I am writhing Angular 2+ unit test with TestBed.
Scenario, I want to verify my component, that the color of a pseudo element.
component.ts
label::before {
right: 0;
background-color: red;
}
#Component({
selector: 'app-test',
template: `
<div><label>a label</label></div>
`,
styleUrls: ['./test.component.scss'],
})
export class TestComponent {
}
so when I write unit test, I want to verify the pseudo element background color
beforeEach(() => {
fixture = TestBed.createComponent(TestComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
it('should set background color', () => {
const ele = fixture.debugElement.query(By.css('label::before')).nativeElement; // error here
// not sure how to use by.css to locate on the pseudo element
expect(ele.backgroundColor).toBe('....');
});
I would suggest writing your test in a different manner.
Fixture is of type ComponentFixture<T> where T is the component you are trying to access. The debugElement property has two properties that you are normally interested In when writing a test componentInstance and nativeElement
ComponentInstance is your component ts file. It's your class declaration in a sense.
NativeElement as the name suggests is the mark-up or your template
I don't think it's possible to do it the way you suggested.
However you could try
const color = window.getComputedStyle(fixture.debugElement.nativeElement.querySelector('label'), ':after').getPropertyValue('background-color');
This will give you a rgb result so for red it would be rgb(255,0,0)
I got this from: How to get pseudo element?
Try this and see if it works. It's not great that we had to access the window element inside of our test but it might solve your issue. Possibly create a better test without having to access the window api i would suggest.
Related
I'm using scoped CSS with https://github.com/gaoxiaoliangz/react-scoped-css and am trying to follow the following rules (besides others):
Scoped component CSS should only include styles that manipulate the "inside" of the component. E.g. manipulating padding, background-color etc. is fine whilst I try to stay away from manipulating stuff like margin, width, flex etc. from within the component CSS
Manipulating the "outside" of a component (margin, width, flex etc.) should only be done by "consuming" or parent components
This is rule is somewhat derived from some of the ideas behind BEM (and probably other CSS methodologies as well) and allows for a rather modular system where components can be used without "touching their outside" but letting the parent decide how their internal layouts etc. works.
Whilst this is all fine in theory, I don't really know how to best manipulate the "outside styles" of a component from the consuming code which is best shown with an example:
search-field.scoped.css (the component)
.input-field {
background: lightcoral;
}
search-field.tsx (the component)
import './search-field.scoped.css';
type SearchFieldProps = {
className: string;
};
export const SearchField = (props: SearchFieldProps) => {
return <input className={`input-field ${props.className}`} placeholder="Search text" />;
};
sidebar.scoped.css (the consumer)
.sidebar-search-field {
margin: 16px;
}
sidebar.tsx (the consumer)
import './sidebar.scoped.css';
// ...
export const Sidebar = () => {
return (
<SearchField className="sidebar-search-field" />
(/* ... */)
);
};
In the above example, the CSS from the class sidebar-search-field in sidebar.scoped.css is not applied because the class passed to SearchField is scoped to the Sidebar and the final selector .sidebar-search-field[data-sidebarhash] simply doesn't match as the input element of the SearchField (obviously) doesn't have the data attribute data-sidebarhash but data-searchfieldhash.
ATM, I tend to create wrapper elements in situations like this which works but is rather cumbersome & clutters the markdown unnecessarily:
// ...
export const Sidebar = () => {
return (
<div className="sidebar-search-field">
<SearchField />
</div>
(/* ... */)
);
};
Question
Is there any way to "style scoped CSS component from the outside"?
Ps.: I'm not sure if all the above also applies to scoped styles in Vue. If not, please let me know how it works there so that I can create a feature request in https://github.com/gaoxiaoliangz/react-scoped-css.
I have a component in React-redux, which has a PagedGrid component (basically a table which renders data row-wise).
<UsersContainer>
<Title>{t('users')}</Title>
<PagedGrid
data-auto-container="user:table"
pageData={user.data}
columns={this.column}
/>
</UsersContainer>
I have created a function for the custom styled component which applies css to the rows of the table inside PagedGrid
const UsersContainer = styled.div`
> table > tbody {
${props => customcss(props)};
}
`;
function customcss({ data = [] }) {
let styles = '';
if (data.length > 0) {
data.forEach((value, index) => {
if (value.mycondition) {
const rowStyle = `& > tr:nth-child(${index + 1}) {
background-color: ${LIGHT_BLUE}
}`;
}
});
}
return css` ${rowStyle} `;
}
Now I want to create a test case using jest to spy on the css of this table and check if the styles are getting applied or not. Can anyone help me on creating a test case for this.
Assuming that you use the #testing-library/react library, you could test your component's style by getting it directly from the html document, and see precisely what style is used for your specific element.
