Show or hide a jQuery element given a condition
If you have jQuery code like this:
if (condition) {
$element.show();
} else {
$element.hide();
}
... you can shorten this to:
$element.toggle(condition);
Related cards:
jQuery: How to remove classes from elements using a regular expression
jQuery's removeClass removes the given class string from an element collection. If you want to remove multiple/unknown classes matching a given pattern, you can do that.
For example, consider a DOM node for the following HTML. We'll reference i...
How to show jQuery event handler on element
Chrome gives you the currently selected element in the inspector with $0. If you select a button in the DOM you can set and inspect the event handler with the following two code lines:
$($0).on('click', function() { console.log('H...
Scroll a textarea to a given position with jQuery
Browsers make this very hard. Even when you explicitely set the selection inside the textarea (e. g. using jquery-fieldselection) the browser will not scroll the textarea to this selection.
Wh...
Capybara: Find the innermost DOM element that contains a given string
Let's say you want to find the element with the text hello in the following DOM tree:
<html>
<body>
<article>
<strong>hello</strong>
<strong>world</strong>
</article>
</body>
</html>
You might think of XPath...
Scroll a textarea to a given line with jQuery
You can use this code:
function scrollToLine($textarea, lineNumber) {
var lineHeight = parseInt($textarea.css('line-height'));
$textarea.scrollTop(lineNumber * lineHeight);
}
Some caveats about this code:
- Your t...
jQuery: Find a selector in both descendants and the element itself
jQuery's find looks in the element's descendants. It will never return the current element itself, even if the element matches the given selector.
Require the attached file and you can now say:
$('.container...
Handy: A regex that validates all valid email addresses (give or take) - Axon Flux // A Ruby on Rails Blog
/^([\w!#$%&'*+-/=?^`{|}~]+.)*[\w!#$%&'*+-/=?^`{|}~]+@((((([a-z0-9]{1}[a-z0-9-]{0,62}[a-z0-9]{1})|[a-z]).)+[a-z]{2,6})|(\d{1,3}.){3}\d{1,3}(:\d{1,5})?)$/i
whenever: Installing cron jobs only for a given Rails environment or Capistrano stage
We use the whenever gem to automatically update the crontab of the servers we deploy to. By default, whenever will update all servers with a matching role ([we use the :cron role ](https://makandracards.com/m...
Consul: Dynamically access and query powers for a given name, model class or record
Consul 0.6.1+ gives you a way to dynamically access and query powers for a given name, model class or record.
A common use case for this are generic helper methods, e.g. a method to display an "edit" link for ...
Ruby: How to grow or shrink an array to a given size
If you want to grow a Ruby Array, you might find out about #fill but it is not really what you are looking for. [1]
For arrays of unknown size that you want to grow or shrink to a fixed size, you need to define something yourself. Like the follo...