How come modifying the css of one component impacts all the other components?

Issue: I am struggling to make CSS changes only affect the specific component I want, without impacting other elements on the page. My goal is to style my dropdown menu without affecting other text input fields:

https://i.sstatic.net/Caidv.png

Background/Challenge: While I understand why the styling would apply to all similar items within the same page (mat-form-field's), I'm puzzled as to why it extends to affect other pages as well. I have tried to investigate this issue but remain uncertain about the cause.

Approach Taken: In one instance, I had implemented the following CSS code:

::ng-deep .mat-form-field-appearance-outline .mat-form-field-flex {
    height: 40px !important
}

::ng-deep .mat-form-field-infix {
    padding-top: 1px !important;
    padding-bottom: 2px !important;
}

However, this ended up modifying the spacing of all form-fields on the page, prompting me to revise it as follows:

::ng-deep .mat-form-field-appearance-outline .mat-form-field-flex {
    height: 40px !important
}

::ng-deep .mat-form-field-appearance-outline .mat-form-field-infix {
    padding-top: 1px !important;
    padding-bottom: 2px !important;
}

Other sections of unchanged CSS include:

.title-container {
    position: relative;
    margin-top: 8px;
}

.language-field {
    position: absolute;
    right: 0;
    top: 0;
    margin-top: -16px;
    width: 115px;
    height: 20px !important;
}

Although this revision addressed the issue, I find it perplexing that altering the login.component.css impacts other pages like profile.component.css

Below is the HTML associated with the login.component:

<div class="title-container">
    <mat-card-title class="text-center">
        Please Sign In
    </mat-card-title>

    <form [formGroup]="_siteForm">
        <mat-form-field class="language-field" appearance="outline">
            <mat-select (selectionChange)="changeSite($event)" [value]="languages[i].value">
                <mat-option *ngFor="let language of languages" [value]="language.value">
                    {{language.viewValue}}
                </mat-option>
            </mat-select>
        </mat-form-field>
    </form>        
</div> 

Research Findings: I came across several Stack Overflow articles (like Angular 2+ : Component style keeps affecting other components) suggesting the use of encapsulation through ViewEncapsulation. However, after examining the project files, I noticed that encapsulation was not explicitly utilized anywhere. Each component had CSS styles referencing mat-form-field with different values, which could imply that encapsulation may not be necessary. I never encountered such issues in regular HTML development, and I am trying to grasp how Angular manages these scenarios. Could this behavior be related to Angular functioning as a Single Page Application (SPA)?

Answer №1

To resolve this issue, I suggest removing the ::ng-deep element first.

Next, create a unique class name and define it in the components css file. For example, in app.component.css

.custom-input-field {
    width: 200px !important;
}

Answer №2

Understanding the concept you're trying to convey here is a bit challenging without a code snippet featuring that CSS.

If it's disrupting Angular's default view encapsulation for all components, the issue likely stems from your use of !important selectors, which should only be employed in exceptional cases - https://developer.mozilla.org/en-US/docs/Web/CSS/Specificity

The reason being, the use of !important disrupts the css specificity that Angular relies on to encapsulate its components.

Css specificity functions as follows:

Inline styles hold a value of 1000pts

Id's are valued at 100pts

Classes are given 10pts

Elements carry a point value of 1pt

The !important essentially holds infinite points and always takes precedence.

div>p>.className = 12pts
div>p>#classname = 102pts

This implies that any styles within

div>p>#classname

will take precedence over any styles within

div>p>.classname

I won't delve into how Angular achieves encapsulation with this method, but if you're curious, here's a helpful article -

Answer №3

Check that the encapsulation is not set to ViewEncapsulation.None

@Component({
  selector: "my-component",
  templateUrl: "./my-component.html",
  styleUrls: ["./my-component.scss"],
  encapsulation: ViewEncapsulation.None
}) 

Answer №4

It seems like many of us are experiencing this issue. The ::ng-deep selector is causing problems as it affects all components globally. To solve this, try using :host as a prefix instead. By doing so, the styles will be contained within the same component and not spill over to others. Use :host ::ng-deep in place of ::ng-deep throughout your code.

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Error in the code that I am unable to locate in JavaScript, HTML, and CSS

I need help creating a navbar that displays the active site using HTML and JS code: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content=& ...

Chrome and Firefox browsers are not supporting HTML simple anchor links

Creating a portfolio page at this link (http://198.96.94.51/v2/) and encountering an issue with the navigationMenu. When rapidly clicking on the links on the side, they do not redirect to the correct anchor point (some don't move the page at all). I h ...

