Angular 7 SCSS Doesn't Keep CSS Custom Properties - css

I'm trying to use CSS Custom properties in my Angular 7 app but am running into issues where building down to css gets rid of the property that is set to a CSS variable.
SCSS
:root {
--my-test-var: red;
}
.testclass123 {
height: 150px;
background: var(--my-test-var);
}
Builds down to:
:root {
--my-test-var: red;
}
.testclass123 {
height: 150px;
}
If I use a fallback options like var(--my-test-var, purple); then .testclass123 will also have property background: purple;
My Angular version is 7.2.7 and Angular Material 7.3.7

If you use SCSS as global style you can define like this the color.
This is the best approach.
$product: red;
And then only you call when you need like this.
background-color: $product;

Related

How to change the size of the arrow in vue-tour?

I am not able to change the arrow size in vue-tour. While I am able to change it by inspecting in Chrome, in CSS I am unable to do it as it has some runtime generated ID associated with it.
.v-step__arrow[data-v-e97491e4], .v-step__arrow[data-v-e97491e4]:before {
position: absolute;
width: 10px;
height: 10px;
background: inherit;
}
The v-step GitHub is available here: https://github.com/pulsardev/vue-tour/blob/master/src/components/VStep.vue
You can make use of v-deep. It helps in applying the styles to the child-components directly.
If you are making use of sass then you can apply styling as:
::v-deep .v-step {
background-color: black;
}
If you are simply using css then you can use v-deep as:
>>> .v-step {
background-color: black;
}

How is it possible to adjust a component's CSS based on a global CSS class-name in Angular?

We are using a class on the html-element to determine whether the user is in dark or light mode of the app.
<html class="dark-mode"></html>
This class is added using Renderer2 in a service that detects the selected setting of the user. This works fine so far.
Now, we have to adjust all the components to look good in the dark mode as well. But the problem is Angular's ViewEncapsulation.
What we thought would come in handy, is to simply update the SCSS of the component:
.headline {
color: black;
.dark-mode & {
color: white;
}
}
Or in plain CSS:
.headline {
color: black;
}
.dark-mode .headline {
color: white;
}
Now this doesn't work, because the class .dark-mode seems to be encapsulated, as expected.
How can we solve this problem?
:host-context provides access to css classes above the :host. By using :host-context you are able to check if any of the parents of the host have a specific css class and apply styling:
:host-context(.dark-mode) h2 {
color: white;
}
Documentation: https://angular.io/guide/component-styles#host-context

Compile non-root CSS custom property

Are there any tools to compile CSS custom properties declared at not :root rule? I want following code with custom properties
.dark {
--bg-color: black;
--fg-color: white;
}
.light {
--bg-color: white;
--fg-color: black;
}
.foo {
background: var(--bg-color);
display: block;
}
.bar {
color: var(--fg-color);
display: inline;
}
be compiled to their non-custom-prop equivalents like that
.light .foo, .light.foo {
background: white;
}
.dark .foo, .dark.foo {
background: black;
}
.light .bar, .light.bar {
color: black;
}
.dark .bar, .dark.bar {
color: white;
}
.foo {
display: block;
}
.bar {
display: inline;
}
The goal is to
switch color schemes by switching dark/light class on root DOM element
use valid css syntax (no sass less)
keep rules code compact
It's actually not safe to do that. I can tell you because I tried so hard to make a safe transformation.
But I failed.
https://github.com/postcss/postcss-custom-properties/issues/1
Ideal solution. Your example is valid CSS and can be used in many browsers (not in IE, Edge (but is in development) and Opera Mini as of writing this answer, 2017-03-27, other major browsers are fine).
Suboptimal solution. Some CSS can be transpiled to achieve better browser support. The solution I found does not support variables on non-:root elements, however. There are also other objections against transpiling of 'future' CSS into 'current' CSS. To the best of my knowledge, you will have to implement your own transpiler (or postcss plugin) if you want to transpile custom properties not on the :root element, but be warned that that is hard in general. Now you don't need the general part, so it is possible. Just does, to the best of my knowledge, not exist yet.
Preprocessing solution. Of course, you don't need a general implementation of custom properties. You have different themes that have their own values for the same set of properties and that's it. Thus, a separate stylesheet can be created as a preprocessing step using any CSS preprocessor.
Now you say the following,
use valid css syntax (no sass less)
but I am going to show this anyway, because I believe that it is a valid solution to your problem. It is definitely the only one I know that actually works if you want to/need to support IE, Edge and/or older versions of other major browsers (Firefox < 31, Chrome < 49, Safari < 9.1, Opera < 36)
You could do this using SASS for example, to do the transpiling on the server side.
// define styles, use variables throughout them
// your entire style definition goes into this mixin
#mixin myStyles($fg-color, $bg-color) {
.foo {
display: block;
background: $bg-color;
}
.bar {
display: inline;
color: $fg-color;
}
}
// define themes, that set variables for the above styles
// use named arguments for clarity
.dark {
#include myStyles(
$fg-color: white,
$bg-color: black
);
}
.light {
#include myStyles(
$fg-color: black,
$bg-color: white
);
}
This compiles to the following.
.dark .foo {
display: block;
background: black;
}
.dark .bar {
display: inline;
color: white;
}
.light .foo {
display: block;
background: white;
}
.light .bar {
display: inline;
color: black;
}
This is not exactly what you want to obtain, but very close. Realistically, I think this is the closest you will get to obtaining your desired output. I know you want to
keep rules code compact
but what you are saying there (I think) is that you want to split out custom properties from their rules to save on number of rules, which is not something any preprocessor I know supports.
You can organize your source SASS in separate files to keep an overview easily. You can even set up a build system that generates a separate stylesheet for every theme you have. It is then possible to have your users select an alternative stylesheet. Browsers have some support for this, but switching using JavaScript is also definitely possible in the latter case. Simply set all stylesheets to be disabled except for the selected one. Here is an example.