In your example, you can do something like below (assuming that the ${LIGHT_BLUE} value is blue):
import React from 'react';
import { render } from '#testing-library/react';
import UsersContainer from '../UsersContainer';
it('should have the background color set to blue', () => {
const { container, getAllByTestId } = render(
<UsersContainer />
);
// Replace <YOUR_CSS_SELECTOR> by your component's css selector (that can be found in the inspector panel)
let contentDiv = document.querySelector('<YOUR_CSS_SELECTOR>');
let style = window.getComputedStyle(contentDiv[0]);
expect(style.color).toBe('blue');
}
Here, to get the style of your element, I am using the element's CSS Selector. However, it could also work with the element's className, or id directly if it has one, respectively using the methods document.getElementByClassName('YOUR_DIV_CLASS_NAME'), document.getElementId('YOUR_DIV_ID') instead of document.querySelector('<YOUR_CSS_SELECTOR>'). Note that the given name here should be unique, either with the id technique, or the className.
Usually, I can style the very root of my component by using the :host pseudo style like this.
:host{ border: 1px solid gold; }
But how shold I handle if said style is supposed to be set dynamically, based on the parameters passed to #Input?
The only way I can think of at the moment is to add an auxilliary DIV and style it like so.
<div [ngClass]="styleMeDynamically"> ... </div>
Is there a way to apply a style dynamically directly on the host without the injected DIV?
I've found this suggestion but it requires explicitly stating the classes and connecting them to separate inputs. I'd like to get a config object as passed in parameter and bind the styling using [ngClass] to retail full flexibility.
Probably #HostBinding decorator can help you. It allows to bind any host attribute including class and style. For example:
#Component({ ... })
export class MyComponent {
// you can conditionally add a class to the host element
#Input()
#HostBinding('class.large')
large = false;
// it's possible to bind a style as well
#Input()
#HostBinding('style.border.px')
borderWidth = 1;
#Input()
green = false;
// and you can use a getter
#HostBinding('style.border-color')
get borderColorStyle() {
return this.green ? 'green' : 'black';
}
}
Since angular 9 it should be possible even to bind a CSS variable, see Improved CSS class and style binding section of the 9 version release article.
<div [style.--main-border-color]=" '#CCC' ">
<p style="border: 1px solid var(--main-border-color)">hi</p>
</div>
What you can do is,
Create a custom directive that will accept a style object. and inside that directive, you can get the reference of host element and modify its style.
Here is a Demo
And here is a quick explanation.
Create a directive as which will accept a style object.
import {Directive,TemplateRef,ElementRef,OnChanges,SimpleChanges,OnInit,Renderer2,DoCheck,Input} from "#angular/core";
#Directive({
selector: "[appSetStyle]"
})
export class SetStyleDirective implements OnInit, OnChanges {
#Input() appSetStyle: { [key: string]: any } = {};
constructor(private elementRef: ElementRef<HTMLElement>) {}
ngOnInit(): void {}
ngOnChanges(changes: SimpleChanges): void {
this.applyStyles();
}
applyStyles(): void {
if (this.appSetStyle) {
for (const key in this.appSetStyle) {
this.elementRef.nativeElement.style[key] = this.appSetStyle[key];
}
}
}
}
Use that style object with any html element or any other component in your project.
<app-header [appSetStyle]="dynamicStyles"></app-header>
If you don't want to make a directive then you can inject the ElementRef inside the component itself which you want to style.
ElementRef is the what you need to use to get the reference of host.
I hope this will help.
The title is not really a question it is more like an idea, I don't know what approach is best for my situation.
So, the problem. I have some 3rd party component that have some complex structure and styling. Some part of it has some predefined CSS class that I can override with CSS in my surrounding component. Something like this:
my component:
<div class="my-cmp-container">
<some-3rd-party-cmp></some-3rd-party-cmp>
</div>
3rd party component:
<div class="3rd-party-css-class">
...
</div>
For example, 3rd-party-css-class has style background-color: #f00, I can override it with .my-cmp-container .3rd-party-css-class { background-color: #fff; } etc. But. What if I need to set color dynamically, it's stored in a DB for example and I can't predefine each case in my class' CSS. I just have the color in hex.
In theory I can generate unique string to set as CSS class for every instance of some-3rd-party-cmp and somehow generate CSS in my component? I'm lost a little, what is the best approach for this?
Edit: Code sample to illustrate the situation https://stackblitz.com/edit/angular-kxdatq
What you are trying to do is the subject of this open issue about stylesheet binding in Angular. Until that feature is available, you can get what you want with a custom directive. Here is a directive that retrieves the checkbox element generated by ng-zorro-antd and applies two color attributes to it. The two colors are #Input properties and the directive implements OnChanges which allows to react to property binding changes.
