How to render checked checkboxes using CSS alone? - css

This is may be very noobish and a bit embarrassing but I am struggling to figure out how to make checkboxes 'checked' using CSS?
The case is that if a parent has a class setup (for example) I'd like to have all the checkboxes having setup as parent to be checked. I'm guessing this is not doable in pure CSS, correct? I don't mind using JS but am just very curious if I could toggle the state of the checkboxes along with that of their parent (by toggling the class).
Here's a fiddle to play around with.

A checkbox being "checked" is not a style. It's a state. CSS cannot control states. You can fake something by using background images of check marks and lists and what not, but that's not really what you're talking about.
The only way to change the state of a checkbox is serverside in the HTML or with Javascript.
EDIT
Here's a fiddle of that pseduo code. The things is, it's rather pointless.
It means you need to adding a CSS class to an element on the server that you want to jQuery to "check". If you're doing that, you might as well add the actually element attribute while you're at it.
http://jsfiddle.net/HnEgT/
So, it makes me wonder if I'm just miss-understanding what you're talking about. I'm starting to think that there's a client side script changing states and you're looking to monitor for that?
EDIT 2
Upon some reflection of the comments and some quick digging, if you want a JavaScript solution to checking a checkbox if there's some other JavaScript plugin that might change the an attribute value (something that doesn't have an event trigger), the only solution would be to do a simple "timeout" loop that continuously checks a group of elements for a given class and updates them.
All you'd have to do then is set how often you want this timeout to fire. In a sense, it's a form of "long polling" but without actually going out to the server for data updates. It's all client side. Which, I suppose, is what "timeout" is called. =P
Here's a tutorial I found on the subject:
http://darcyclarke.me/development/detect-attribute-changes-with-jquery/
I'll see if I can whip up a jQuery sample.
UPDATE
Here's a jsfiddle of a timeout listener to check for CSS classes being added to a checkbox and setting their state to "checked".
http://jsfiddle.net/HnEgT/5/
I added a second function to randomly add a "checked" class to a checkbox ever couple of seconds.
I hope that helps!

Not possible in pure css.
However, you could have a jQuery event which is attached to all elements of a class, thereby triggering the check or uncheck based on class assignments.
Perhaps like this:
function toggleCheck(className){
$("."+className).each( function() {
$(this).toggleClass("checkedOn");
});
$(".checkedOn").each( function() {
$(this).checked = "checked";
});
}

Related

Meteor reactivity with helpers

Debugging an app & I stumbled upon something I never noticed before. For a quick example, I've got a simple link with 2 helpers to style it, like this:
<a class="{{tabHasError}} {{activeTab}}">Test</a>
The helpers that go into this are as follows:
tabHasError: function() {
console.log('invalidated!');
}
activeTab: function() {
if (Session.equals('activeTab', this.tabIdx)) return 'active';
}
Now, every time the Session var changes, activeTab gets invalidated, which is expected. What's not expected is that tabHasError is also invalidated. Why does this happen? Is this normal? Is it because they're both attached to the same element? Aside from merging the functions, any way to avoid this? Or even better, why did MDG make this design decision?
With iron-router, it's normal to observe the behavior you're describing.
The current template in use will be refresh as soon as there is a change into the main computation dependencies. Calling Session.set will call the refresh of the template variable. For sure, it's a lot, but it is one of the simplest way to be sure the template is always up-to-date.
If you're looking for larger app, you could have a look on React.js integration, which will give you the ability to refresh only the good variable on your template.
In fact, in your example, the value of tabHasError should not change, but the re-rendering of the template will called the function tabHasError to check if there is any change. In this case, no.
I'm around if the behavior isn't clear enough. Have a tremendous Sunday!
I noticed that this only happens in an element's attributes. I think this behaviour is very specify, according to Event Minded videos regarding the previous UI engine (Shark): it only rerenders affected DOM elements.
Having in consideration that in your code Blaze is rerendering the DOM element, it makes sense to invalidate previous computations related to it. If you place this helper inside the a element it won't be invalidated.

