Get selected text on dropdown change event in Knockout.js - javascript

I am trying to get the text of selected index in dropdown using knockout.js,
following is my HTML
<select name="" id="management" class="form-control" data-bind="value: ManagementCompanies,optionText:ManagementCompaniestxt">
<option value="0">---Select---</option>
<option value="1">abcd</option>
<option value="2">efgh</option>
</select>
following is my Model binding:
var FilterViewModel = {
ManagementCompanies: ko.observable(''),
ManagementCompaniestxt:ko.observable('')
}
FilterViewModel.ManagementCompanies.subscribe(function (newValue) {
alert(FilterViewModel.ManagementCompaniestxt());
});
ko.applyBindings(FilterViewModel, window.document.getElementById("SelectFilters"));
i have tried to bind using Text as well but didn't work.
how can i get selected text abcd in subscribe event?
thanks

It's a bit weird that you're trying to get data from your view to your viewmodel. Usually, your view is a representation of your viewmodel. It's better to have the data needed to render your <select> in your model, and use knockout's options data-bind to render it.
Here's how you can do this:
var FilterViewModel = {
ManagementCompanies: ko.observable(''),
ManagementCompaniestxt: ko.observable(''),
options: [
{ text: "---Select---", value: 0 },
{ text: "abcd", value: 1 },
{ text: "efgh", value: 2 }]
}
FilterViewModel.ManagementCompanies.subscribe(function(newValue) {
console.log(newValue.text);
});
ko.applyBindings(FilterViewModel);
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script>
<select data-bind="value: ManagementCompanies,
options:options,
optionsText: 'text'">
</select>

Related

How to preselect a specific element from dropdown using ng-repeat

This is my html code:
<select id="selectFileType" ng-model="instance.fileType" required>
<option ng-repeat="(key, value) in fileTypes" id="key" value="{{key}}">{{key}} ({{value}})</option>
</select>
I am using a map of items to fill the list with information - now I want to pre-select a specific element based on the key but all the solutions I found didn`t work.
E.g. I tried to use the id field to use something like:
document.getElementById("A").selected = true;
Does someone have an idea what I should do?
Thanks and have a nice day
Use the ng-selected directive to set your pre-selected option.
angular.module('myApp', [])
.controller('ctrl', function($scope) {
$scope.vm = {
priceTypes: [{
id: 3,
name: 'pound'
},
{
id: 5,
name: 'Yen'
},
{
id: 6,
name: 'dollar'
}
]
};
//select model value
$scope.localModel = {
priceType: $scope.vm.priceTypes[1]
};
})
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.0/angular.min.js"></script>
<div ng-app="myApp" ng-controller="ctrl">
<select ng-model="localModel.priceType">
<option
ng-repeat="item in vm.priceTypes as item"
ng-selected="localModel.priceType.id == item.id"
value="{{item}}"
>{{item.name}}</option>
</select>
<div>
priceType: {{ localModel.priceType }}
</div>
</div>

on Change event in select with knockout

I have a problem how to call onchanges knock js to my select option, i already have a function and html, but when i choose the select option, nothing changes
<select data-bind="event:{change:setSelectedStation() },
options: seedData,
optionsText: 'text',
optionsValue: 'value'">
</select>
here is my function
setSelectedStation: function(element, KioskId){
this.getPopUp().closeModal();
$('.selected-station').html(element);
$('[name="popstation_detail"]').val(element);
$('[name="popstation_address"]').val(KioskId);
$('[name="popstation_text"]').val(element);
// console.log($('[name="popstation_text"]').val());
this.isSelectedStationVisible(true);
},
Use knockout's two-way data-binds instead of manually subscribing to UI events.
Knockout's value data-bind listens to UI changes and automatically keeps track of the latest value for you.
Instead of replacing HTML via jQuery methods, you use text, attr and other value bindings to update the UI whenever your selection changes.
If you want to perform additional work when a selection changes (e.g. closing a pop up), you subscribe to the selected value.
var VM = function() {
this.seedData = [
{
text: "Item 1",
data: "Some other stuff"
},
{
text: "Item 2",
data: "Something else"
},
{
text: "Item 3",
data: "Another thing"
}
];
this.selectedItem = ko.observable();
this.selectedItem.subscribe(function(latest) {
console.log("Input changed");
}, this);
};
ko.applyBindings(new VM());
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-min.js"></script>
<select data-bind="
value: selectedItem,
options: seedData,
optionsText: 'text'">
</select>
<!-- ko with: selectedItem -->
<p>
Your selection: <span data-bind="text: data"></span>
</p>
<!-- /ko -->

