Related
I am using the Grid component and have a cellRenderer. In it I attempt to add a backgroundColor style to the outer div.
customColumnRenderer(props: GridCellProps): React.ReactNode {
...
props.style.backgroundColor = "hotpink";
...
return <div style={props.style}
... </div>;
}
All is good at first, but then I scroll vertically a bit and I get this exception:
Uncaught TypeError: Cannot assign to read only property 'backgroundColor' of object '#<Object>'
When I look in the debugger. props.style looks like a simple Object to me. The doc says
"You can add additional class names or style properties as you would like."
Any thoughts on what I might be doing wrong?
Best workaround I could come up with is to merge in style props from a different object using the spread operator. Something like this:
customColumnRenderer(props: GridCellProps): React.ReactNode {
...
let myStyles = {backgroundColor: "hotpink"};
let styles = {...props.style, ...myStyles};
...
return <div style={styles}
... </div>;
}
I'm using the following markup to mark the clicked component as active.
<div *ngFor="let menu of menus;"
(click)="onClick($event,menu.link)"
[ngClass]="{'active':menu.active}">
{{menu.title}}
</div>
The method handling the click is as follows.
onClick(target, link) {
target.active = !target.active;
this.router.navigate([{ outlets: { primary: [""], menus: [link] } }]);
}
It seems that the value of target.active goes from undefined to true to false to true etc. but the style doesn't get set. (I'm printing out the whole component to the console and can't see the addition of the class' name.)
Question: What am I missing in this approach?
NB, I know how to resolve it by approaching it from a different angle. I set up a local variable keeping the index and setting it like shown here. The aim of my question is to learn to achieve the requested behavior in a more like-a-bossy way.
target here:
onClick(target, link) {
target.active = !target.active; <------------
this.router.navigate([{ outlets: { primary: [""], menus: [link] } }]);
}
doesn't refer to menu, it refers to the event. But based on your ngClass directive:
[ngClass]="{'active':menu.active}">
You need to set active to menu variable and so it can be done like this:
<div *ngFor="let menu of menus;"
(click)="onClick(menu,menu.link)"
[ngClass]="{'active':menu.active}">
{{menu.title}}
</div>
Instead of passing in the $event, send it the actual menu object. Like this:
<div *ngFor="let menu of menus;"
(click)="onClick(menu)"
[ngClass]="{'active':menu.active}">
{{menu.title}}
</div>
And in the component:
onClick(menu) {
menu.active = !menu.active;
this.router.navigate([{ outlets: { primary: [""], menus: [menu.link] } }]);
}
I've read around a little bit and have a good start to what I ultimately want. This was helpful, along with another article which I forgot the link to. However, everything I've read ADDS a CSS class or property to an element. I want to CHANGE a property of an existing CSS class, but I don't know how to target it.
I think I want to use ng-class in one of these use cases taken from the Angular documentation:
If the expression evaluates to a string, the string should be one or more space-delimited class names.
If the expression evaluates to an object, then for each key-value pair of the object with a truthy value the corresponding key is used as a class name.
My existing code uses ng-class along with some controller logic.
HTML
<div ng-controller="ngToggle">
<div ng-class="{'inset-gray-border' : style}">
<div class="subcontainer" ng-click="toggleStyle()">{{item.name}}</div>
</div>
</div>
This currently adds the inset-gray-border class to the nested div, but I just want to change the border property in the subcontainer class.
Controller
angular.module('app').controller('ngToggle', ['$scope', function($scope) {
$scope.style = false;
$scope.toggleStyle = function() {
$scope.style = $scope.style === false ? true: false;
};
}]);
I considered using a directive, but I believe that would be overkill. I think this can be achieved in a controller.
EDIT: After further research I think jQLite can do the trick, but that would probably require a directive.