Detecting for -webkit-apperance with Modernizr

Can anyone tell me how to detect -webkit-appearance, moz-apperance, or appearance using Modernizr?
I have custom selects, and checkboxes that use these and I need to ensure the additional styles are not applied on those browser that dont support these properties.
Thanks
Just use Modernizr.testProp() method:
Modernizr.testProp('webkitAppearance');
And with this check you can write your own Modernizr test using Modernizr.addTest():
Modernizr.addTest('webkit-appearance', function() {
return Modernizr.testProp('webkitAppearance');
});
I'm pretty certain that Modernizr doesn't include a detection routine for this feature yet -- it's just too new.
However, as it's a CSS property, you should be able to detect it fairly simply for yourself without needing to invoke modernizr.
This page details how to do a quick check to detect if a CSS property is available.
Simply check whether the property exists in the style property of any given DOM element. If the property is supported, it will be in the DOM, even if it isn't actually set to anything.
Hope that helps.

How to find all dialogs in JQuery

I am trying to bind an event to all dialogs that have been created on a page using the JQuery UI Dialog function (whether they have been displayed or not). I can't seem to figure out a selector that will get me there. I've tried both .ui-dialog and .ui-dialog-content without success.
Since I'm trying to make a generic method, I won't know the IDs of the dialogs that may have been created.
I'm using the following code to test. It works if I specify a dialog's id (#mydialog), but in production, I won't know these.
$("div.ui-dialog").bind("dialogclose", function(event, ui) {
window.alert("close fired");
}
Do your dialogs have a common class that you can select them with? If they all have the "ui-dialog" class then this will work:
$(".ui-dialog")
Your example of
$("div.ui-dialog")
Is asking to select all divs with a class of ui-dialog, which should probably also work as long as the class is given to a div element.
Your problem might be that you binding the dialog elements before they exist? You might want the .live() function instead so that it binds to any dialogs created at any point and not just the ones that exist when the function is called.
Posting an HTML snippet would help.
You can use this:
$(":ui-dialog").each(function(){
"enter your code here"
})

UpdatePanel - Any ideas on how to avoid a flicker in UI? - ASP.NET/Jquery

I have rather a complex UI. However, for the purpose of this question, let's say that there is a HTML table that renders UILayout1 by default (say default mode). There is a button that a user can use to toggle between the default mode and a preview mode (UILayout2)
When in preview mode, there are some columns in the table that are invisible and there are reordering of rows. I am using JS (jquery) on load to check the mode and change it accordingly.
The table and the toggle button are in UpdatePanels.
Functionally, everything works as expected. However, when a user toggles between default and preview mode or vice versa, there is this short time interval in which the the table renders in default and then JS runs to make changes.
This results in degraded UI experience. Are there any creative ways to avoid this "flicker"?
you can use DIVs or don't use update panel in your UI generation use any concept else
The problem is likely to be that your code is running on load. I'm assuming that you're doing this using the standard jQuery method of running code on load, and not using the window's onload event. In any case, even using jQuerys $(document).ready(...) will be too slow if you have a lot of other javascript files to load, as the .ready event isn't fired on the document until all javascript includes have loaded.
You should be able to work around the issue by including your code that modifies the table just after the html for the table in your page and not running it on load i.e. make sure you don't wrap it in $(document).ready(...);
For this approach to work, you will need to have all javascript required by the code which is modifying the table included earlier in the page.
If you have other non-essential javascript files included, you should try to include them later in the page.
I'm not 100% sure how being inside an update panel will affect it - you will need to make sure that your code is being re-triggered when the updatepanel updates, but I believe this should all happen automatically.
Presumably your UI is controlled by CSS? You might be able to get rid of the flickering by adding something like this at the start of your JavaScript or in the <head> of your HTML:
if (previewMode) {
document.documentElement.className = 'preview';
}
Then if you modify your CSS rules that apply to your preview mode to reflect the HTML element having the class="preview" to something like:
.preview table .defaultMode {
display:none;
}
hopefully your table should render correctly first time and will not need to be re-drawn.