Vue.js dependent select

I'm in very beginning stage learning Vue.js and encountered problem I can't figure out right now. So I have 1 select field:
data: {
list: {
'Option 1': [ { size:'1',prize:'5' }, { size:'2',prize:'10' } ]
}
}
Then I populating first select field like this:
<select v-model="firstOptions" v-on:change="onChange">
<option v-for="(item, index) in list">{{ index }}</option>
</select>
At this point everything is fine, but how to populate another select field based on first select? I need to access size and price.
I'm think this should be done here:
methods: {
onChange: function() {
// get options for second select field
}
}
I'm assuming here in your data structure, list, that the value of each property defines the options you will use in the second select. The key here is the model for the first select drives the options for the second.
<option v-for="option in list[firstOption]" value="option.size">{{option.prize}}</option>
I'm not sure how exactly you want your text and values laid out in the first or second selects, but here is an example.
new Vue({
el:"#app",
data: {
firstOption: null,
secondOption: null,
list: {
'Option 1': [ { size:'1',prize:'5' }, { size:'2',prize:'10' } ],
'Option 2': [{size:'3', prize:'8'}]
}
}
})
and in your template
<div id="app">
<select v-model="firstOption">
<option v-for="(item, index) in list">{{ index }}</option>
</select>
<select v-model="secondOption" v-if="firstOption">
<option v-for="option in list[firstOption]" value="option.size">{{option.prize}}</option>
</select>
</div>
Example in codepen.

Angular 2.0 and TypeScript - Populate <select> options from multi-dimensional array objects

I would like to populate the <select name="selectmodel"> <option> from a nested array of objects based on the selection of the <select name="selectmake"> <option> element.
Here is the multi-dimensional array:
muscleCars = [
{
id: 1, name: "Chevrolet", models: [
{ model: "Camaro" },
{ model: "Corvette" }
]
},
{
id: 2, name: "Dodge", models: [
{ model: "Charger" },
{ model: "Challenger" },
{ model: "Viper" }
]
},
{
id: 3, name: "Ford", models: [
{ model: "GT" },
{ model: "Mustang" }
]
}
];
This is the HTML
//select for Make:
<select name="selectmake" [(ngModel)]="makeListFilter">
<option *ngFor="let muscleCar of muscleCars" [ngValue]="muscleCar.name">{{muscleCar.name}}</option>
</select>
//select for Model:
<select name="selectmodel" [(ngModel)]="modelListFilter">
<option *ngFor="let muscleCar of muscleCars" [ngValue]="muscleCar.models">{{muscleCar.models}}</option>
</select>
So, basically when you select Chevrolet for example, I would like to have the second element populated with Camaro and Corvette.
Currently, the second select element is populated with an array [object Object] for each make, but can't figure out how to dig this deeper.
Here is a plunk:
https://embed.plnkr.co/0eEIJg5uzL6KsI70wWsC/
Any help would be appreciated.
This is how your HTML should look like:
<select name="selectmake" [(ngModel)]="makeListFilter">
<option *ngFor="let muscleCar of muscleCars" [ngValue]="muscleCar">{{muscleCar.name}}</option>
</select>
<select name="selectmodel" [(ngModel)]="modelListFilter">
<option *ngFor="let carModel of makeListFilter?.models" [ngValue]="carModel.model">{{carModel.model}}</option>
</select>
So, what's happening here is that selected value of selectmake dropdown is binded to makeListFilter and second dropdown selectmodel is populated based on selected value of first dropdown. You will notice I binded the whole Object that is selected in first dropdown using ngValue directive so it can be used to populate second dropdown. Another interesting thing you'll notice is Elvis operator (?) I used in second dropdown - it is used to tell second dropdown to populate itself only after value is selected in first dropdown, this is necessary to avoid getting error for iterating through an undefined value. If you don't want to use Elvis operator, you can use *ngIf directive to prevent getting mentioned error, but that means that second dropdown will appear only after you select something in the first dropdown:
<select *ngIf="makeListFilter" name="selectmodel" [(ngModel)]="modelListFilter">
<option *ngFor="let carModel of makeListFilter.models" [ngValue]="carModel.model">{{carModel.model}}</option>
</select>