CHANGE a property of an existing CSS class
Add a css rule that does that using the new class you added using ng-class. The specificity will over ride the original rule
.subcontainer{
color : blue
}
.inset-gray-border .subcontainer{
color:red
}
Instead of a big toggleStyle function, you can write that stuff in UI side only.
Here is fiddle. As you want to change border property of .subcontainer, Overwrite that property by adding .insert-gray-border
<div ng-controller="ngToggle">
<div >
<div ng-class="{'subcontainer':true,'inset-gray-border' : style}" ng-click="style=!style">{{item.name}}</div>
</div>
</div>
The benifit of this is , it uses local scope instead of controller scope.
The best bet would be to have two CSS classes defined, one for the base (untoggled) case, another with all the properties that you want for when the property is toggled on.
In this case you may want something like:
.container .subcontainer {}
.container .subcontainer-bordered { border: solid 1px #123456}
Then your HTML code be updated to reflect this structure
<div ng-controller="ngToggle">
<div class="container">
<div class="subcontainer" ng-class="{'subcontainer-bordered': style}" ng-click="style = !style">{{item.name}}</div>
</div>
</div>
Q1. Suppose I want to alter the look of each "item" that a user marks for deletion before the main "delete" button is pressed. (This immediate visual feedback should eliminate the need for the proverbial "are you sure?" dialog box.) The user will check checkboxes to indicate which items should be deleted. If a checkbox is unchecked, that item should revert back to its normal look.
What's the best way to apply or remove the CSS styling?
Q2. Suppose I want to allow each user to personalize how my site is presented. E.g., select from a fixed set of font sizes, allow user-definable foreground and background colors, etc.
What's the best way to apply the CSS styling the user selects/inputs?
Angular provides a number of built-in directives for manipulating CSS styling conditionally/dynamically:
ng-class - use when the set of CSS styles is static/known ahead of time
ng-style - use when you can't define a CSS class because the style values may change dynamically. Think programmable control of the style values.
ng-show and ng-hide - use if you only need to show or hide something (modifies CSS)
ng-if - new in version 1.1.5, use instead of the more verbose ng-switch if you only need to check for a single condition (modifies DOM)
ng-switch - use instead of using several mutually exclusive ng-shows (modifies DOM)
ng-disabled and ng-readonly - use to restrict form element behavior
ng-animate - new in version 1.1.4, use to add CSS3 transitions/animations
The normal "Angular way" involves tying a model/scope property to a UI element that will accept user input/manipulation (i.e., use ng-model), and then associating that model property to one of the built-in directives mentioned above.
When the user changes the UI, Angular will automatically update the associated elements on the page.
Q1 sounds like a good case for ng-class -- the CSS styling can be captured in a class.
ng-class accepts an "expression" that must evaluate to one of the following:
a string of space-delimited class names
an array of class names
a map/object of class names to boolean values
Assuming your items are displayed using ng-repeat over some array model, and that when the checkbox for an item is checked you want to apply the pending-delete class:
<div ng-repeat="item in items" ng-class="{'pending-delete': item.checked}">
... HTML to display the item ...
<input type="checkbox" ng-model="item.checked">
</div>
Above, we used ng-class expression type #3 - a map/object of class names to boolean values.
Q2 sounds like a good case for ng-style -- the CSS styling is dynamic, so we can't define a class for this.
ng-style accepts an "expression" that must evaluate to:
an map/object of CSS style names to CSS values
For a contrived example, suppose the user can type in a color name into a texbox for the background color (a jQuery color picker would be much nicer):
<div class="main-body" ng-style="{color: myColor}">
...
<input type="text" ng-model="myColor" placeholder="enter a color name">
Fiddle for both of the above.
The fiddle also contains an example of ng-show and ng-hide. If a checkbox is checked, in addition to the background-color turning pink, some text is shown. If 'red' is entered in the textbox, a div becomes hidden.
