I was wondering how to override the encapsulated CSS of an external component.
So I am using material2 in my project and the tabs component has a the attribute overflow set on tab-body. Is it possible to override the overflow value?
You can use the special css /deep/ instruction. See the documentation
So, if you have
app
sub-component
target-component
<div class="target-class">...</div>
You can put in your apps css (or less):
/deep/ .target-class {
width: 20px;
background: #ff0000;
}
Obviously, you can put this css fragment in sub-component as well.
From this article
Although the style of a component is well isolated, it can still be easily overridden if necessary. For that, we just need to add an attribute to the body of the page:
<body override>
<app></app>
</body>
The name of the attribute can be anything. No value is needed and the name override makes it apparent what its being used for. To override component styles, we can then do the following:
[override] hello-world h1 {
color:red;
}
Where override is the attribute, hello-world is the target component, and h1 is whatever you are trying to restyle. (get this right or it wont work).
Your component hello-world would be
selector: 'hello-world',
styles: [`
h1 {
color: blue;
}
`],
template: ` <h1>Hello world</h1> `
I think this is the most elegant way.
Alternatively if you are building a library of some sort, you can reset the styling altogether by doing something fancy in your css like:
:host-context(.custom-styles) {
//.. css here will only apply when there is a css class custom-styles in any parent elem
}
So then to use your component you'd use
<hello-world class="custom-styles">
But this is way less convenient than the first option.
::ng-deep .tag-or-css-class-you-want-to-override {
/* Add your custom css property value. */
}
The syntax ::ng-deep is used to override outside css class or tags without using ViewEncapsulation.None.
I see variations of this question a lot and since this is the top question on the subject I want to give the simplest answer. ng-deep and similar functionality is deprecated, so it's best to just rely on vanilla CSS.
Simply create a CSS selector with a higher specificity.
Most people (including myself) get hung up trying to do that because they don't understand two things:
Angular View Encapsulation
CSS Specificity
Angular View Encapsulation
View Encapsulation ensures CSS within a component only affects that component. To affect other components, you need some global CSS. You can do this by using a global style file like styles.css or by disabling View Encapsulation on a component.
#Component({
...
encapsulation: ViewEncapsulation.None
})
CSS Specificity
When two selectors select the same element, the CSS that actually gets applied is based on specificity: https://developer.mozilla.org/en-US/docs/Web/CSS/Specificity
You can increase specificity by simply adding more elements to your CSS selector. For example p.className is more specific than just .className. If you're lazy, you can just repeat a class name to increase specificity. .className.className is more specific than .className.
So to override any CSS in an Angular project, go into styles.css and repeat the class selector until your CSS has a higher specificity than the original.
.className.className.className {
color: red;
}
Didn't work? Add another .className.
Just check the class that is being applied to the tabs by the external component (use Inspector or any other tool). In your style css file, add the same name of the class for the tabs and set the overflow property along with adding !important to it to make sure it overwrites the previous one. Also make sure your css link to the page is added after the external component css link if any.
Hope this helps.
::ng-deep .css-class-you-want-to-override{
/*your custom css property value. like below */
background: white !important;
}
Related
I'm relatively new to Angular, and I have a doubt about component stylesheets.
I have an Angular 12 app and created a component named my-component. The template of the component in question is something like this:
my-component.html
<div>
...some html...
<some-other-angular-component></some-other-angular-component>
...some other html...
</div>
some-other-angular-component is another component, either from the app itself or a third party library.
Now, what I want to do in my-component is apply some CSS rules to the contents of some-other-angular-component. I know that the HTML it generates contains classes that I can target, so I tried to add this to my component CSS:
my-component.scss
.some-other-angular-component-inner-class {
background-color: red;
}
However, this doesn't work, it appears that the component's CSS file only applies rules to the HTML defined directly in the component's template, not the HTML generated by sub-components.
