I have my knockout page hub, and I need a ko.obeservableArray nested in a ko.observable object, this is where I define them:
function IncomeDeclarationHub() {
//data comes from a ajax call.
self.myIncomeDeclarationViewModel = ko.observable(new IncomeDeclarationViewModel(data));
}
function IncomeDeclarationViewModel(data) {
var self = this;
self.retentionAmount = ko.observable();
self.taxableMonth = ko.observable();
self.incDecDetGroViewModels = ko.observableArray();
if (data != null) {
var arrayLenght = data.IncDecDetGroViewModels.length;
for (var i = 0; i < arrayLenght; i++) {
var myObject = new IncomeDecDetGroViewModel(data.IncDecDetGroViewModels[i]);
self.incDecDetGroViewModels.push(myObject);
}
}
}
And this is my HTML code:
<span class="label">
Retention Amount
</span>
<input data-bind="value: myIncomeDeclarationViewModel.retentionAmount" />
<table>
<tbody data-bind="foreach: myIncomeDeclarationViewModel.incDecDetGroViewModels">
...
</tbody>
</table>
Ok so the thing is that incDecDetGroViewModels never gets populated, I used to have that ko.obersableArray outside the object, and it worked fine, now that I inserted it in my object myIncomeDeclarationViewModel is not populating the html table. Do I need to call it in a different way at the data-bind
myIncomeDeclarationViewModel is an observable, so you have to unwrap it to access it's properties. Add parenthesis to unwrap it (access the observable's underlying value) like this:
<span class="label">
Retention Amount
</span>
<input data-bind="value: myIncomeDeclarationViewModel().retentionAmount" />
<table>
<tbody data-bind="foreach: myIncomeDeclarationViewModel().incDecDetGroViewModels">
...
</tbody>
</table>
Here's a working jsFiddle based on your example
JsFiddle
well previously you can access just becoz it is in scope but right now you done some nesting so you just need to some looping in your view part to get that .
Something like this may be :
<table data-bind="foreach:myIncomeDeclarationViewModel">
<tbody data-bind="foreach:$data.incDecDetGroViewModels">
...
</tbody>
</table>
You can also ContainerLess foreach if you looking for something different like :
<!-- ko foreach:myIncomeDeclarationViewModel -->
//your table code
<!--/ko-->
I hope this solves the riddle .
Related
I have a multi dropdown list and I need to do the following:
1. Make sure that when selecting value in one dropdown list it won't appear in the others (couldn't find a proper solution here).
2. When selecting the value "Text" a text field (<input>) will apear instead of the Yes/no dropdown.
3. "Choose option" will appear only for the first row (still working on it).
4. Make sure that if "Text" is selected, it always will be on the top (still working on it).
JSFiddle
HTML:
<div class='liveExample'>
<table width='100%'>
<tbody data-bind='foreach: lines'>
<tr>
<td>
Choose option:
</td>
<td>
<select data-bind='options: filters, optionsText: "name", value: filterValue'> </select>
</td>
<td data-bind="with: filterValue">
<select data-bind='options: filterValues, optionsText: "name", value: "name"'> </select>
</td>
<td>
<button href='#' data-bind='click: $parent.removeFilter'>Remove</button>
</td>
</tr>
</tbody>
</table>
<button data-bind='click: addFilter'>Add Choice</button>
JAVASCRIPT:
var CartLine = function() {
var self = this;
self.filter = ko.observable();
self.filterValue = ko.observable();
// Whenever the filter changes, reset the value selection
self.filter.subscribe(function() {
self.filterValue(undefined);
});
};
var Cart = function() {
// Stores an array of filters
var self = this;
self.lines = ko.observableArray([new CartLine()]); // Put one line in by default
// Operations
self.addFilter = function() { self.lines.push(new CartLine()) };
self.removeFilter = function(line) { self.lines.remove(line) };
};
ko.applyBindings(new Cart());
I will appeaciate your assist here! Mainly for the first problem.
Thanks!
Mike
If you want to limit the options based on the options that are already selected in the UI, you'll need to make sure every cartLine gets its own array of filters. Let's pass it in the constructor like so:
var CartLine = function(availableFilters) {
var self = this;
self.availableFilters = availableFilters;
// Other code
// ...