I have found problems when applying classes inside table elements when I had one class already applied to the whole table (for example, a color applied to the odd rows <myClass tbody tr:nth-child(even) td>). It seems that when you inspect the element with Developer Tools, the element.style has no style assigned. So instead of using ng-class, I have tried using ng-style, and in this case, the new CSS attribute does appear inside element.style. This code works great for me:
<tr ng-repeat="element in collection">
[...amazing code...]
<td ng-style="myvar === 0 && {'background-color': 'red'} ||
myvar === 1 && {'background-color': 'green'} ||
myvar === 2 && {'background-color': 'yellow'}">{{ myvar }}</td>
[...more amazing code...]
</tr>
Myvar is what I am evaluating, and in each case I apply a style to each <td> depending on myvar value, that overwrites the current style applied by the CSS class for the whole table.
UPDATE
If you want to apply a class to the table for example, when visiting a page or in other cases, you can use this structure:
<li ng-class="{ active: isActive('/route_a') || isActive('/route_b')}">
Basically, what we need to activate a ng-class is the class to apply and a true or false statement. True applies the class and false doesn't. So here we have two checks of the route of the page and an OR between them, so if we are in /route_a OR we are in route_b, the active class will be applied.
This works just having a logic function on the right that returns true or false.
So in the first example, ng-style is conditioned by three statements. If all of them are false, no style is applied, but following our logic, at least one is going to be applied, so, the logic expression will check which variable comparison is true and because a non empty array is always true, that will left an array as return and with only one true, considering we are using OR for the whole response, the style remaining will be applied.
By the way, I forgot to give you the function isActive():
$rootScope.isActive = function(viewLocation) {
return viewLocation === $location.path();
};
NEW UPDATE
Here you have something I find really useful. When you need to apply a class depending on the value of a variable, for example, an icon depending on the contents of the div, you can use the following code (very useful in ng-repeat):
<i class="fa" ng-class="{ 'fa-github' : type === 0,
'fa-linkedin' : type === 1,
'fa-skype' : type === 2,
'fa-google' : type === 3 }"></i>
Icons from Font Awesome
This works well when ng-class can't be used (for example when styling SVG):
ng-attr-class="{{someBoolean && 'class-when-true' || 'class-when-false' }}"
(I think you need to be on latest unstable Angular to use ng-attr-, I'm currently on 1.1.4)
I have published an article on working with AngularJS+SVG. It talks about this issue and numerous others. http://www.codeproject.com/Articles/709340/Implementing-a-Flowchart-with-SVG-and-AngularJS
span class="circle circle-{{selectcss(document.Extension)}}">
and code
$scope.selectcss = function (data) {
if (data == '.pdf')
return 'circle circle-pdf';
else
return 'circle circle-small';
};
css
.circle-pdf {
width: 24px;
height: 24px;
font-size: 16px;
font-weight: 700;
padding-top: 3px;
-webkit-border-radius: 12px;
-moz-border-radius: 12px;
border-radius: 12px;
background-image: url(images/pdf_icon32.png);
}
This solution did the trick for me
<a ng-style="{true: {paddingLeft: '25px'}, false: {}}[deleteTriggered]">...</a>
You can use ternary expression. There are two ways to do this:
<div ng-style="myVariable > 100 ? {'color': 'red'} : {'color': 'blue'}"></div>
or...
<div ng-style="{'color': (myVariable > 100) ? 'red' : 'blue' }"></div>
Another option when you need a simple css style of one or two properties:
View:
<tr ng-repeat="element in collection">
[...amazing code...]
<td ng-style="{'background-color': getTrColor(element.myvar)}">
{{ element.myvar }}
</td>
[...more amazing code...]
