Cannot set the default option in select in angular2 - angular2-forms

I am trying to select a default option in select. Below is my code
<select [id]="index" class="form-control" (change)="onChange($event.target.selectedIndex,$event.target.value)" (focus)="onFocus($event.target.selectedIndex)">
<option value="" [selected]="true" disabled="true">{{'rec.select' | translate}}</option>
<option *ngFor="let attributeType of attributeTypeValues" [disabled]="attributeType.disabled" [value]="attributeType.attrTypeNm"
[selected]="attributeType.attrTypeNm===attributeEditForm.controls['attrType'].value">
{{attributeType.attrTypeDesc}}
</option>
</select>
I can see ng-reflect-selected as true. Yet nothing gets selected in UI.
The code works fine on first time load. But as the selection changes the changes are not reflected in UI. For example, if the form value is changed, then the selection condition changes and the same selected option does not get reflected in ui.

I personally would use a [(ngModel)] approach in this situation:
<select [(ngModel)]="selectedValue">
<option *ngFor="let v of values" [ngValue]="v">{{v.name}}</option>
</select>
with the following in the controller:
values = [
{ id: 0, name: "Value0" },
{ id: 1, name: "Value1" },
{ id: 2, name: "Value2" },
{ id: 3, name: "Value3" },
];
selectedValue = this.values[0];
important is that the default selection needs to be the correct object instance than the one used in the value list. Another object instance even with the same properties and values won't do => object identity is checked.

The easy way and fastest way would be to check if your *ngFor fresh new variable is equal to your logic in the [selected] : (example)
<select (change)="size($event.target.value)" class="size-option" name="size">
<option *ngFor="let number of [14, 16, 18, 20, 22]" value="{{number}}" [selected]="number == 16">{{number}}</option>
</select>

Related

How to retrieve data attribute from select options of a form select menu using stimulus? [duplicate]