How to have a default option in Angular.js select box

I have searched Google and can't find anything on this.
I have this code.
<select ng-model="somethingHere"
ng-options="option.value as option.name for option in options"
></select>
With some data like this
options = [{
name: 'Something Cool',
value: 'something-cool-value'
}, {
name: 'Something Else',
value: 'something-else-value'
}];
And the output is something like this.
<select ng-model="somethingHere"
ng-options="option.value as option.name for option in options"
class="ng-pristine ng-valid">
<option value="?" selected="selected"></option>
<option value="0">Something Cool</option>
<option value="1">Something Else</option>
</select>
How is it possible to set the first option in the data as the default value so you would get a result like this.
<select ng-model="somethingHere" ....>
<option value="0" selected="selected">Something Cool</option>
<option value="1">Something Else</option>
</select>
You can simply use ng-init like this
<select ng-init="somethingHere = options[0]"
ng-model="somethingHere"
ng-options="option.name for option in options">
</select>
If you want to make sure your $scope.somethingHere value doesn't get overwritten when your view initializes, you'll want to coalesce (somethingHere = somethingHere || options[0].value) the value in your ng-init like so:
<select ng-model="somethingHere"
ng-init="somethingHere = somethingHere || options[0].value"
ng-options="option.value as option.name for option in options">
</select>
Try this:
HTML
<select
ng-model="selectedOption"
ng-options="option.name for option in options">
</select>
Javascript
function Ctrl($scope) {
$scope.options = [
{
name: 'Something Cool',
value: 'something-cool-value'
},
{
name: 'Something Else',
value: 'something-else-value'
}
];
$scope.selectedOption = $scope.options[0];
}
Plunker here.
If you really want to set the value that will be bound to the model, then change the ng-options attribute to
ng-options="option.value as option.name for option in options"
and the Javascript to
...
$scope.selectedOption = $scope.options[0].value;
Another Plunker here considering the above.
Only one answer by Srivathsa Harish Venkataramana mentioned track by which is indeed a solution for this!
Here is an example along with Plunker (link below) of how to use track by in select ng-options:
<select ng-model="selectedCity"
ng-options="city as city.name for city in cities track by city.id">
<option value="">-- Select City --</option>
</select>
If selectedCity is defined on angular scope, and it has id property with the same value as any id of any city on the cities list, it'll be auto selected on load.
Here is Plunker for this:
http://plnkr.co/edit/1EVs7R20pCffewrG0EmI?p=preview
See source documentation for more details:
https://code.angularjs.org/1.3.15/docs/api/ng/directive/select
I think, after the inclusion of 'track by', you can use it in ng-options to get what you wanted, like the following
<select ng-model="somethingHere" ng-options="option.name for option in options track by option.value" ></select>
This way of doing it is better because when you want to replace the list of strings with list of objects you will just change this to
<select ng-model="somethingHere" ng-options="object.name for option in options track by object.id" ></select>
where somethingHere is an object with the properties name and id, of course. Please note, 'as' is not used in this way of expressing the ng-options, because it will only set the value and you will not be able to change it when you are using track by
The accepted answer use ng-init, but document says to avoid ng-init if possible.
The only appropriate use of ngInit is for aliasing special properties
of ngRepeat, as seen in the demo below. Besides this case, you should
use controllers rather than ngInit to initialize values on a scope.
You also can use ng-repeat instead of ng-options for your options. With ng-repeat, you can use ng-selected with ng-repeat special properties. i.e. $index, $odd, $even to make this work without any coding.
$first is one of the ng-repeat special properties.
<select ng-model="foo">
<option ng-selected="$first" ng-repeat="(id,value) in myOptions" value="{{id}}">
{{value}}
</option>
</select>
---------------------- EDIT ----------------
Although this works, I would prefer #mik-t's answer when you know what value to select, https://stackoverflow.com/a/29564802/454252, which uses track-by and ng-options without using ng-init or ng-repeat.
This answer should only be used when you must select the first item without knowing what value to choose. e.g., I am using this for auto completion which requires to choose the FIRST item all the time.