Is there a way to make this work? I find myself having to add my CSS to the webapp's main style.scss file, even when I want to apply the rule only to the particular some-other-angular-component instance inside of my-component. It makes styling confusing and needlessly fragmented. Is this intended, or what am I missing?
I think you may want to look into View Encapsulation.
#Component({
selector: 'app-no-encapsulation',
template: `
<h2>None</h2>
<div class="none-message">No encapsulation</div>
`,
styles: ['h2, .none-message { color: red; }'],
encapsulation: ViewEncapsulation.None,
})
export class NoEncapsulationComponent { }
These styles will be added to head and will be applicable to other components as well if style rule matches.
Please note, with this you are only enabling this behaviour for just this component. Chances of overlapping CSS rules is still there but is lot less in comparison to directly putting styles in style.css.
I will also suggest that you add .class or #id attribute in mark up to ensure that your rules don't overlap by default.
For example:
.my-component .rule-one {
}
It will ensure that my rules are only applied are on component that has this class applied on it.
I have two components with tab groups in them. One is a main page and I have overwritten the css to make the labels larger, done using ViewEncapsulation.None. The other is a dialog, and I want to keep it small but still apply some other custom styles to it.
When I open the dialog after visiting the other tabs page, it copies all the styles, which I have figured is because ViewEncapsulation.None bleeds CSS but not exactly as expected.
Is there anyway to override Angular Material styles without changing ViewEncapsulation so that I can keep the two components separate?
Solution 1: you can put all elements of your component into a parent element with a css class and override the material style into it.(it's custom capsulation)
Note: ViewEncapsulation is none here.
component.html
<div class="my-component__container">
<!-- other elements(material) are here -->
</div>
component.scss
.my-component__container{
// override material styles here
.mat-form-field{...}
}
Solution 2: use /deep/(deprecated).(use ::ng-depp insteaded)
:host /deep/ .mat-form-field {
text-align: left !important;
}
Solution 3: don't change ViewEncapsulation , then:
:host {
.my-component__container{}
}
if you would like to customise your Angular material components and provide your own stylings, I have the following suggestions. You may use one of them.
1) Overwrite the classes on your main style.css (or style.scss, whichever you are using). If you are wondering, it is the one that is on the same directory level as your index.html, main.ts, package.json, etc. You might need to add the !important declaration.
For instance,
.mat-form-field-label {
color:blue!important;
}
2) Customising the various Angular Material directive (such as MatPlaceholder) by providing a custom class.
For instance, when we use the MatPlaceHolder, and on the component.html template,
<mat-placeholder class="placeholder">Search</mat-placeholder>
On your component.css, we can then supply the css properties to the placehodler class
.placeholder {
color: green
}
Note:
Alternatively you may use ::ng-deep, but I would strongly suggest using ::ng-deep as it will soon be deprecated.
::ng-deep .mat-dialog {
/* styles here */
/* try not to use ::ng-deep */
}
You can use ::ng-deep. Refer NgDeep
How and where can one use ::ng-deep in Angular 4?
Actually I want to overwrite some of the CSS properties of the child components from the parent components. Moreover is it supported on IE11?
Usually /deep/ “shadow-piercing” combinator can be used to force a style down to child components. This selector had an alias >>> and now has another one called ::ng-deep.
since /deep/ combinator has been deprecated, it is recommended to use ::ng-deep
For example:
<div class="overview tab-pane" id="overview" role="tabpanel" [innerHTML]="project?.getContent( 'DETAILS')"></div>
and css
.overview {
::ng-deep {
p {
&:last-child {
margin-bottom: 0;
}
}
}
}
it will be applied to child components
I would emphasize the importance of limiting the ::ng-deep to only children of a component by requiring the parent to be an encapsulated css class.
For this to work it's important to use the ::ng-deep after the parent, not before otherwise it would apply to all the classes with the same name the moment the component is loaded.