#Directive({
selector: "[nz-checkbox][nz-chk-style]"
})
export class CheckBoxStyleDirective implements OnInit, OnChanges {
#Input("nz-chk-bkgnd") chkBkgndColor: string;
#Input("nz-chk-border") chkBorderColor: string;
private checkbox: HTMLElement;
constructor(private renderer: Renderer2, private el: ElementRef) { }
ngOnInit() {
this.checkbox = this.el.nativeElement.querySelector(".ant-checkbox-inner");
this.updateBackgroundColor();
this.updateBorderColor();
}
ngOnChanges(changes: SimpleChanges) {
if (changes.chkBkgndColor) {
this.updateBackgroundColor();
}
if (changes.chkBorderColor) {
this.updateBorderColor();
}
}
updateBackgroundColor() {
if (this.checkbox) {
this.renderer.setStyle(this.checkbox, "background-color", this.chkBkgndColor);
}
}
updateBorderColor() {
if (this.checkbox) {
this.renderer.setStyle(this.checkbox, "border-color", this.chkBorderColor);
}
}
}
Once the directive attribute selector nz-chk-style is applied to the 3rd party element, you can set the checkbox background and border colors with property binding as follows:
<span nz-checkbox nz-chk-style [nz-chk-bkgnd]="bkgndColor" [nz-chk-border]="borderColor" >
See this interactive stackblitz for a demo.
Not sure if you are using Angular but you tagged it, so I guess you are.
If you want to change only the color and nothing more, instead of having a .3rd-party-css-class class, you could just have your with an ng-style like so:
<some-3rd-party-cmp ng-style="{ color: your_color_hex_variable }"></some-3rd-party-cmp>
You can also define a whole object if styles and pass it.
You can also use ng-class and pass one or an array of class names what you want to put additionally on your component:
<some-3rd-party-cmp ng-class="[cls1, cls2, cls3]"></some-3rd-party-cmp>
<some-3rd-party-cmp ng-class="[3rd-party-css-class, someCondition ? 'another-class-name' : '']"></some-3rd-party-cmp>
In the classes you can define the css rules you want to apply and thats it.
With this solutions you can avoid having extra wrapper elements for styling purposes which is a nice thing.
I am trying to highlight a row based user input. I am using Angular 5, with ag-grid-angular 19.1.2. Setting the style with gridOptions.getRowStyle changes the background, but I would rather use scss classes if possible. The function setHighlight() is called in the html file through (change)=setHighlight()
setHighlight() {
const nextChronoId = this.getNextChronoDateId();
// this.highlightWithStyle(nextChronoId); // Working solution
this.highlightWithClass(nextChronoId);
const row = this.gridApi.getDisplayedRowAtIndex(nextChronoId);
this.gridApi.redrawRows({ rowNodes: [row]})
}
Function definitions:
highlightWithStyle(id: number) {
this.gridApi.gridCore.gridOptions.getRowStyle = function(params) {
if (params.data.Id === id) {
return { background: 'green' }
}
}
}
highlightWithClass(id: number) {
this.gridApi.gridCore.gridOptions.getRowClass = function(params) {
if (params.data.Id === id) {
return 'highlighted'
}
}
}
My scss class:
/deep/ .ag-theme-balham .ag-row .ag-row-no-focus .ag-row-even .ag-row-level0 .ag-row-last, .highlighted{
background-color: green;
}
My issue
Using getRowClass does not apply my highlighted class correctly to the rowNode. After reading (and trying) this, I think that my custom scss class overwritten by the ag-classes. The same problem occurs when using rowClassRules.
Question
How can I make Angular 5 and ag-grid work together in setting my custom scss class correctly?
Stepping with the debugger shows the class is picked up and appended to the native ag-grid classes.
In rowComp.js:
Addition, screen dump from dev tools:
angular's ViewEncapsulationis the culprit here.
First be aware that all shadow piercing selectors like /deep/ or ::ng-deep are or will be deprecated.
this leaves, to my knowledge, two options.
use ViewEncapsulation.None
add your highlighted class to the global stylesheet
setting ViewEncapsulation.None brings its own possible problems:
All components styles would become globally available styles.
I would advise to go with option two.
this answers sums it up pretty well.
Additionally:
.ag-theme-balham .ag-row .ag-row-no-focus .ag-row-even .ag-row-level0 .ag-row-last
this selector will never match anything, you should change it to
.ag-theme-balham .ag-row.ag-row-no-focus.ag-row-even.ag-row-level0.ag-row-last
every class after ag-theme-balham exists on the same element.
with the selector you wrote, you would denote a hierarchy.
Hope this helps