Using the last child as a parent element in Selenium with JavaScript

I am trying to access the input element of the last child in this code snippet. Specifically, I want to retrieve the text Text Reply - Delete. <div class="priority-intent-div"> <div class="row add-priority-intent-div"> ...

The v-bind class feature is failing to update the CSS on the object's properties

I'm attempting to dynamically modify the CSS of certain buttons based on object properties within a list. Below is the data I am rendering out, and despite following the documentation and ensuring my setup is correct, I seem to be overlooking somethin ...

"Learn how to showcase a picture in full-screen mode when the webpage is opened

I recently came across a script on Stack Overflow that allows me to select an image at random from an array. The script can be found here: Script to display an image selected at random from an array on page load However, I want to take this concept furthe ...

Emitter fails to emit the value

I've been working on a filter component that looks like this: <app-filter (newStatusValue)="changeListByStatus($status)" However, I'm running into an issue where nothing is being output... changeListByStatus($status){ console.log('ch ...

"Tagging multiple content snippets within a label element to create a truncated text

How can I truncate a specific inner span of a label, containing multiple span elements, to prevent overflow into the next line? To address this issue, I have created a JSFiddle available at https://jsfiddle.net/keltik/k18892xe/3/. Here is a snippet of the ...

Is it possible to replace text on click using CSS instead of jQuery?

My new project involves creating a flashcard system. The idea is that when a question is clicked, it reveals the answer and hides the question. To achieve this, I am currently using the following code: jsFiddle <p id="shown">What is stackoverflow?&l ...

Customize elements such as MuiTab that rely on media queries

Looking to customize the font size for MuiTab using CSS overrides. While following the material-ui documentation for CSS overrides, I successfully adjusted the font size for most elements. However, I encountered an issue with elements that utilize media q ...

Cookies with the HttpOnly attribute are not transmitted in a request

I have implemented the use of HttpOnly cookies in my Java code like this: ... Cookie accessTokenCookie = new Cookie("token", userToken); accessTokenCookie.setHttpOnly(true); accessTokenCookie.setSecure(true); accessTokenCookie.setPath("/"); response.addC ...

What methods can be used in Angular 2 to delete and update row data through HTTP calls?

I am currently working on implementing employee data manipulation functionalities in an Angular application. While I have successfully managed to add new data to the array, I am facing challenges with updating and deleting existing data. Could someone pro ...

The parent component is failing to pass the form values to the child form group in CVA

My Angular application (view source code on Stackblitz) is running Angular 15, and it utilizes reactive forms along with a ControlValueAccessor pattern to construct a parent form containing child form groups. However, I am encountering an issue where the d ...

Angular is having trouble locating the module for my custom library

Trying to implement SSR in my angular application, but encountering an error when running npm run build:ssr. I've created my own library named @asfc/shared, which is bundled in the dist folder. ERROR in projects/asfc-web/src/environments/environment. ...

After upgrading from Angular 7 to 12, the module './rest.service.interface' does not export 'RestService' (imported as 'RestService'), causing it to not be found

Hey everyone, I've been struggling with a problem for hours now and I can't seem to fix it. Here is the interface I'm working with: import { HttpClient } from '@angular/common/http'; import { Response } from '@angular/http&apo ...

Overflowing content in a table within a div element

Issue: I am encountering a problem with resizing a table inside a div that contains input elements. When I adjust the browser window size or change to a lower resolution, the div element resizes and scales down, causing a horizontal scroll bar to appear. H ...

Navigating in Angular - directing a URL to a specific component

I am encountering an issue with redirecting my app in production mode. When I try to access the URL http://server.com/project/dashboard, the server responds with an IIS error page 404. To workaround this, I need to open the app using the URL http://server. ...

Learn how to use CSS flexbox to easily vertically center items within a container with a full-height background

I'm having trouble with aligning text vertically centered within a box and making sure the background color stretches to full height. HTML: <div class="feature-content"> <div class="feature-visual"> <div class="embed-container"> ...

Utilizing a CSS file within a YAML configuration in R Quarto

Is there a way to reference a css file from a yaml file in my R Quarto Book? The css file defines the theme for my Quarto document, and I want all our Quarto docs to have the same appearance. When I directly call the css file, I can customize aspects like ...

Strategies for managing dependent HTTP service call subscriptions with RxJs operators

In my application, I have implemented a function called fetchSeviceProviders that retrieves a list of service providers and allows me to set the logo for each provider by making a separate API call. Currently, I am using two subscriptions to achieve this f ...

Transmit information to Component via Modal Service

I am utilizing a Modal Service in Angular 7. To see an example, check out this StackBlitz Example. The service is used as follows: export class AppComponent { constructor(private modalService: ModalService) { } openModal() { this.modalService.o ...