...that RequestStore just uses Thread.current under the hood and injects a Rack middleware that calls RequestStore.clear! after each request. If you use RequestStore in a non-request context where (like...
...archived => false) authors = posts.traverse_association(:author) You can traverse multiple associations in a single call. E.g. to turn a relation of posts into a relation of all posts of their...
...well as to query the record for registered errors. This object is returned when calling .errors: errors = @user.errors # => # Here are some helpful messages of its API: [ ] Returns an array of...
...Will retrieve the error message from the locale files. get( ) (Almost) an alias of []. Calls messages[ ] and returns an array of error messages for that attribute. include?( ) Returns whether there...
...to express "Do this, and once you're done, do that". In contrast to callbacks, promises are easily chainable. From the readme of Q, an early implementer of the pattern...
...The callback approach is 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...
...that table object will have the cryptic type Cucumber::Ast::Table. Don't immediately call table.raw to convert it into an array of arrays! Cucumber::Ast::Table has a lot...
Browsers blocks abusable JavaScript API calls until the user has interacted with the document. Examples would be opening new tab or start playing video or audio. E.g. if you attempt...
...to call video.play() in a test, the call will reject with a message like this: NotAllowedError: play() failed because the user didn't interact with the document first. https://goo.gl...
...s encrypted password hash, salt and KMS key ID from the database. Make a call to KMS to decrypt the hash (KMS internally stores the corresponding private key but never...
...get exposed either. The only way to decrypt something is to make an API call to KMS. Thus, the only valid attack really is if the attacker is able to...
...let the page jump to the top when the link is clicked, unless you call preventDefault on the event. This is probably not what you want. Do something with js...
JavaScript objects can have getter and setter functions that are called when a property is read from or written to. For example, if you'd like an object that has...
...Performance considerations Read and write accesses have the same performance characteristics of regular function calls, so it's slower than a dumb property...
...the array of methods. @user.methods.grep /name/ # => [:name, :first_name, :last_name] You can also call #private_methods or #public_methods. To find only relevant methods, it is suggested to subtract...
...by native event listeners: let $element = $('.foo') $element.on('change', event => console.log('I will be called')) $element[0].addEventListener('change', event => console.log("I WON'T be called")) $element.trigger('change')
...event listeners (Element#addEventListener()): let $element = $('.foo') $element.on('change', event => console.log('I will be called')) $element[0].addEventListener('change', event => console.log('I will also be called')) let event = new CustomEvent...
...convert your CoffeeScript source to modern JavaScript. Install decaffeinate globally: npm install -g decaffeinate Call decaffeinate on each .coffee file, relaxing some options to get the most modern (and concise...
When changing code in mailers, updating the corresponding mailer preview can be forgotten very easily. Mailer previews can be tested...
...and background sections. The reason is that with background jobs (e.g. methods that are called by a cron job) some variables are not available for exception notifier, e.g. @request and...
...will crash itself and not send a mail! With foreground jobs, exception notifier gets called automatically when an error raises. For background jobs, exceptions need to be catched and delivered...
...an ActionDispatch::Request::Session object. class MyMiddlware def initialize(app) @app = app end def call(env) status, headers, body = @app.call(env) session = env['rack.session'] Rails.logger.info("Value of session['foo'] is...
...to .test("null"). Globally matching regex objects remember the last index they matched. Multiple calls to test() will advance this pointer: matcher = new RegExp("foo", "g") // <- "global" flag matcher.test("foobar...
To catch all possible exceptions from a network call, we need to rescue many error classes like this: rescue SocketError, Errno::ECONNREFUSED, Errno::ECONNRESET, Errno::ECONNABORTED, Errno::EHOSTUNREACH, OpenSSL::SSL...
...the process to have it show its progress so far. From another terminal, simply call (be root or use sudo): pkill -USR1 dd This makes dd write something like this...
...to warn the user about unsaved changes. To trigger the alert, you have to call preventDefault() on the event. Note The beforeunload event is only dispatched when the user navigation...
...alert in Chrome < 119 You might want to return any string from the event callback as this was the mechanism to trigger the alert in older browsers You cannot use...
Example This means, that we are able to overwrite these methods or call the parent version with super depending in which order and in which way they were...
A list of clever debugging tricks. TOC: Advanced Conditional Breakpoints monitor() class Calls Call and Debug a Function Pause Execution on URL Change Debugging Property Reads Use copy() Debugging HTML/CSS
end Watch Tobias Pfeiffer's talk: Do You Need That Validation? Let Me Call You Back About It Talk with your mentor about the motivations behind the use of...
Find and talk about examples where a method should better live in a callback and vice versa Find a composition of classes and move the child classes into the...
Hint: For better testability, write a service class with the functionality and only call it in your rake task Use a namespace to rename your task to rake app...
Debouncing a method call delays its execution until after a specified time has passed. If it's called again before that time has passed, its execution is delayed again.
...Here is a small 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) } }