</tr>
Controller:
$scope.getTrColor = function (colorIndex) {
switch(colorIndex){
case 0: return 'red';
case 1: return 'green';
default: return 'yellow';
}
};
See the following example
<!DOCTYPE html>
<html ng-app>
<head>
<title>Demo Changing CSS Classes Conditionally with Angular</title>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.7/angular.min.js"></script>
<script src="res/js/controllers.js"></script>
<style>
.checkboxList {
border:1px solid #000;
background-color:#fff;
color:#000;
width:300px;
height: 100px;
overflow-y: scroll;
}
.uncheckedClass {
background-color:#eeeeee;
color:black;
}
.checkedClass {
background-color:#3ab44a;
color:white;
}
</style>
</head>
<body ng-controller="TeamListCtrl">
<b>Teams</b>
<div id="teamCheckboxList" class="checkboxList">
<div class="uncheckedClass" ng-repeat="team in teams" ng-class="{'checkedClass': team.isChecked, 'uncheckedClass': !team.isChecked}">
<label>
<input type="checkbox" ng-model="team.isChecked" />
<span>{{team.name}}</span>
</label>
</div>
</div>
</body>
</html>
As of AngularJS v1.2.0rc, ng-class and even ng-attr-class fail with SVG elements (They did work earlier, even with normal binding inside the class attribute)
Specifically, none of these work now:
ng-class="current==this_element?'active':' ' "
ng-attr-class="{{current==this_element?'active':' '}}"
class="class1 class2 .... {{current==this_element?'active':''}}"
As a workaround, I've to use
ng-attr-otherAttr="{{current==this_element?'active':''}}"
and then style using
[otherAttr='active'] {
... styles ...
}
One more (in the future) way to conditionally apply style is by conditionally creating scoped style
<style scoped type="text/css" ng-if="...">
</style>
But nowadays only FireFox supports scoped styles.
There is one more option that I recently discovered that some people may find useful because it allows you to change a CSS rule within a style element - thus avoiding the need for repeated use of an angular directive such as ng-style, ng-class, ng-show, ng-hide, ng-animate, and others.
This option makes use of a service with service variables which are set by a controller and watched by an attribute-directive I call "custom-style". This strategy could be used in many different ways, and I attempted to provide some general guidance with this fiddle.
var app = angular.module('myApp', ['ui.bootstrap']);
app.service('MainService', function(){
var vm = this;
});
app.controller('MainCtrl', function(MainService){
var vm = this;
vm.ms = MainService;
});
app.directive('customStyle', function(MainService){
return {
restrict : 'A',
link : function(scope, element, attr){
var style = angular.element('<style></style>');
element.append(style);
scope.$watch(function(){ return MainService.theme; },
function(){
var css = '';
angular.forEach(MainService.theme, function(selector, key){
angular.forEach(MainService.theme[key], function(val, k){
css += key + ' { '+k+' : '+val+'} ';
});
});
style.html(css);
}, true);
}
};
});
well i would suggest you to check condition in your controller with a function returning true or false .
<div class="week-wrap" ng-class="{today: getTodayForHighLight(todayDate, day.date)}">{{day.date}}</div>
and in your controller check the condition
$scope.getTodayForHighLight = function(today, date){
return (today == date);
}
One thing to watch is - if the CSS style has dashes - you must remove them. So if you want to set background-color, the correct way is:
ng-style="{backgroundColor:myColor}"
Here's how i conditionally applied gray text style on a disabled button
import { Component } from '#angular/core';
#Component({
selector: 'my-app',
styleUrls: [ './app.component.css' ],
template: `
<button
(click)='buttonClick1()'
[disabled] = "btnDisabled"
[ngStyle]="{'color': (btnDisabled)? 'gray': 'black'}">
{{btnText}}
</button>`
})
export class AppComponent {
name = 'Angular';
btnText = 'Click me';
btnDisabled = false;
buttonClick1() {
this.btnDisabled = true;
this.btnText = 'you clicked me';
setTimeout(() => {
this.btnText = 'click me again';
this.btnDisabled = false
}, 5000);
}
}
Here's a working example:
https://stackblitz.com/edit/example-conditional-disable-button?file=src%2Fapp%2Fapp.component.html
Lets say you have an array that is rendered in a ul with an li for each element and a property on the controller called selectedIndex. What would be the best way to add a class to the li with the index selectedIndex in AngularJS?