My solution to this was use html to hardcode my default option. Like so:
In HAML:
%select{'ng-model' => 'province', 'ng-options' => "province as province for province in summary.provinces", 'chosen' => "chosen-select", 'data-placeholder' => "BC & ON"}
%option{:value => "", :selected => "selected"}
BC & ON
In HTML:
<select ng-model="province" ng-options="province as province for province in summary.provinces" chosen="chosen-select" data-placeholder="BC & ON">
<option value="" selected="selected">BC & ON</option>
</select>
I want my default option to return all values from my api, that's why I have a blank value. Also excuse my haml. I know this isn't directly an answer to the OP's question, but people find this on Google. Hope this helps someone else.
Use below code to populate selected option from your model.
<select id="roomForListing" ng-model="selectedRoom.roomName" >
<option ng-repeat="room in roomList" title="{{room.roomName}}" ng-selected="{{room.roomName == selectedRoom.roomName}}" value="{{room.roomName}}">{{room.roomName}}</option>
</select>
Depending on how many options you have, you could put your values in an array and auto-populate your options like this
<select ng-model="somethingHere.values" ng-options="values for values in [5,4,3,2,1]">
<option value="">Pick a Number</option>
</select>
In my case, I was need to insert a initial value only to tell to user to select an option, so, I do like the code below:
<select ...
<option value="" ng-selected="selected">Select one option</option>
</select>
When I tryed an option with the value != of an empty string (null) the option was substituted by angular, but, when put an option like that (with null value), the select apear with this option.
Sorry by my bad english and I hope that I help in something with this.
Using select with ngOptions and setting a default value:
See the ngOptions documentation for more ngOptions usage examples.
angular.module('defaultValueSelect', [])
.controller('ExampleController', ['$scope', function($scope) {
$scope.data = {
availableOptions: [
{id: '1', name: 'Option A'},
{id: '2', name: 'Option B'},
{id: '3', name: 'Option C'}
],
selectedOption: {id: '2', name: 'Option B'} //This sets the default value of the select in the ui
};
}]);
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.0-rc.0/angular.min.js"></script>
<body ng-app="defaultValueSelect">
<div ng-controller="ExampleController">
<form name="myForm">
<label for="mySelect">Make a choice:</label>
<select name="mySelect" id="mySelect"
ng-options="option.name for option in data.availableOptions track by option.id"
ng-model="data.selectedOption"></select>
</form>
<hr>
<tt>option = {{data.selectedOption}}</tt><br/>
</div>
plnkr.co
Official documentation about HTML SELECT element with angular data-binding.
Binding select to a non-string value via ngModel parsing / formatting:
(function(angular) {
'use strict';
angular.module('nonStringSelect', [])
.run(function($rootScope) {
$rootScope.model = { id: 2 };
})
.directive('convertToNumber', function() {
return {
require: 'ngModel',
link: function(scope, element, attrs, ngModel) {
ngModel.$parsers.push(function(val) {
return parseInt(val, 10);
});
ngModel.$formatters.push(function(val) {
return '' + val;
});
}
};
});
})(window.angular);
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.0-rc.1/angular.min.js"></script>
<body ng-app="nonStringSelect">
<select ng-model="model.id" convert-to-number>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>
{{ model }}
</body>
plnkr.co
Other example:
angular.module('defaultValueSelect', [])
.controller('ExampleController', ['$scope', function($scope) {
$scope.availableOptions = [
{ name: 'Apple', value: 'apple' },
{ name: 'Banana', value: 'banana' },
{ name: 'Kiwi', value: 'kiwi' }
];
$scope.data = {selectedOption : $scope.availableOptions[1].value};
}]);
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.0-rc.0/angular.min.js"></script>
<body ng-app="defaultValueSelect">
<div ng-controller="ExampleController">
<form name="myForm">
<select ng-model="data.selectedOption" required ng-options="option.value as option.name for option in availableOptions"></select>
</form>
</div>
</body>
jsfiddle
This worked for me.
<select ng-model="somethingHere" ng-init="somethingHere='Cool'">
<option value="Cool">Something Cool</option>
<option value="Else">Something Else</option>
</select>
In response to Ben Lesh's answer, there should be this line
ng-init="somethingHere = somethingHere || options[0]"
instead of
