Bind Angular 2 variable to css pseudo-class content: attr() expression - css

I wanted to compare performance of rendering Angular 2 variable binding [innerText]/{{}} with binding variable as content of pseudo-class(because methods above forces element re rendering)
However, I struggle trying to make angular markup work with css.
That works
CSS:
.my-el:after {
content: attr(my-attr);
}
HTML
<div class="my-el" my-attr="text"></div>
But after change it to my-attr="{{myVar}}" Angular throws error:
browser_adapter.js:77 EXCEPTION: Template parse errors(...)
So I red that I should use attr.my-attr="{{myVar}}"
But after changing CSS to
.my-el:after {
content: attr(attr.my-attr);
}
it doesn't work (I guess dot isn't valid symbol here?).
I know that all above may have not much sense, however I'm finding it as interesting problem which I can't solve so far.
Any ideas how to make these two work together? Thanks in advance!

You will have to bind your value with the following way
<div class="my-el" [attr.my-attr]="myVar"></div>
This way angular will attach the myVar contents to the my-attr attribute
If you need to prepend it with data- use
<div class="my-el" [attr.data-my-attr]="myVar"></div>
Then you can access the value from your css with
attr(my-attr) or attr(data-my-attr)

Related

How do I add the same CSS property (e.g. background-image) multiple times with React?

I want to do the equivalent of style="background-image: url(foo.jpg); background-image: -webkit-image-set(url(foo_1x.jpg) 1x, url(foo_2x.jpg) 2x)" in a React component.
React requires me to provide a style object, not a string. But a JS object can't have the same property twice.
How do I get two background-image properties? Also, the order is significant – the image-set needs to be last.
It needs to be an inline style. (Because the URL is a dynamic, interpolated value retrieved from DB.)
I think I initially misunderstood your question. Seems you are looking to create a style object to pass as a prop to a component. You can combine your background images into a single comma separated list. You can use a string template to inject the dynamic image urls at runtime.
const style = {
backgroundImage: `url(${url1}),-webkit-image-set(url(${url2}) 1x, url(${url3}) 2x)`,
};
"spassvogel" on GitHub has a clever solution using CSS variables: https://github.com/facebook/react/issues/20757#issuecomment-776191029
The idea is to set CSS variables in the style property, like
style={ "--url1": "url(1.jpg)", "--url2": "url(2.jpg)" }
and then using them from an external style sheet, like
background-image: var(--url1);
and so on.
Turns out this still wasn't enough to solve everything I wanted – this rabbit hole runs ever deeper – but that's no fault of React's, so I'll consider this a valid answer.

How can I use colours stored in JSON in my CSS?

I need to get some colour values out of a DB and use them in my CSS so that each customer has a colour branded version of my React.js application, but I'm not sure how.
I have other elements of branding such as logos, slogans and terminology which I'm pulling out of the DB, storing as a JSON file, and referencing around the site, which works fine, but the problem is the colours which I need to use in my stylesheet as I need to use the pseudo classes that CSS offer.
I've found this postcss-import-json package which claims to do this, but I can't seem to get it to work as intended.
So far I've...
Imported the package...
npm install --save-dev postcss-import-json
Created a JSON file called 'masterConfig.json'
Imported the above file into my main stylesheet using the name i've called my colour (primary)...
:root { #import-json "../Assets/MasterConfig/masterConfig.json" (primary); }
Added the above colour name to my list of colours...
:root {primary: primary}
I've also tried this with the -- prefix by changing to #import-json... (primary as primary prefix --)
...and added it in my code where it is to be used...
style={{background: "var(--primary)"}}
^^^ with and without the prefix
Am I doing something wrong?
I've noticed in the example it uses the $ symbol, so can this only be used with SCSS?
Any help with this, or any other way to achieve this would be great, thanks!
So, I was quite surprised that I didn't already know how to do this, it seems so trivial and doesn't need any additional package.
To change a CSS varibale from JavaScript code, simply target the root element as you normally would, and set the property!
CSS
Create a variable (I'm using a fallback colour)
:root {--primary: #123456;}
JavaScript
I'm using React, and set this is my App.js componentDidMount function so it's global to my app. I've hard-coded the colour, but this can be pulled from the DB.
componentDidMount() {
const root = document.documentElement;
root.style.setProperty('--primary', '#CCCC00');
}
BooYaa!
There appears to be two was to access the variable you've defined, I've done it in two separate ways and you can implement whichever makes your code neater!
Referencing the variable inline:
CSS
:root {
--testcolor: red;
}
HTML
<div style="background:var(--testcolor)">
Many words
</div>
Example of the working product in JS Fiddle: https://jsfiddle.net/ta37nzer/
Accessing the variable through a class:
CSS
:root {
--testcolor: red;
}
.exampleClass {
background: var(--testcolor);
}
HTML
<div class="exampleClass">
Many words
</div>
Example of the working product in JS Fiddle: https://jsfiddle.net/ta37nzer/1/

Smart gwt hint in field styling

My code:
myTextItem = new TextItem();
myTextItem.setHint("Some text");
myTextItem.setShowHintInField(true);
myTextItem.setHintStyle("myTextItemHint");
My css:
.myTextItemHint {
color: gray;
}
My Problem:
My issue is that I can have that setShowHintInField(true) set OR my css getting applied, but not both.
I found more info about this on the link: http://forums.smartclient.com/showthread.php?t=14463 but I cannot come up with a common style / place for it, that would make the trick while the hint is inside the field.
My question:
What kind of css would I need in this case and how I tell the field to use it?
What I have tried:
With that setShowHintInField(true) line and without. Both cases: half of the solution is there. Not both halves.
FormItem has method setCellStyle() to set the style of specific cell.
Use
myTextItem.setCellStyle("myTextItemHint");
your CSS will look like this:
.myTextItemHint, .myTextItemHint input {
color: gray;
}
Override other properties also if needed
.textItem,.textItemFocused,.textItemDisabled,.textItemDisabledHint,.textItemError,.textItemHint
For more information on CSS, Please have a look at skin_styles.css that is already shipped along with standard skins in SmartGWT.

