable().extend({
isServerSet: false
});;
self.userInput.subscribe(function () {
readDatabase(self);
});
}
ko.applyBindings(new MyViewModel());
function readDatabase(self) {
if (self.userInput().substring(0, 1) == "a") {
// don't overwrite user-provided values
if (!self.Hometown()) {
self.Hometown("A town");
self.Hometown.isServerSet(true);
}
if (!self.Address()) {
self.Address("A address");
self.Address.isServerSet(true);
}
} else {
self.Hometown("");
self.Address("Other address");
}
}
Name: <input type="text" data-bind="value: userInput, valueUpdate: 'input'" /><br />
Hometown: <input type="text" data-bind="value: Hometown, disable: Hometown.isServerSet" /><br />
NickName: <input type="text" data-bind="value: Address, disable: Address.isServerSet" />
Updated fiddle

Knockout.js enable save only if value change

I have a simple html page with value input and save button.
I want the save will be enabled only if the value is changed (somtimes is initialized and somtimes not.
I've tryied few things without any success
HTML
<input type="text"
placeholder="type here"
data-bind="value: rate,"/>
<button data-bind="click: save">Save</button>
JS
var viewmodel = function () {
this.rate = ko.observable('88').extend(required: true);
};
viewmodel.prototype.save = function () {
alert('save should be possible only if rate is changed);
};
Also on jsfiddle
Should be able to achieve this with a computed observable and the enable binding.
See http://jsfiddle.net/brendonparker/xhLrB/1/
Javascript:
var ctor = function () {
var self = this;
self.originalRate = '88';
self.rate = ko.observable('');
self.canSave = ko.computed(function(){
return self.originalRate == self.rate();
});
};
ctor.prototype.save = function () {
alert('save should be possible only if rate is changed');
};
ko.applyBindings(new ctor());
HTML:
<input type="text" placeholder="type here" data-bind="value: rate, valueUpdate: 'afterkeydown'"/>
<button data-bind="click: save, enable: canSave">Save</button>

Categories