Using the :host keyword before ::ng-deep will handle this automatically:
:host ::ng-deep .mat-checkbox-layout
Alternatively you can achieve the same behavior by adding a component scoped CSS class before the ::ng-deep keyword:
.my-component ::ng-deep .mat-checkbox-layout {
background-color: aqua;
}
Component template:
<h1 class="my-component">
<mat-checkbox ....></mat-checkbox>
</h1>
Resulting (Angular generated) css will then include the uniquely generated name and apply only to its own component instance:
.my-component[_ngcontent-c1] .mat-checkbox-layout {
background-color: aqua;
}
USAGE
::ng-deep, >>> and /deep/ disable view encapsulation for specific CSS rules, in other words, it gives you access to DOM elements, which are not in your component's HTML. For example, if you're using Angular Material (or any other third-party library like this), some generated elements are outside of your component's area (such as dialog) and you can't access those elements directly or using a regular CSS way. If you want to change the styles of those elements, you can use one of those three things, for example:
::ng-deep .mat-dialog {
/* styles here */
}
For now Angular team recommends making "deep" manipulations only with EMULATED view encapsulation.
DEPRECATION
"deep" manipulations are actually deprecated too, BUT it's still working for now, because Angular does pre-processing support (don't rush to refuse ::ng-deep today, take a look at deprecation practices first).
Anyway, before following this way, I recommend you to take a look at disabling view encapsulation approach (which is not ideal too, it allows your styles to leak into other components), but in some cases, it's a better way. If you decided to disable view encapsulation, it's strongly recommended to use specific classes to avoid CSS rules intersection, and finally, avoid a mess in your stylesheets. It's really easy to disable right in the component's .ts file:
#Component({
selector: '',
template: '',
styles: [''],
encapsulation: ViewEncapsulation.None // Use to disable CSS Encapsulation for this component
})
You can find more info about the view encapsulation in this article.
Make sure not to miss the explanation of :host-context which is directly above ::ng-deep in the angular guide : https://angular.io/guide/component-styles. I missed it up until now and wish I'd seen it sooner.
::ng-deep is often necessary when you didn't write the component and don't have access to its source, but :host-context can be a very useful option when you do.
For example I have a black <h1> header inside a component I designed, and I want the ability to change it to white when it's displayed on a dark themed background.
If I didn't have access to the source I may have to do this in the css for the parent:
.theme-dark widget-box ::ng-deep h1 { color: white; }
But instead with :host-context you can do this inside the component.
h1
{
color: black; // default color
:host-context(.theme-dark) &
{
color: white; // color for dark-theme
}
// OR set an attribute 'outside' with [attr.theme]="'dark'"
:host-context([theme='dark']) &
{
color: white; // color for dark-theme
}
}
This will look anywhere in the component chain for .theme-dark and apply the css to the h1 if found. This is a good alternative to relying too much on ::ng-deep which while often necessary is somewhat of an anti-pattern.
In this case the & is replaced by the h1 (that's how sass/scss works) so you can define your 'normal' and themed/alternative css right next to each other which is very handy.
Be careful to get the correct number of :. For ::ng-deep there are two and for :host-context only one.
Just an update:
You should use ::ng-deep instead of /deep/ which seems to be deprecated.
Per documentation:
The shadow-piercing descendant combinator is deprecated and support is
being removed from major browsers and tools. As such we plan to drop
support in Angular (for all 3 of /deep/, >>> and ::ng-deep). Until
then ::ng-deep should be preferred for a broader compatibility with
the tools.
You can find it here
I looked through all those answers and found nobody mentioned a child component can pass a style CSS in from its parent.
In component ts file, you can use this:
#Input() styles: any = {};
In component html file, you use this:
[ngStyle]="styles"
in parent, you use this :
<yourComponent [styles]="{backgroundColor: 'blue', 'font-size': '16px'}">
Please see more details here: Best way to pass styling to a component
In this way, we didn't break encapsulation, which is one of those most important Object orientation principles
Use ::ng-deep with caution. I used it throughout my app to set the material design toolbar color to different colors throughout my app only to find that when the app was in testing the toolbar colors step on each other. Come to find out it is because these styles becomes global, see this article Here is a working code solution that doesn't bleed into other components.