How to prevent a hyperlink from linking

Is it possible to prevent an asp.net Hyperlink control from linking, i.e. so that it appears as a label, without actually having to replace the control with a label? Maybe using CSS or setting an attribute?
I know that marking it as disabled works but then it gets displayed differently (greyed out).
To clarify my point, I have a list of user names at the top of my page which are built dynamically using a user control. Most of the time these names are linkable to an email page. However if the user has been disabled the name is displayed in grey but currently still links to the email page. I want these disabled users to not link.
I know that really I should be replacing them with a label but this does not seem quite as elegant as just removing the linking ability usings CSS say (if thats possible). They are already displayed in a different colour so its obvious that they are disabled users. I just need to switch off the link.
This sounds like a job for JQuery. Just give a specific class name to all of the HyperLink controls that you want the URLs removed and then apply the following JQuery snippet to the bottom of your page:
$(document).ready(function() {
$('a.NoLink').removeAttr('href')
});
All of the HyperLink controls with the class name "NoLink" will automatically have all of their URLs removed and the link will appear to be nothing more than text.
A single line of JQuery can solve your problem.
I'm curious on what it is you which to accomplish with that. Why use a link at all?
Is it just for the formatting? In that case, just use a <span> in HTML and use stylesheets to make the format match the links.
Or you use the link and attach an onClick-Event where you "return false;" which will make the browser not do the navigation - if JS is enabled.
But: Isn't that terribly confusing for your users? Why create something that looks like a link but does nothing?
Can you provide more details? I have this feeling that you are trying to solve a bigger problem which has a way better solution than to cripple a link :-)
A Hyperlink control will render as a "a" "/a" tag no matter what settings you do. You can customize a CSS class to make the link look like a normal label.
Alternatively you can build a custom control that inherits from System.Web.UI.WebControls.HyperLink, and override the Render method
protected override void Render(HtmlTextWriter writer)
{
if (Enabled)
base.Render(writer);
else
{
writer.RenderBeginTag(HtmlTextWriterTag.Span);
writer.Write(Text);
writer.RenderEndTag(HtmlTextWriterTag.Span);
}
}
}
Could be a bit overkill, but it will work for your requirements.
Plus I find is usefull to have a base asp:CustomHyperlink asp:CustomButton classes in my project files. Makes it easier to define custom behaviour throughout the project.
If you merely want to modify the appearance of the link so as not to look like a link, you can set the CSS for your "a" tags to not have underlines:
a: link, visited, hover, active {
text-decoration: none;
}
Though I would advise against including "hover" here because there will be no other way to know that it's a link.
Anyway I agree with #pilif here, this looks like a usability disaster waiting to happen.
If you mean to stop the link from activating, the usual way is to link to "javascript:void(0);", i.e.:
foo
This should work:
onclick="return false;"
if not, you could change href to "#" also. Making it appear as a rest of text is css, e.g. displaying arrow instead of hand is:
a.dummy {
cursor:default;
}
Thanks for all the input, it looks like the short answer is 'No you can't (well not nicely anyway)', so I'll have to do it the hard way and add the conditional code.
If you are using databind in asp.net handle the databinding event and just don't set the NavigateUrl if that users is disabled.
Have you tried just not setting the NavigateUrl property? If this isn't set, it may just render as a span.
.fusion-link-wrapper { pointer-events: none; }
Another solution is apply this class on your hyperlink.
.avoid-clicks {
pointer-events: none;
}
CSS solution to make tags with no href (which is what asp:HyperLink will produce if NavigateURL is bound to null/empty string) visually indistinguishable from the surrounding text:
a:not([href]), a:not([href]):hover, a:not([href]):active, a:not([href]):visited {
text-decoration: inherit !important;
color: inherit !important;
cursor: inherit !important;
}
Unfortunately, this won't tell screen readers not to read it out as a link - though without an href, it's not clickable, so I'm hoping it already won't be identified as such. I haven't had the chance to test it though.
(If you also want to do the same to links with href="", as well as those missing an href, you would need to add pointer-events:none as well, since otherwise an empty href will reload the page. This definitely leaves screen readers still treating it as a link, though.)
In the OP's use case, if you still have the href being populated from the database but have a boolean value that indicates whether the link should be a 'real' link or not, you should use that to disable the link, and add a:disabled to the selector list above. Then disabled links will also look like plain text rather than a greyed-out link. (Disabling the link will also provide that information to screen readers, so that's better than just using pointer-events: none and a class.)
A note of caution - if you add these sorts of rules globally rather than for a specific page, remember to watch out for cases where an tag has no (valid) href, but you are providing a click handler - you still need those to look/act like links.

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