ng-init="somethingHere = somethingHere || options[0].value"
That is,
<select ng-model="somethingHere"
ng-init="somethingHere = somethingHere || options[0]"
ng-options="option.name for option in options track by option.value">
</select>
In my case since the default varies from case to case in the form.
I add a custom attribute in the select tag.
<select setSeletected="{{data.value}}">
<option value="value1"> value1....
<option value="value2"> value2....
......
in the directives I created a script that checks the value and when angular fills it in sets the option with that value to selected.
.directive('setSelected', function(){
restrict: 'A',
link: (scope, element, attrs){
function setSel=(){
//test if the value is defined if not try again if so run the command
if (typeof attrs.setSelected=='undefined'){
window.setTimeout( function(){setSel()},300)
}else{
element.find('[value="'+attrs.setSelected+'"]').prop('selected',true);
}
}
}
setSel()
})
just translated this from coffescript on the fly at least the jist of it is correct if not the hole thing.
It's not the simplest way but get it done when the value varies
Simply use ng-selected="true" as follows:
<select ng-model="myModel">
<option value="a" ng-selected="true">A</option>
<option value="b">B</option>
</select>
This working for me
ng-selected="true"
I would set the model in the controller. Then the select will default to that value. Ex:
html:
<select ng-options="..." ng-model="selectedItem">
Angular controller (using resource):
myResource.items(function(items){
$scope.items=items;
if(items.length>0){
$scope.selectedItem= items[0];
//if you want the first. Could be from config whatever
}
});
If you are using ng-options to render you drop down than option having same value as of ng-modal is default selected.
Consider the example:
<select ng-options="list.key as list.name for list in lists track by list.id" ng-model="selectedItem">
So option having same value of list.key and selectedItem, is default selected.
I needed the default “Please Select” to be unselectable. I also needed to be able to conditionally set a default selected option.
I achieved this the following simplistic way:
JS code:
// Flip these 2 to test selected default or no default with default “Please Select” text
//$scope.defaultOption = 0;
$scope.defaultOption = { key: '3', value: 'Option 3' };
$scope.options = [
{ key: '1', value: 'Option 1' },
{ key: '2', value: 'Option 2' },
{ key: '3', value: 'Option 3' },
{ key: '4', value: 'Option 4' }
];
getOptions();
function getOptions(){
if ($scope.defaultOption != 0)
{ $scope.options.selectedOption = $scope.defaultOption; }
}
HTML:
<select name="OptionSelect" id="OptionSelect" ng-model="options.selectedOption" ng-options="item.value for item in options track by item.key">
<option value="" disabled selected style="display: none;"> -- Please Select -- </option>
</select>
<h1>You selected: {{options.selectedOption.key}}</h1>
I hope this helps someone else that has similar requirements.
The "Please Select" was accomplished through Joffrey Outtier's answer here.
If you have some thing instead of just init the date part, you can use ng-init() by declare it in your controller, and use it in the top of your HTML.
This function will work like a constructor for your controller, and you can initiate your variables there.
angular.module('myApp', [])
.controller('myController', ['$scope', ($scope) => {
$scope.allOptions = [
{ name: 'Apple', value: 'apple' },
{ name: 'Banana', value: 'banana' }
];
$scope.myInit = () => {
$scope.userSelected = 'apple'
// Other initiations can goes here..
}
}]);
<body ng-app="myApp">
<div ng-controller="myController" ng-init="init()">
<select ng-model="userSelected" ng-options="option.value as option.name for option in allOptions"></select>
</div>
</body>
<!--
Using following solution you can set initial
default value at controller as well as after change option selected value shown as default.
-->
<script type="text/javascript">
function myCtrl($scope)
{
//...
$scope.myModel=Initial Default Value; //set default value as required
//..
}
</script>
<select ng-model="myModel"
ng-init="myModel= myModel"
ng-options="option.value as option.name for option in options">
</select>
try this in your angular controller...
$somethingHere = {name: 'Something Cool'};
You can set a value, but you are using a complex type and the angular will search key/value to set in your view.
And, if does not work, try this :
ng-options="option.value as option.name for option in options track by option.name"
I think the easiest way is
ng-selected="$first"

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