};
You'll have to use this new viewmodel property instead of your global filters array:
<td>
<select data-bind='options: availableFilters,
optionsText: "name",
value: filterValue'> </select>
</td>
Now, we'll have to find out which filters are still available when creating a new cartLine instance. Cart manages all the lines, and has an addFilter function.
self.addFilter = function() {
var availableFilters = filters.filter(function(filter) {
return !self.lines().some(function(cartLine) {
var currentFilterValue = cartLine.filterValue();
return currentFilterValue &&
currentFilterValue.name === filter.name;
});
});
self.lines.push(new CartLine(availableFilters))
};
The new CartLine instance gets only the filter that aren't yet used in any other line. (Note: if you want to use Array.prototype.some in older browsers, you might need a polyfill)
The only thing that remains is more of an UX decision than a "coding decision": do you want users to be able to change previous "Choices" after having added a new one? If this is the case, you'll need to create computed availableFilters arrays rather than ordinary ones.
Here's a forked fiddle that contains the code I posted above: http://jsfiddle.net/ztwcqL69/ Note that you can create doubled choices, because choices remain editable after adding new ones. If you comment what the desired behavior would be, I can help you figure out how to do so. This might require some more drastic changes... The solution I provided is more of a pointer in the right direction.
Edit: I felt bad for not offering a final solution, so here's another approach:
If you want to update the availableFilters retrospectively, you can do so like this:
CartLines get a reference to their siblings (the other cart lines) and create a subscription to any changes via a ko.computed that uses siblings and their filterValue:
var CartLine = function(siblings) {
var self = this;
self.availableFilters = ko.computed(function() {
return filters.filter(function(filter) {
return !siblings()
.filter(function(cartLine) { return cartLine !== self })
.some(function(cartLine) {
var currentFilterValue = cartLine.filterValue();
return currentFilterValue &&
currentFilterValue.name === filter.name;
});
});
});
// Other code...
};
Create new cart lines like so: self.lines.push(new CartLine(self.lines)). Initiate with an empty array and push the first CartLine afterwards by using addFilter.
Concerning point 2: You can create a computed observable that sorts based on filterValue:
self.sortedLines = ko.computed(function() {
return self.lines().sort(function(lineA, lineB) {
if (lineA.filterValue() && lineA.filterValue().name === "Text") return -1;
if (lineB.filterValue() && lineB.filterValue().name === "Text") return 1;
return 0;
});
});
Point 3: Move it outside the foreach.
Point 4: Use an if binding:
<td data-bind="with: filterValue">
<!-- ko if: name === "Text" -->
<input type="text">
<!-- /ko -->
<!-- ko ifnot: name === "Text" -->
<select data-bind='options: filterValues, optionsText: "name", value: "name"'> </select>
<!-- /ko -->
<td>
Updated fiddle that contains this code: http://jsfiddle.net/z22m1798/
I have a table which I fill with some numbers. There is a button in each row. After clicking this button I would like to decrement a counter in this row. How to to this with knockout?
<div class="panel panel-default">
<div class=panel-heading>Title</div>
<table class=table>
<thead>
<tr>
<th>Counter</th>
<th>Increment</th>
</tr>
</thead>
<tbody data-bind="foreach: records">
<tr>
<td data-bind="text: counter"></td>
<td> <input type="button" value="increment" data-bind=??? ></td>
</tr>
</tbody>
</table>
</div>
<script>
function AppViewModel() {
var self = this;
self.records = ko.observableArray([]);
$.getJSON("/data", function(data) {
self.records(data);
})
//function to decrement
}
ko.applyBindings(new AppViewModel());
</script>
I would do it this way:
Process data you get from server, turn counter property into observable and add function to decrement counter property
Restructure you code a little so viewmodel will be created by the time of ajax request
Move applyBindings call to ajax callback so it would fire when everything has been loaded
So the code would look like:
<tr>
<td data-bind="text: counter"></td>
<td> <input type="button" value="decrement" data-bind="click: decrement"></td>
</tr>
function AppViewModel() {
var self = this;
self.records = ko.observableArray([]);
}
var vm = new AppViewModel();
// load data from server
$.getJSON("/data", function(data) {
data.forEach( function(item) {
// make counter observable
item.counter = ko.observable(item.counter);
// add function to decrement
item.decrement = function() {
this.counter( this.counter()-1 );
}
})
// load array into viewmodel
vm.records(data);
// apply bindings when all obervables have been declared
ko.applyBindings(vm);
})
Check demo: Fiddle
I prefer to initialize and bind my viewmodel right away, but agree with the other poster that you need an observable.