Where to find ZK sclass available items?

I'm using ZK and I want to make use of the ZK sclasses for the items in my .zul files.
I saw that you can use things like :
<style>
div.z-tree {
background: none !important;
background-image: none !important;
border: none !important;
}
div.z-tree-body {
background: none !important;
}
tr.z-treerow-seld, tr.z-treerow-over {
background: #00533f !important;
}
div.z-treecell-cnt {
color: #5555ff;
}
.test-class div.z-treecell-cnt {
color: #ff5555 !important;
}
</style>
Where can I find all those styles, like z-tree-body that I can use and all the attributes I can assign to them or how to search for them?
When I need to override some CSS, I always search the specific CSS classes with the browser developer tools.
Because you want to override the CSS of some nodes but not all, try to use sclass to a specific class of your own.
Example :
<style>
.red {
color:red;
}
<style/>
<label sclass="#load(empty vm.property?''':'red')" />
You don't need to use the zk classes if it's for particularisme cases. For overriding them all, you can beter use the zk classes.

Apply styles to GWT widgets

I have just started to explore GWT, and i'm bit confused with different ways of applying styles to GWT widgets.In gwt docs, there are 4 ways by which you can override default style of a widget,
1) Using a tag in the host HTML page.(Deprecated)
2) Using the element in the module XML file.(Deprecated)
3) Using a CssResource contained within a ClientBundle.
4) Using an inline element in a UiBinder template.
Suppose i have a CSS file in some package say, com.abc.xyz.styles.css .And the file has the following contents,
/**the panel itself**/
.gwt-TabLayoutPanel {
border: none;
margin: 0px;
padding: 0px;
}
/**the tab bar element**/
.gwt-TabLayoutPanel .gwt-TabLayoutPanelTabs {
background-color: #F4F4F4 !important;
}
/**an individual tab**/
.gwt-TabLayoutPanel .gwt-TabLayoutPanelTab {
background-color: #6F6F6E !important;
}
.gwt-TabLayoutPanel .gwt-TabLayoutPanelTab-selected {
background-color: white !important;
}
/**an element nested in each tab (useful for styling)**/
.gwt-TabLayoutPanel .gwt-TabLayoutPanelTabInner {
font-family: Arial !important;
}
/**applied to all child content widgets**/
.gwt-TabLayoutPanel .gwt-TabLayoutPanelContent {
border: none;
margin: 0px;
overflow: hidden;
padding: 15px;
}
How will i inject this css file ? How can this be done using the 3rd and 4th option of styling mentioned above?.
You can simply add your CSS file to the host page. Then you can use the full power of CSS selectors. This is my preferred method of using CSS in GWT:
What the best strategy to structure CSS in GWT?

Resources