Using less.css and Twitter Bootstrap 3 - mixins not working

Alrighty, so I am trying to add classes to my page via css. Below is an example of the less.css file I am writing:
.someClass {
.col-sm-6;
}
I swear this worked before, but for whatever reason, my compiler throws an error:
".col-sm-6 is undefined"
Compiler: WinLess
Essentially I'm just trying to assign the col-sm-6 class to a div for width/float etc... Please let me know if you can think of any reasons this wouldn't work.
Thanks!
Bootstrap 3 makes these class names via a dynamic mixin, so they are not directly accessible as mixins themselves (dynamically generated class names are not currently able in LESS to be accessed as mixins). Instead, you need to call the mixin to generate the code by doing this:
.someClass {
.make-sm-column(6);
}

Style row banding and selection in tr:table using CSS

I've got a tr:table that I need to style using CSS. All the normal style functions of a table are working, but row banding and row selection aren't coming up. When I view the rendered source, I'm not seeing a difference in the rows for an id or class to grab on to, and the official documentation doesn't have any attributes for declaring a style class for either. Is this possible and if so what do I need to do to get my CSS to grab onto it?
<tr:table id="myTable" value="#{tableValues}" rowBandingInterval="1">
<tr:column>
##Stuff##
</tr:column>
<tr:column>
##Stuff##
</tr:column>
<tr:column>
##Stuff##
</tr:column>
</tr:table>
Edit
Let me try to clairfy what's happening.
First, using the declaration above tells jsf to generate a table, and the attribute rowBandingInterval tells it to give each row alternating colors (If it was set to 2, then it would do 2 rows one color, 2 rows another, 2 rows the original, etc.)
Once the page gets rendered into standard html, trinidad (and jsf) apply their own classes and IDs to the html. My normal procedure is to look at the rendered html, find the class that it is appling and add CSS rules for it. However in this case, no additional styles are added (nothing in the rendered html denotes one row to be different from another).
So the question is, how do I tell trinidad to either give alternating rows and the user selected row different classes/IDs for me to grab on to with CSS?
Edit 2
Just to keep anybody paying attention posted, there are no changes to the actual td elements either
Edit 3
After having switched all the attributes around and then stripping all the code down to it's bare bones, I found the row banding attribute. Trinidad classes are rather convluted, and unless you reformat the code and pull out all the noise you won't see it. Trinidad adds the class .af_column_cell-text-band to the banded rows, where as the normal rows have just .af_column_cell-text. So that's half the problem solved. I still need to know the selector for a user selected row, for which I'll happily give all the marbles to anybody that can give me an answer to just that.
This is not directly answering your question, but why not use the CSS3 pseudo-class nth-child to achieve this effect ? For instance :
tr:nth-child(2n)
{
background-color:red;
}
There is a nice and simple jquery code to do the row highlighting located here.
The jQuery is as follows
<script type="text/javascript">
$(document).ready(function(){
$(".stripeMe tr")
.mouseover(function() { $(this).addClass("over");})
.mouseout(function() { $(this).removeClass("over");
});
$(".stripeMe tr:even").addClass("alt");
});
</script>
Then a bit of css
tr.alt td { background: #ecf6fc; }
tr.over td { background: #bcd4ec; }
btw I took all that code from the following site where you can also view the demo.
I made something wrong during the registration process, so this is a new answer instead of a comment.
To deal with the trinidad-skinning topic you need to do the following:
In your web.xml you need to set this parameter to true while developping:
<context-param>
<param-name>org.apache.myfaces.trinidad.DISABLE_CONTENT_COMPRESSION</param-name>
<param-value>true</param-value></context-param>
Get firebug for your firefox. With that add-on you can determine which trinidad-selector is used on a component.
There is no selector for a user selected row. I did it this way:
Give your object something like a "highlight property", which you change if it is the selected one.
<tr:column sortProperty="nr" sortable="true" defaultSortOrder="ascending" headerText="Nr" inlineStyle="#{object.tablerowhighlight}text-align:right;"><tr:outputText value="#{object.nr}"/></tr:column>
Do that for all columns of your table and you are done.
put these selectors in your trinidadskin.css-file(smSkin.css in my case):
.AFTableCellDataBackgroundColor:alias
{
background-color: #F5F5DC;
}
.AFTableCellDataBandedBackgroundColor:alias
{
background-color: #FFFFFF;
}
Configuration of trinidad-skins.xml
<skin>
<id>
sm.desktop
</id>
<family>
sm
</family>
<render-kit-id>
org.apache.myfaces.trinidad.desktop
</render-kit-id>
<style-sheet-name>
skins/sm/smSkin.css
</style-sheet-name>
</skin>
I will refer you to the trinidad documentation.
http://myfaces.apache.org/trinidad/trinidad-api/tagdoc/tr_table.html
In their example they declare the banding as row banding="row" I would assume the reason you do not get anything is that you have not declared if it is row or column banding.

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