Here is a solution that continues to create and bind your viewmodel right away, as in your original example, but instead of an array of the raw records you receive back it converts them into their own little model objects that have an observable for the counter and an increment function that can be data bound too. This decouples your data load from the life of the viewmodel, so if you wanted to add a button to load fresh data to overwrite it or anything like that, it's just another call to getData().
<!-- ... -->
<tbody data-bind="foreach: records">
<tr>
<td data-bind="text: counter"></td>
<td> <input type="button" value="increment" data-bind="click: increment" ></td>
</tr>
</tbody>
<!-- ... -->
<script>
function AppViewModel() {
var self = this;
self.records = ko.observableArray([]);
self.getData = function(){ /* ... */ };
self.getFakeData = function(){
var data = [{ counter: 1 }, { counter: 2}, { counter: 3 }];
var freshData = data.map(function(record){
return new AppRecord(record);
});
self.records(freshData);
};
}
function AppRecord(rawRecord) {
var self = this;
self.counter = ko.observable(rawRecord.counter);
self.increment = function(){
self.counter(self.counter() + 1);
};
}
var vm = new AppViewModel();
vm.getFakeData(); // replace with getData()
ko.applyBindings(vm);
</script>
Fiddle, with a getFakeData with sample data: https://jsfiddle.net/4hxyarLa/1/
If you are going to have a lot of rows and are concerned abut memory, you could put the increment function in a prototype method for the AppRecord and access the record via a parameter on the function, or you could add the function to the AppViewModel and bind to $parent.increment to call it and access the record via parameter passed to that function to increment it's counter property.
I'm in the process of replacing one hell of a lot of javascript/jquery code with knockoutjs and I'm trying to figure out the best way forward. I have no time to replace everything at the same time so I will have to integrate the knockout logic with the existing javascript...
Is there a way to populate a knockout view model from javascript which is not called from a data-bind attribute? Any help would be nice since I've not been able to find this anywhere else (at least not anything that worked).
I know what I'm mentioning here isn't the "correct" way of doing things, but I'm trying to migrate parts of the javascript code... Doing it all in one go isn't an option at the moment.
(using knockout 3.2)
Edit:
Typically the existing javascript does something like:
$('#productlist').append(productItemHtmlCode);
And I would rather have it do something like:
ViewModel.productList.push(productItemObject);
If I understand correctly, currently you have something like this:
<div id='myDiv'>
current status is: <span id='statusSpan'>Active</span>
</div>
with some corresponding javascript that might be something like:
function toggleStatus() {
var s= document.getElementById('statusSpan');
s.innerHTML = s.innerHTML == 'Active' ? 'Inactive' : 'Active';
}
And you want to change it so that the javascript is updating the viewmodel rather than manipulating the DOM?
var app = (function() {
var vm = {
statusText: ko.observable('Active'),
toggleStatus: toggleStatus
}
return vm
function toggleStatus() {
vm.statusText = vm.statusText == 'Active' ? 'Inactive' : 'Active';
}
}) ();
ko.applyBindings(app,document.getElementById('myDiv'));
And then the html would be
<div id='myDiv'>
current status is: <span id='statusSpan' data-bind="text: statusText"></span>
</div>
If that's what you're talking about, that's what Knockout is designed for. The javascript updates the viewmodel, knockout manipulates the DOM.
The example you give is easy to represent in Knockout.
the HTML:
<div>
<table data-bind="foreach: products">
<tr>
<td data-bind="text: id"></td>
<td data-bind="text: name"></td>
<td data-bind="text: category"></td>
</tr>
</table>
</div>
and in the viewmodel:
vm = {
products: ko.observableArray(), // empty array to start
addProduct: addProduct
}
return vm;
function addProduct(id, name, category) {
products.push({id: id, name: name, category:category});
}
etc.