How do I get the selected value from a dropdown list using JavaScript?
<form>
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2" selected="selected">test2</option>
<option value="3">test3</option>
</select>
</form>
Given a select element that looks like this:
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2" selected="selected">test2</option>
<option value="3">test3</option>
</select>
Running this code:
var e = document.getElementById("ddlViewBy");
var value = e.value;
var text = e.options[e.selectedIndex].text;
Results in:
value == 2
text == "test2"
Interactive example:
var e = document.getElementById("ddlViewBy");
function onChange() {
var value = e.value;
var text = e.options[e.selectedIndex].text;
console.log(value, text);
}
e.onchange = onChange;
onChange();
<form>
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2" selected="selected">test2</option>
<option value="3">test3</option>
</select>
</form>
Plain JavaScript:
var e = document.getElementById("elementId");
var value = e.options[e.selectedIndex].value;
var text = e.options[e.selectedIndex].text;
jQuery:
$("#elementId :selected").text(); // The text content of the selected option
$("#elementId").val(); // The value of the selected option
AngularJS: (http://jsfiddle.net/qk5wwyct):
// HTML
<select ng-model="selectItem" ng-options="item as item.text for item in items">
</select>
<p>Text: {{selectItem.text}}</p>
<p>Value: {{selectItem.value}}</p>
// JavaScript
$scope.items = [{
value: 'item_1_id',
text: 'Item 1'
}, {
value: 'item_2_id',
text: 'Item 2'
}];
var strUser = e.options[e.selectedIndex].value;
This is correct and should give you the value.
Is it the text you're after?
var strUser = e.options[e.selectedIndex].text;
So you're clear on the terminology:
<select>
<option value="hello">Hello World</option>
</select>
This option has:
Index = 0
Value = hello
Text = Hello World
The following code exhibits various examples related to getting/putting of values from input/select fields using JavaScript.
Source Link
Working Javascript & jQuery Demo
<select id="Ultra" onchange="run()"> <!--Call run() function-->
<option value="0">Select</option>
<option value="8">text1</option>
<option value="5">text2</option>
<option value="4">text3</option>
</select><br><br>
TextBox1<br>
<input type="text" id="srt" placeholder="get value on option select"><br>
TextBox2<br>
<input type="text" id="rtt" placeholder="Write Something !" onkeyup="up()">
The following script is getting the value of the selected option and putting it in text box 1
<script>
function run() {
document.getElementById("srt").value = document.getElementById("Ultra").value;
}
</script>
The following script is getting a value from a text box 2 and alerting with its value
<script>
function up() {
//if (document.getElementById("srt").value != "") {
var dop = document.getElementById("srt").value;
//}
alert(dop);
}
</script>
The following script is calling a function from a function
<script>
function up() {
var dop = document.getElementById("srt").value;
pop(dop); // Calling function pop
}
function pop(val) {
alert(val);
}?
</script>
var selectedValue = document.getElementById("ddlViewBy").value;
If you ever run across code written purely for Internet Explorer you might see this:
var e = document.getElementById("ddlViewBy");
var strUser = e.options(e.selectedIndex).value;
Running the above in Firefox et al will give you an 'is not a function' error, because Internet Explorer allows you to get away with using () instead of []:
var e = document.getElementById("ddlViewBy");
var strUser = e.options[e.selectedIndex].value;
The correct way is to use square brackets.
Use:
<select id="Ultra" onchange="alert(this.value)">
<option value="0">Select</option>
<option value="8">text1</option>
<option value="5">text2</option>
<option value="4">text3</option>
</select>
Any input/form field can use a “this” keyword when you are accessing it from inside the element. This eliminates the need for locating a form in the DOM tree and then locating this element inside the form.
There are two ways to get this done either using JavaScript or jQuery.
JavaScript:
var getValue = document.getElementById('ddlViewBy').selectedOptions[0].value;
alert (getValue); // This will output the value selected.
OR
var ddlViewBy = document.getElementById('ddlViewBy');
var value = ddlViewBy.options[ddlViewBy.selectedIndex].value;
var text = ddlViewBy.options[ddlViewBy.selectedIndex].text;
alert (value); // This will output the value selected
alert (text); // This will output the text of the value selected
jQuery:
$("#ddlViewBy:selected").text(); // Text of the selected value
$("#ddlViewBy").val(); // Outputs the value of the ID in 'ddlViewBy'
Beginners are likely to want to access values from a select with the NAME attribute rather than ID attribute. We know all form elements need names, even before they get ids.
So, I'm adding the getElementsByName() solution just for new developers to see too.
NB. names for form elements will need to be unique for your form to be usable once posted, but the DOM can allow a name be shared by more than one element. For that reason consider adding IDs to forms if you can, or be explicit with form element names my_nth_select_named_x and my_nth_text_input_named_y.
Example using getElementsByName:
var e = document.getElementsByName("my_select_with_name_ddlViewBy")[0];
var strUser = e.options[e.selectedIndex].value;
Just use
$('#SelectBoxId option:selected').text(); for getting the text as listed
$('#SelectBoxId').val(); for getting the selected index value
I don't know if I'm the one that doesn't get the question right, but this just worked for me:
Use an onchange() event in your HTML, for example.
<select id="numberToSelect" onchange="selectNum()">
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>
JavaScript
function selectNum() {
var strUser = document.getElementById("numberToSelect").value;
}
This will give you whatever value is on the select dropdown per click.
Using jQuery:
$('select').val();
The previous answers still leave room for improvement because of the possibilities, the intuitiveness of the code, and the use of id versus name. One can get a read-out of three data of a selected option -- its index number, its value and its text. This simple, cross-browser code does all three:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Demo GetSelectOptionData</title>
</head>
<body>
<form name="demoForm">
<select name="demoSelect" onchange="showData()">
<option value="zilch">Select:</option>
<option value="A">Option 1</option>
<option value="B">Option 2</option>
<option value="C">Option 3</option>
</select>
</form>
<p id="firstP"> </p>
<p id="secondP"> </p>
<p id="thirdP"> </p>
<script>
function showData() {
var theSelect = demoForm.demoSelect;
var firstP = document.getElementById('firstP');
var secondP = document.getElementById('secondP');
var thirdP = document.getElementById('thirdP');
firstP.innerHTML = ('This option\'s index number is: ' + theSelect.selectedIndex + ' (Javascript index numbers start at 0)');
secondP.innerHTML = ('Its value is: ' + theSelect[theSelect.selectedIndex].value);
thirdP.innerHTML = ('Its text is: ' + theSelect[theSelect.selectedIndex].text);
}
</script>
</body>
</html>
Live demo: http://jsbin.com/jiwena/1/edit?html,output .
id should be used for make-up purposes. For functional form purposes, name is still valid, also in HTML5, and should still be used. Lastly, mind the use of square versus round brackets in certain places. As was explained before, only (older versions of) Internet Explorer will accept round ones in all places.
Another solution is:
document.getElementById('elementId').selectedOptions[0].value
The simplest way to do this is:
var value = document.getElementById("selectId").value;
You can use querySelector.
E.g.
var myElement = document.getElementById('ddlViewBy');
var myValue = myElement.querySelector('[selected]').value;
Running example of how it works:
var e = document.getElementById("ddlViewBy");
var val1 = e.options[e.selectedIndex].value;
var txt = e.options[e.selectedIndex].text;
document.write("<br />Selected option Value: "+ val1);
document.write("<br />Selected option Text: "+ txt);
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2">test2</option>
<option value="3" selected="selected">test3</option>
</select>
Note: The values don't change as the dropdown is changed, if you require that functionality then an onClick change is to be implemented.
To go along with the previous answers, this is how I do it as a one-liner. This is for getting the actual text of the selected option. There are good examples for getting the index number already. (And for the text, I just wanted to show this way)
let selText = document.getElementById('elementId').options[document.getElementById('elementId').selectedIndex].text
In some rare instances you may need to use parentheses, but this would be very rare.
let selText = (document.getElementById('elementId')).options[(document.getElementById('elementId')).selectedIndex].text;
I doubt this processes any faster than the two line version. I simply like to consolidate my code as much as possible.
Unfortunately this still fetches the element twice, which is not ideal. A method that only grabs the element once would be more useful, but I have not figured that out yet, in regards to doing this with one line of code.
I have a bit different view of how to achieve this. I'm usually doing this with the following approach (it is an easier way and works with every browser as far as I know):
<select onChange="functionToCall(this.value);" id="ddlViewBy">
<option value="value1">Text one</option>
<option value="value2">Text two</option>
<option value="value3">Text three</option>
<option value="valueN">Text N</option>
</select>
In 2015, in Firefox, the following also works.
e.options.selectedIndex
In more modern browsers, querySelector allows us to retrieve the selected option in one statement, using the :checked pseudo-class. From the selected option, we can gather whatever information we need:
const opt = document.querySelector('#ddlViewBy option:checked');
// opt is now the selected option, so
console.log(opt.value, 'is the selected value');
console.log(opt.text, "is the selected option's text");
<select id="ddlViewBy">
<option value="1">test1</option>
<option value="2" selected="selected">test2</option>
<option value="3">test3</option>
</select>
event.target.value inside the onChange callback did the trick for me.
Most answers here get the value of the "this" select menu onchange by a plain text JavaScript selector.
For example:
document.getElementById("ddlViewBy").value;
This is not a DRY approach.
DRY (three lines of code):
function handleChange(e) {
let innerText = e.target[e.target.options.selectedIndex].innerText;
let value = e.target.value;
/* Do something with these values */
}
Get the first select option:
console.log(e.target[0]); /* Output: <option value="value_hello">Hello innerText</option>*/
With this idea in mind, we dynamically return a "this" select option item (by selectedIndex):
e.target[e.target.options.selectedIndex].innerText;
Demo
let log = document.getElementById('log');
function handleChange(e) {
let innerText = e.target[e.target.options.selectedIndex].innerText;
let value = e.target.value;
log.innerHTML = `<table>
<tr><th>value</th><th>innerText</th></tr>
<tr><td>${value}</td><td>${innerText}</td></tr>
</table>`;
}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/milligram/1.4.1/milligram.css">
<select id="greet" onchange="handleChange(event)">
<option value="value_hello">Hello innerText</option>
<option value="value_goodbye">Goodbye innerText</option>
<option value="value_seeYou">See you... innerText</option>
</select>
<select id="other_select_menu" onchange="handleChange(event)">
<option value="value_paris">Paris innerText</option>
<option value="value_ny">New York innerText</option>
</select>
<div id="log"></div>
Here is a JavaScript code line:
var x = document.form1.list.value;
Assuming that the dropdown menu named list name="list" and included in a form with name attribute name="form1".
I think you can attach an event listener to the select tag itself e.g:
<script>
document.addEventListener("DOMContentLoaded", (_) => {
document.querySelector("select").addEventListener("change", (e) => {
console.log(e.target.value);
});
});
</script>
In this scenario, you should make sure you have a value attribute for all of your options, and they are not null.
You should be using querySelector to achieve this. This also standardizes the way of getting a value from form elements.
var dropDownValue = document.querySelector('#ddlViewBy').value;
Fiddle: https://jsfiddle.net/3t80pubr/
Try
ddlViewBy.value // value
ddlViewBy.selectedOptions[0].text // label
console.log( ddlViewBy.value );
console.log( ddlViewBy.selectedOptions[0].text );
<select id="ddlViewBy">
<option value="1">Happy</option>
<option value="2">Tree</option>
<option value="3" selected="selected">Friends</option>
</select>
Here's an easy way to do it in an onchange function:
event.target.options[event.target.selectedIndex].dataset.name
<select name="test" id="test" >
<option value="1" full-name="Apple">A</option>
<option value="2" full-name="Ball">B</option>
<option value="3" full-name="Cat" selected>C</option>
</select>
var obj = document.getElementById('test');
obj.options[obj.selectedIndex].value; //3
obj.options[obj.selectedIndex].text; //C
obj.options[obj.selectedIndex].getAttribute('full-name'); //Cat
obj.options[obj.selectedIndex].selected; //true
There is a workaround, using the EasyUI framework with all of its plugins.
You only need to add some EasyUI object that can read from an input as a "bridge" to the drop-down menu.
Example: easyui-searchbox
To the left, the drop-down, to the right, the easyui-searchbox:
...
<input id="ss" class="easyui-searchbox" style="width:300px"
data-options=" searcher:my_function,
prompt:'Enter value',
menu:'#mm'">
<div id="mm" style="width:200px">
<div data-options="name:'1'">test1</div>
<div data-options="name:'2'">test2</div>
</div>
...
...
<script type="text/javascript">
function my_js_function(triggeredByButton = false){
// normal text of the searchbox (what you entered)
var value = $("#ss").searchbox("getValue");
// what you chose from the drop-down menu
var name = $("#ss").searchbox("getName");
...
Mind: the var name is the '1' or '2', that is, the "value of the drop-down", while var value is the value that was entered in the easyui-searchbox instead and not relevant if you only want to know the value of the drop-down.
I checked how EasyUI fetches that #mm name, and I could not find out how to get that name without the help of EasyUI. The jQuery behind getName:
getName:function(jq){
return $.data(jq[0],"searchbox").searchbox.find("input.textbox-value").attr("name");
}
Mind that the return of this function is not the value of the easyui-searchbox, but the name of the #mm drop-down that was used as the menu parameter of the easyui-searchbox. Somehow EasyUI must get that other value, therefore it must be possible.
If you do not want any plugin to be seen, make it as tiny as possible? Or find perhaps a plugin that does not need a form at all in the link above, I just did not take the time.