I am currently duplicating (by hand) the li code and adding the class to one of the li tags and using ng-show and ng-hide to show only one li per index.
If you don't want to put CSS class names into Controller like I do, here is an old trick that I use since pre-v1 days. We can write an expression that evaluates directly to a class name selected, no custom directives are necessary:
ng:class="{true:'selected', false:''}[$index==selectedIndex]"
Please note the old syntax with colon.
There is also a new better way of applying classes conditionally, like:
ng-class="{selected: $index==selectedIndex}"
Angular now supports expressions that return an object. Each property (name) of this object is now considered as a class name and is applied depending on its value.
However these ways are not functionally equal. Here is an example:
ng-class="{admin:'enabled', moderator:'disabled', '':'hidden'}[user.role]"
We could therefore reuse existing CSS classes by basically mapping a model property to a class name and at the same time keep CSS classes out of Controller code.
ng-class supports an expression that must evaluate to either
A string of space-delimited class names, or
An array of class names, or
A map/object of class names to boolean values.
So, using form 3) we can simply write
ng-class="{'selected': $index==selectedIndex}"
See also How do I conditionally apply CSS styles in AngularJS? for a broader answer.
Update: Angular 1.1.5 has added support for a ternary operator, so if that construct is more familiar to you:
ng-class="($index==selectedIndex) ? 'selected' : ''"
My favorite method is using the ternary expression.
ng-class="condition ? 'trueClass' : 'falseClass'"
Note: Incase you're using a older version of Angular you should use this instead,
ng-class="condition && 'trueClass' || 'falseClass'"
I'll add to this, because some of these answers seem out of date. Here's how I do it:
<class="ng-class:isSelected">
Where 'isSelected' is a javascript variable defined within the scoped angular controller.
To more specifically address your question, here's how you might generate a list with that:
HTML
<div ng-controller="ListCtrl">
<li class="ng-class:item.isSelected" ng-repeat="item in list">
{{item.name}}
</li>
</div>
JS
function ListCtrl($scope) {
$scope.list = [
{"name": "Item 1", "isSelected": "active"},
{"name": "Item 2", "isSelected": ""}
]
}
See: http://jsfiddle.net/tTfWM/
See: http://docs.angularjs.org/api/ng.directive:ngClass
Here is a much simpler solution:
function MyControl($scope){
$scope.values = ["a","b","c","d","e","f"];
$scope.selectedIndex = -1;
$scope.toggleSelect = function(ind){
if( ind === $scope.selectedIndex ){
$scope.selectedIndex = -1;
} else{
$scope.selectedIndex = ind;
}
}
$scope.getClass = function(ind){
if( ind === $scope.selectedIndex ){
return "selected";
} else{
return "";
}
}
$scope.getButtonLabel = function(ind){
if( ind === $scope.selectedIndex ){
return "Deselect";
} else{
return "Select";
}
}
}
.selected {
color:red;
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.1/angular.min.js"></script>
<div ng-app ng-controller="MyControl">
<ul>
<li ng-class="getClass($index)" ng-repeat="value in values" >{{value}} <button ng-click="toggleSelect($index)">{{getButtonLabel($index)}}</button></li>
</ul>
<p>Selected: {{selectedIndex}}</p>
</div>
I faced a similar problem recently and decided to just create a conditional filter:
angular.module('myFilters', []).
/**
* "if" filter
* Simple filter useful for conditionally applying CSS classes and decouple
* view from controller
*/
filter('if', function() {
return function(input, value) {
if (typeof(input) === 'string') {
input = [input, ''];
}
return value? input[0] : input[1];
};
});
It takes a single argument, which is either a 2-element array or a string, which gets turned into an array that is appended an empty string as the second element:
<li ng-repeat="item in products | filter:search | orderBy:orderProp |
page:pageNum:pageLength" ng-class="'opened'|if:isOpen(item)">
...