I am new to Knockout and I am building a Simple POC for using knockout to build SPA(Single Page Application).
What I want to do is to show "Business Units" when the app loads and on selection of a business unit show all "Front End Units" under that business unit and on selection of a front end unit, show all "Sales Segments" under that front end unit.
All this will happen in a single page using the same view and the viewmodel will bind the model based on selected business unit or front end unit.
The issue I am facing is that, I have 5 business units that get bound properly first on document ready, but on selection of business unit, the front end units get repeated 5 times each. In this case, I have 2 front end units and each is shown 5 times. Same issue on selection of front end unit.
You can see this issue mimicked in the following jsFiddle sample - jsFiddle Link
Let me know if you can't access the jsfiddle link. In this sample, I have used arrays, but in actual I will be getting the data through async call to the oData service.
This is the view HTML:
<div id="divbu">
<h4 data-bind="text: Heading"></h4>
<ul data-role="listview" data-inset="true" data-bind="foreach: Collection">
<li data-role="list-divider" data-bind="text: EntityName"></li>
<li>
<a href="#" data-bind="click: $root.fnNextLevel">
<table border="0">
<tr>
<td>
<label style="font-size: 12px;">Bus. Plan: </label>
</td>
<td>
<label style="font-size: 12px;" data-bind="text: BusinessPlan"></label>
</td>
<td>
<label style="font-size: 12px;">Forecast: </label>
</td>
<td>
<label style="font-size: 12px;" data-bind="text: Forecast"></label>
</td>
</tr>
<tr>
<td>
<label style="font-size: 12px;">Gross Sales: </label>
</td>
<td colspan="3">
<label style="font-size: 12px;" data-bind="text: GrossSales"></label>
</td>
</tr>
</table>
</a>
</li>
</ul>
</div>
This is the model and view model:
function CommonModel(model, viewType) {
var self = this;
if (viewType == 'BU') {
self.EntityName = model[0];
self.BusinessUnit = model[0];
self.BusinessPlan = model[1];
self.Forecast = model[2];
self.GrossSales = model[3];
} else if (viewType == 'FEU') {
self.EntityName = model[1];
self.BusinessUnit = model[0];
self.FrontEndUnit = model[1];
self.BusinessPlan = model[2];
self.Forecast = model[3];
self.GrossSales = model[4];
} else if (viewType == 'SS') {
self.EntityName = model[2];
self.BusinessPlan = model[3];
self.Forecast = model[4];
self.GrossSales = model[5];
}
}
function ShipmentReportsViewModel(results, viewType) {
var self = this;
self.Collection = ko.observableArray([]);
for (var i = 0; i < results.length; i++) {
self.Collection.push(new CommonModel(results[i], viewType));
}
if (viewType == 'BU') {
self.Heading = "Business Units";
self.fnNextLevel = function (businessUnit) {
FetchFrontEndUnits(businessUnit);
};
self.Home = function () {
FetchBusinessUnits();
};
} else if (viewType == 'FEU') {
self.Heading = results[0][0];
self.fnNextLevel = function (frontEndUnit) {
FetchSalesSegments(frontEndUnit);
};
self.Home = function () {
FetchBusinessUnits();
};
} else if (viewType == 'SS') {
self.fnNextLevel = function () {
alert('No activity zone');
};
self.Heading = results[0][0] + ' - ' + results[0][1];
self.Home = function () {
FetchBusinessUnits();
};
}
}
You can see the complete code in the jsFiddle link.
I have also tried this with multiple views and multiple view models, where I apply bindings by giving the element ID. In this case, one flow from business unit -> sales segment is fine, but when I click on home or back button and I do binding again to that element, I face the same issue. (home and back button features are not done in jsFiddle example).
Let me know if more details are required. I did look into lot of other links in stack overflow, but nothing addressing this particular problem.
Any help is deeply appreciated. Thanks in advance.