<mat-toolbar #subbar>
...
</mat-toolbar>
export class BypartSubBarComponent implements AfterViewInit {
#ViewChild('subbar', { static: false }) subbar: MatToolbar;
constructor(
private renderer: Renderer2) { }
ngAfterViewInit() {
this.renderer.setStyle(
this.subbar._elementRef.nativeElement, 'backgroundColor', 'red');
}
}
Given a typical Angular Material dialog, which has a max-width of 80vw set on .mat-dialog-container, how can I formulate a selector to override it? I'd like a true full-width dialog.
The problem is scoping--Angular-CLI compiles component CSS with scope attribute selectors.
Therefore, this:
.parent .child
becomes:
.parent[some_attr] .child[some_other_attr]
However, this particular element doesn't seem attached to any component--it doesn't have a dynamically-generated attribute on it.
I've attempted overrides in both the dialog stylesheet and the host component's stylesheet with no success.
Angular special selectors
Dialog Plunkr
Let me try again. I'm not doing a good job of explaining the issue.
Let's say I add this to my host component stylesheet:
.mat-dialog-container {
max-width: 100%;
}
I have a build watch running, so the app is recompiled. The CSS output is now this:
.mat-dialog-container[_ngcontent-c6] {
max-width: 100%;
}
However, that element doesn't actually have the attribute _ngcontent-c6 on it. That attribute is applied to other elements which are inside siblings of ancestors of .mat-dialog-container. The selector is just wrong.
If I add that CSS to the dialog component's stylesheet, something similar happens, but with a different attribute ID.
If you can add an id to your main body tag and you want it to be on all of these dialogs you can use this
<style>
#bodyID .mat-dialog-container {
max-width:100vw;
background-color: blue;
}
</style>
It will override the current style, at least in the plunker you supplied.
If you need specific style for each dialog, did you look into this?
how-to-style-child-components-from-parent-components-css-file
You don't need a body id, because as you've mentioned the selector is rewritten by Angular such that it stops matching the element altogether.
But yeah it seems the only way around this is to just throw your hands up and forget about component stylesheet scoping and add your CSS rule to the page stylesheet. The caveat, of course, is that this rule needs to be added to every page that uses the component, which can be seen as absurd depending on what your component is intended to be used for and by whom.
What are all the css style classes that has to be changed to restyle dojo filtering select ?
Note: I am using claro theme.
I want to
1.Set the style for one particular filteringselect with id QuickSearchPane_SelectBox
2.Set the style for all other filteringselect
I found a few like:
.claro .dijitTextBox .dijitInputInner
.claro .dijitInputField .dijitPlaceHolder
.claro .dijitSelect
But these are not giving the desired effect. I am not even able to change the background colors.
For Menu
[dijitpopupparent="QuickSearchPane_SelectBox"] > .dijitComboBoxMenu .dijitMenuItem
This seems to work.
You can use the following CSS class to start styling your dijit/form/FilteringSelect;
This example will style all instance of dijit/form/FilteringSelect:
https://jsfiddle.net/ofgcd24n/
.dijitInputInner {
background-color: green !important;
}
.dijitMenuItem {
background-color: orange;
}
This other example below will style only ONE instance of dijit/form/FilteringSelect, please note the use of Descendant combinator as selector (where you use the ID for your widget DOM):
#widget_stateSelect .dijitInputInner {
/* your style*/
}
Generally you can use (in Chrome Dev Tool) Event Listen Breakpoints for click/mouse down, so when you open you FilteringSelect, you can block execution, and check with the inspector its HTML structure and see additional CSS classes you want to override with your styles.
More about CSS selector:
https://www.w3.org/TR/css3-selectors/
If you need more details, please post your HTML and CSS and desired layout so we can work out a specific solution.