</li>
If you want to go beyond binary evaluation and keep your CSS out of your controller you can implement a simple filter that evaluates the input against a map object:
angular.module('myApp.filters, [])
.filter('switch', function () {
return function (input, map) {
return map[input] || '';
};
});
This allows you to write your markup like this:
<div ng-class="muppets.star|switch:{'Kermit':'green', 'Miss Piggy': 'pink', 'Animal': 'loud'}">
...
</div>
The was I recently did that was doing this:
<input type="password" placeholder="Enter your password"
ng-class="{true: 'form-control isActive', false: 'isNotActive'}[isShowing]">
The isShowing value is a value that is located on my controller that gets toggled with the click of a button and the parts between the single parenthesis are classes I created in my css file.
EDIT: I would also like to add that codeschool.com has a free course that is sponsored by google on AngularJS that goes over all of this stuff and then some. There is no need to pay for anything, just signup for an account and get going!
Best of luck to you all!
Ternary operator has just been added to angular parser in 1.1.5.
So the simplest way to do this is now :
ng:class="($index==selectedIndex)? 'selected' : ''"
We can make a function to manage return class with condition
<script>
angular.module('myapp', [])
.controller('ExampleController', ['$scope', function ($scope) {
$scope.MyColors = ['It is Red', 'It is Yellow', 'It is Blue', 'It is Green', 'It is Gray'];
$scope.getClass = function (strValue) {
switch(strValue) {
case "It is Red":return "Red";break;
case "It is Yellow":return "Yellow";break;
case "It is Blue":return "Blue";break;
case "It is Green":return "Green";break;
case "It is Gray":return "Gray";break;
}
}
}]);
</script>
And then
<body ng-app="myapp" ng-controller="ExampleController">
<h2>AngularJS ng-class if example</h2>
<ul >
<li ng-repeat="icolor in MyColors" >
<p ng-class="[getClass(icolor), 'b']">{{icolor}}</p>
</li>
</ul>
<hr/>
<p>Other way using : ng-class="{'class1' : expression1, 'class2' : expression2,'class3':expression2,...}"</p>
<ul>
<li ng-repeat="icolor in MyColors">
<p ng-class="{'Red':icolor=='It is Red','Yellow':icolor=='It is Yellow','Blue':icolor=='It is Blue','Green':icolor=='It is Green','Gray':icolor=='It is Gray'}" class="b">{{icolor}}</p>
</li>
</ul>
You can refer to full code page at ng-class if example
I am new to Angular but have found this to solve my issue:
<i class="icon-download" ng-click="showDetails = ! showDetails" ng-class="{'icon-upload': showDetails}"></i>
This will conditionally apply a class based on a var.
It starts off with a icon-download as a default, the using ng-class, I check the status of showDetails if true/false and apply class icon-upload. Its working great.
Hope it helps.