The problem here is that you call your ko.applybindings TWICE and there is a foreach binding that iterate within 5 items, therefore the data are duplicated five times.
you should not call a ko.applybindings more than once on the same model.
Your model is always the same even if it's parametrized.
I had the same problem here: Data coming from an ObservableArray are displayed twice in my table
the fact that you have you business logic inside your viewModel is something that could be discussed, and it makes it not easy to fix this.
Make 3 classes, put them in a common model without logic inside. Then once you have applyed the ko.applyBindings once, you just have to modify the array like this:
viewModel.myArray(newValues)
Here is the fiddle with the amended code: http://jsfiddle.net/MaurizioPiccini/5B9Fd/17/
it does not do exaclty what you need but if remove the multiple bindings by moving the Collection object scope outside of your model.
As you can see the problem IS that you are calling the ko.applybindings twice on the same model.
Finally, I got this working. Thanks to #MaurizioIndenmark.
Though I have removed multiple call for ko.applybindings, I was still calling the view model multiple times. This was causing the issue.
Now, I have cleaner view model and I have different function calls for different actions and modify all the data required to be modified within these functions(events). Now, everything is working as expected.
This is how the view model looks now -
function ShipmentReportsViewModel(results) {
var self = this;
self.Heading = ko.observable();
self.BusinessUnits = ko.observableArray();
self.FrontEndUnits = ko.observableArray();
self.SalesSegments = ko.observableArray();
self.Home = function () {
var bu = FetchBusinessUnits();
self.Heading("Business Units");
self.BusinessUnits(bu);
self.FrontEndUnits(null);
self.SalesSegments(null);
};
self.fnFeu = function (businessUnit) {
var feu = FetchFrontEndUnits(businessUnit);
self.Heading(feu[0].BusinessUnit);
self.FrontEndUnits(feu);
self.BusinessUnits(null);
self.SalesSegments(null);
};
self.fnSalesSeg = function (frontEndUnit) {
var ss = FetchSalesSegments(frontEndUnit);
self.Heading(ss[0].BusinessUnit + ' - ' + ss[0].FrontEndUnit);
self.SalesSegments(ss);
self.BusinessUnits(null);
self.FrontEndUnits(null);
};
self.Home();
}
To see the entire working solution, please refer this jsFiddle
Thanks for all the valuable suggestions in getting this work.
I'm using Knockoutjs for the first time and I'm having trouble debugging because of my inability to log variables in console. I can see that my JS is loading properly in console, when I enter:
Home.TwitterFeedComponent I see an object returned. How do I use console.log in conjunction with knockout and subscribe?
var Home = Home || {};
var inheriting = inheriting || {};
Home.TwitterFeedComponent = function(attributes) {
if (arguments[0] === inheriting)
return;
Home.OnScreenComponent.call(this, attributes);
var component = this;
var recent_tweets = ko.observableArray();
var url = 'https://twitter.com/search.json?callback=?';
this.attributes.twitter_user_handle.subscribe(function(value) {
var twitter_parameters = {
include_entities: true,
include_rts: true,
from: value,
q: value,
count: '3'
}
result = function getTweets(){
$.getJSON(url,twitter_parameters,
function(json) {
console.log(json)
});
}
console.log(twitter_parameters);
});
};
Home.TwitterFeedComponent.prototype = new Home.OnScreenComponent(inheriting);
Home.TwitterFeedComponent.prototype.constructor = Home.TwitterFeedComponent;
I don't see the problem in your code, but if you want to log 'Observables', you have to log it as follows:
console.log(observableVar());
I'm a little unclear as to the exact scope of the question -- however, if like mine, this question is directed toward the use of console.log within your HTML.
Here is a little set of code that may help:
<div class="tab-content" data-bind="with: ClientSearch.selectedClient">
...
<table class="table table-striped table-condensed table-hover">
<thead></thead>
<tbody>
<!-- ko foreach: { data: _general, as: 'item' } -->
<tr>
<td data-bind="text: eval( 'console.log(\' le item \', item)' )"></td>
</tr>
<!-- /ko -->
</tbody>
</table>
...
</div>
This code simply logs an item inside of a foreach to the console.
Hope this helps!