...JavaScript function that you can use for that: function debounce(callback, delay) { let timer return function(...args) { clearTimeout(timer) timer = setTimeout(() => { callback.apply(this, args) }, delay) } } Usage example function onScroll() { ... } window.addEventListener...

...match a certain criteria or not, Enumerable#partition can come in handy. # Enumerable#partition returns two arrays, # the first containing the elements of enum # for which the block evaluates to...

JavaScript Create an object with no properties with Object.create(null) => {} The comma operator returns its last expression

...call Nokogiri::HTML to be more liberal about accepting invalid XML. xml / 'list item' returns all matching nodes; list item is used like a CSS selector xml / './/list/item' also returns...

...an XPath selector XPath seems to be triggered by a leading . or / xml % 'item' returns the first matching node node.attribute('foo') returns the attribute named foo node.attribute('foo').value returns...

...simply mock time using Timecop.travel or its respective Spreewald steps and the browser will return the same time in new Date(). If you would like to stop the time from...

Ändere die Konfiguration in der ConfigMap (valide Konfiguration). Du kannst beispielsweise mit return einen custom HTTP Statuscode zurückgeben. Wird die Konfiguration jetzt erfolgreich angewendet? Verwende kubectl rollout restart...

...Erstelle eine neue ConfigMap, die den gleichen Inhalt hat wie deine bisherige. Ändere den returncode nochmals auf einen neuen Wert. Editiere das Deployment und lass es die neue ConfigMap verwenden...

...write something similar using jQuery.grep. let classes = Array.from($element.prop('classList')) let existingModifiers = classes.filter(className => { return className.match(/^is-/) }) $layout.removeClass(existingModifiers.join(' ')) Note that classList is native DOM API and returns a DOMTokenList...

...read: forever) you may pass a function that disects an element's class, and returns a string that will then be removed through the "classic" string approach. It's a...

...developer who just wrote it. To check its readability, a good strategy is to return after a few months. You will have forgotten the direct context, but will still be...

...Summary ---------------------------- So, what's the final verdict on those 7 closure-like entities? "return" returns from closure True closure? or declaring context...? Arity check? --------------- ----------------------------- ------------------- 1. block (called with yield) N...

...block (&b => f(&b) => yield) N declaring no 3. block (&b => b.call) Y except return declaring warn on too few 4. Proc.new Y except return declaring warn on too few...

...will not cause problems. However, in some cases it's possible that the data returned by query that has been backed by a corrupted index would differ from a query...

...that has been backed by a correct index. It's possible that queries will return different results or the same results with different sorting after the index has been re...

...and .then() do not behave the same. In particular, if a standard promise callback returns another promise, this will delay the resolution of all later promises. jQuery's then behaves...

...the response, make a second request to /bar: var promise = $.ajax('/foo').done(function() { return $.ajax('/bar'); }); Quiz: When does promise resolve? Well, if you use done, it will resolve...

...into your ~/.config/awesome/rc.lua. It supplies two methods: execute_command will run a command and return its output. Multiple lines will be joined into one line. The code is from the...

...method that takes a command to run and a timeout in seconds. It'll return an object which contains a widget that you can put into your panel. ^

...Our assumption is that the element is considered visible (i.e. Capybara::Selenium::ChromeNode#visible? returns true for such elements) but the Selenium driver wants to actually click the center of...

...achieve this by using a callback. before_initialize :set_newsletter private def set_newsletter return unless [nil, ''].include?(receive_newsletter) self.receive_newsletter = (user.role == 'customer') end Note: When using active_type...

...in mind that their syntax is a bit different. UnderscoreJS In UnderscoreJS, methods always return a value: x = [1, 2, 2] _.uniq(x) // => [1, 2] _(x).uniq() // => [1, 2]

...chain, and call value() to terminate the chain. _.chain(x).uniq().map(function(i) { return i + 10 }).reverse().value() // => [12, 11] LoDash In LoDash, methods called from _ (like _.uniq) will...

var languageString = navigator.language || navigator.userLanguage || ''; var language = languageString.split(/[_-]/)[0]).toLowerCase(); switch (language) { case 'de': return "/de/"; case 'en': return "/en/"; default: return "/en/"; } })(); Note that old IEs support only navigator.userLanguage...

...which returns the regional setting of the operating system. Fallback For users without JavaScript, you may want to redirect them to your default locale. Do that by adding a meta...

...die grundsätzlichen "Bestandteile" von iptables Tables Chains Rules Targets Du verstehst was drop, reject, return und accept machen. Du kennst die 4 default tables Wie kannst du dir iptables Regeln...

...called an “inversion of control”. A function that accepts a callback instead of a return value is saying, “Don’t call me, I’ll call you.”. Promises un-invert the...

...Edge, there are polyfills for Internet Explorer. Usage: Usage Assume this piece of code returns a promise: api.get('pages') // => Promise You may now chain function calls to the promise using...

...jQuery (but before jquery-ujs): whitelisted = (url) -> for domain in ["http://trusted.host/", "https://another.trusted.host/"] return true if url.indexOf(domain) == 0 false $.ajaxPrefilter (options) -> if whitelisted(options.url) options.crossDomain = false

git name-rev --tags Note The more commonly used git describe command will return the last tag before a commit, git name-rev the next tag after the commit...

...message to be set, like this: savon.expects(:action_name).with(message: { user_id: 123 }).returns(' ') If you want to stub only the returned XML and do not care about request...

...you can not omit with as Savon's helper will complain: savon.expects(:action_name).returns(' ') ^ Savon::ExpectationError: Expected a request to the :action_name operation with no message.

The attached download_helpers.rb provides a download_link method for your Capybara tests. It returns a hash describing the download's response: details = download_link('Download report') details[:disposition] # => 'attachment...

foo bar baz Hello Universe without :scope A simple document.body.querySelectorAll('div') will return a NodeList with 5 items, i.e. all 5 divs from above. with :scope Using document.body.querySelectorAll...

...run some_expensive_calculation every time you call var_value if some_expensive_calculation returns nil. This illustrates the problem: def some_expensive_calculation puts "i am off shopping bits...

...shorthand vor "nil or undefined", so if you want to cache something that can return nil, you can not use it. You will have to check for 'defined?' only, ignoring...