This works like a charm ;)
<ul class="nav nav-pills" ng-init="selectedType = 'return'">
<li role="presentation" ng-class="{'active':selectedType === 'return'}"
ng-click="selectedType = 'return'"><a href="#return">return
</a></li>
<li role="presentation" ng-class="{'active':selectedType === 'oneway'}"
ng-click="selectedType = 'oneway'"><a href="#oneway">oneway
</a></li>
</ul>
This will probably get downvoted to oblivion, but here is how I used 1.1.5's ternary operators to switch classes depending on whether a row in a table is the first, middle or last -- except if there is only one row in the table:
<span class="attribute-row" ng-class="(restaurant.Attributes.length === 1) || ($first ? 'attribute-first-row': false || $middle ? 'attribute-middle-row': false || $last ? 'attribute-last-row': false)">
</span>
This is in my work multiple conditionally judge:
<li ng-repeat='eOption in exam.examOptions' ng-class="exam.examTitle.ANSWER_COM==exam.examTitle.RIGHT_ANSWER?(eOption.eoSequence==exam.examTitle.ANSWER_COM?'right':''):eOption.eoSequence==exam.examTitle.ANSWER_COM?'wrong':eOption.eoSequence==exam.examTitle.RIGHT_ANSWER?'right':''">
<strong>{{eOption.eoSequence}}</strong> |
<span ng-bind-html="eOption.eoName | to_trusted">2020 元</span>
</li>
Here is another option that works well when ng-class can't be used (for example when styling SVG):
ng-attr-class="{{someBoolean && 'class-when-true' || 'class-when-false' }}"
(I think you need to be on latest unstable Angular to use ng-attr-, I'm currently on 1.1.4)
well i would suggest you to check condition in your controller with a function returning true or false .
<div class="week-wrap" ng-class="{today: getTodayForHighLight(todayDate, day.date)}">{{day.date}}</div>
and in your controller check the condition
$scope.getTodayForHighLight = function(today, date){
return (today == date);
}
partial
<div class="col-md-4 text-right">
<a ng-class="campaign_range === 'thismonth' ? 'btn btn-blue' : 'btn btn-link'" href="#" ng-click='change_range("thismonth")'>This Month</a>
<a ng-class="campaign_range === 'all' ? 'btn btn-blue' : 'btn btn-link'" href="#" ng-click='change_range("all")'>All Time</a>
</div>
controller
$scope.campaign_range = "all";
$scope.change_range = function(range) {
if (range === "all")
{
$scope.campaign_range = "all"
}
else
{
$scope.campaign_range = "thismonth"
}
};
If you are using angular pre v1.1.5 (i.e. no ternary operator) and you still want an equivalent way to set a value in both conditions you can do something like this:
ng-class="{'class1':item.isReadOnly == false, 'class2':item.isReadOnly == true}"
If you having a common class that is applied to many elements you can create a custom directive that will add that class like ng-show/ng-hide.
This directive will add the class 'active' to the button if it's clicked
module.directive('ngActive', ['$animate', function($animate) {
return function(scope, element, attr) {
scope.$watch(attr.ngActive, function ngActiveWatchAction(value){
$animate[value ? 'addClass' : 'removeClass'](element, 'active');
});
};
}]);
More info
Just adding something that worked for me today, after much searching...
<div class="form-group" ng-class="{true: 'has-error'}[ctrl.submitted && myForm.myField.$error.required]">
Hope this assists in your successful development.
=)
Undocumented Expression Syntax : Great Website Link... =)
Check this.
The infamous AngularJS if|else statement!!!
When I started using Angularjs, I was a bit surprised that I couldn’t find an if/else statement.
So I was working on a project and I noticed that when using the if/else statement, the condition shows while loading.
You can use ng-cloak to fix this.
<div class="ng-cloak">
<p ng-show="statement">Show this line</span>
<p ng-hide="statement">Show this line instead</span>
</div>
.ng-cloak { display: none }
Thanks amadou
You can use this npm package. It handles everything and has options for static and conditional classes based on a variable or a function.
// Support for string arguments
getClassNames('class1', 'class2');
// support for Object
getClassNames({class1: true, class2 : false});
// support for all type of data
getClassNames('class1', 'class2', ['class3', 'class4'], {
class5 : function() { return false; },
class6 : function() { return true; }
});
<div className={getClassNames({class1: true, class2 : false})} />
I understand this question id for angular, but if anyone is using React or a React-Based Framework (Amplify, NextJS, Serverless, etc.) The solution is significantly easier. The most performant way is with a ternary operator like so:
<div className={condition ? "classnameiftrue" : "classnameiffalse"}>
You can use this strategy to animate the tree if using useState() as each time the state changes it will reload that conditional with the new value.