emberjs: Passing selected value to select field in form

I am attempting to add a SELECT field from first principles using ember and am having difficulty working out how to pass the currently selected option to a form when editing a record.
I have set the form up as a component and am able to use it successfully when creating a new record, with the selected value being passed to the Rails backend.
My issue is that I cannot work out a way to apply this selected value to the form component when editing an existing record.
Here is the component template section (book-form.hbs):
<div class="form-group">
<select id="format" onchange={{action 'updateValue' value='target.value'}}>
<option value=""></option>
<option value="Paperback">Paperback</option>
<option value="Hardcover">Hardcover</option>
<option value="E-Book">E-Book</option>
</select>
Template code (book-form.js):
import Component from '#ember/component';
export default Component.extend({
actions: {
submitChange(param) {
this.onSave(param, this.selectedOpt);
},
selectedOpt: "",
updateValue(value) {
this.set('value', value);
this.selectedOpt = value;
},
}
});
new & edit templates:
{{book-form onSave=(action 'saveBook') model=model}}
new controller:
export default Controller.extend({
actions: {
saveBook(newBook,format) {
var tmp = this.store.createRecord('book', {
title: newBook.title,
author: newBook.author,
genre: newBook.genre,
format: format,
});
tmp.save();
this.transitionToRoute('books.list');
}
}
});
edit controller:
actions: {
saveBook(book) {
book.save();
this.transitionToRoute('books.list');
}
}
I know I'm missing something somewhere to pass the model value through to the component but am not sure how to do it or where it belongs.
I would appreciate any assistance at all.
If anyone looking at this question is using Ember Octane (3.14+)
This'd be what you want (based on #AhmetEmre's answer):
The Template:
<select id="format" {{on 'change' this.updateValue}}>
<option value=""></option>
<option value="Paperback" selected={{eq this.value "Paperback"}} >Paperback</option>
<option value="Hardcover" selected={{eq this.value "Hardcover"}} >Hardcover</option>
<option value="E-Book" selected={{eq this.value "E-Book"}}>E-Book</option>
</select>
The JS for the component:
import Component from '#glimmer/component';
import { tracked } from '#glimmer/tracking';
import { action } from '#ember/object';
export default class MyComponent extends Component {
#tracked value = 'Hardcover';
#action updateValue(event) {
this.value = event.target.value;
}
}
HTML select element's default value can be achieved by using selected argument in option tag.
So your template .hbs will be like:
<select id="format" onchange={{action 'updateValue'}}>
<option value=""></option>
<option value="Paperback" selected={{eq value "Paperback"}} >Paperback</option>
<option value="Hardcover" selected={{eq value "Hardcover"}} >Hardcover</option>
<option value="E-Book" selected={{eq value "E-Book"}}>E-Book</option>
</select>
and your component.js will be like:
value: 'Hardcover',
actions: {
updateValue(event){
this.set('value', event.target.value);
}
}
You can take a look at this twiddle for example usage. By the way, this example depends on ember-truth-helpers addon by using eq helper.

How to show different name of multiple selected options in select2.js

I am using select2.js, and i want to select multiple values that is working fine. But in selected values i don't want to show full content on selected text box, i want to show another content, like
<select id="event-users-dropdown" class="form-control" name="selectedUser[]" multiple="multiple">
<option data-id="123456" value="1"> 123456, my-name-here1 </option>
<option data-id="023456" value="2"> 023456, my-name-here2 </option>
<option data-id="003456" value="3"> 003456, my-name-here3 </option>
</select>
In this example i want to show only data-id (123456) values as selected content not '123456, my-name-here1'
I have completed this task.
$("ul.select2-selection__rendered li").each(function(){
var title = $(this).attr("title");
if(title){
title = title.substring(0, title.indexOf('-'));
// '-' is the character till that i want to use string, ex. (123 - my name)
var html = '<span class="select2-selection__choice__remove" role="presentation">×</span>';
$(this).html(html + title);
}
});

MVC 4 .NET use jquery to modify the set of options in a dropdown list

I am using #Html.DropDownListFor to build a select object that looks like this:
<select id="GroupCode" name="GroupCode" tabindex="4"><option value="">Select One</option>
<option value="1">One thing</option>
<option value="17">Another thing</option>
<option value="7">A Third thing</option>
</select>
There comes a time when something else changes on the page, and I want to swap out the options, ending up with something like
<select id="GroupCode" name="GroupCode" tabindex="4"><option value="">Select One</option>
<option value="21">A completely different list</option>
<option value="17">A second item only</option>
</select>
However, when I set a breakpoint in the view and look at $('#GroupCode').html, I see something like this:
$('#GroupCode').html
function(a){return p.access(this,function(a){var c=this[0]||{},d=0,e=this.length;if(a===b)return c.nodeType===1?c.innerHTML.replace(bm,""):b;if(typeof a=="string"&&!bs.test(a)&&(p.support.htmlSerialize||!bu.test(a))&&(p.support.leadingWhitespace||!bn.test(
__proto__:
function() {
[native code]
}
arguments: null
caller: null
length: 1
prototype: {...}
where I was expecting to see something like the html above.
What I'm concerned about is whether, by replacing the html for #GroupCode, I will lose what was provided by the #Html.DropDownFor code.
Bottom line: what is a good way to replace the contents of a dropdown list like this?
See this Working fiddle example
HTML
<select id="GroupCode" name="GroupCode" tabindex="4">
<option value="">Select One</option>
<option value="1">One thing</option>
<option value="17">Another thing</option>
<option value="7">A Third thing</option>
</select>
<button id="testBtn" type="button">replace list with items with ids (21, 7)</button>
Script:
$(function () {
$(document).on("click", "#testBtn", function () {
$('#GroupCode').empty().append(
$('<option/>', {
value: "",
text: 'Select One'
}),
$('<option/>', {
value: "21",
text: "A completely different list"
}),
$('<option/>', {
value: "17",
text: "A second item only"
}));
});
});

jQuery and Rails 3, what am I doing wrong?

I have a form which contains among others:
<form id="new_basic_ad" class="new_basic_ad" method="post" enctype="multipart/form-data" action="/basic_ads" accept-charset="UTF-8">
<select name="category_load_name" id="category_loader">
<option value="">Choose one</option>
<option value="1">First</option>
<option value="2">Second</option>
</select>
</form>
And I want to add client side validations. I tried adding this to my application.js:
$.validator.addMethod("valueNotEquals", function(value, element, arg){
return arg != value;
}, "Value must not equal arg.");
$("#new_basic_ad").validate({
rules: {
category_loader: {
valueNotEquals: "Choose one"
}
},
submitHandler:function(form) {
form.submit();
}
});
I want to make it so that the form cannot be submitted if the select is on the default ( Choose one ) value. However, my form is submitting ( without errors, apparently ), and I don't understand why it's not applying the validation. Should the validation be done on a live("submit",function(...)) ?
I was using the id of the element, instead of it's name. The code becomes now:
$("#new_basic_ad").validate({
rules: {
category_load_name: {
valueNotEquals: "Choose one"
}
},

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