Don't sum up columns with + in a sql-query if NULL-Values can be present. MySQL and PostgreSQL cannot sum up NULL values with the + value. The sum value...
MySQL: mysql> select 1 + 2 + 3; +-----------+ | 1 + 2 + 3 | +-----------+ | 6 | +-----------+ 1 row in set (0,00 sec) mysql> select 1 + NULL + 3; +--------------+ | 1 + NULL + 3 | +--------------+ | NULL...
...popup on all browsers. When you integrate a date picker popup, remember to also set autocomplete="off" on the text input that opens the calendar on click. Otherwise the autocomplete...
...suggestions will cover the calendar box and make it unusable: If you are using a tool like Unpoly you might want to set autocomplete="off" in the JavaScript that also...
If the project team consists of at least 2 members, do a daily standup. It should not take much longer than 15 minutes. Format Tell everyone else
if there are new developments everyone needs to know about A "still working on X, will probably be done today" is totally fine. No need to tell...
It's possible to implement simple custom RuboCop cops with very little code. They work exactly the same like existing rubocop cops and fail the pipeline if they find an...
...offense. This is handy for project specific internal rules or conventions. The following cop looks at every ruby file and searches for TODO or WIP comments and adds an offense...
The Web Animations API has great browser support, and you should be using it to animate DOM elements from JavaScript, or to control or wait for CSS animations.
...Its API probably a bit different from how your favorite frontend framework animates, but simple enough to get used to. Like for CSS animations, you specify keyframes to animate. This...
In my experience, the most common sources of memory leaks are APIs like these: addEventListener. This is the most common one. Call removeEventListener to clean it up. setTimeout / setInterval. If...
...you create a recurring timer (e.g. to run every 30 seconds), then you need to clean it up with clearTimeout or clearInterval. (setTimeout can leak if it’s used like...
Let's say you want to find the element with the text hello in the following DOM tree: hello world You might think of XPath's contain() function: page.find(:xpath...
...contains(text(), 'hello') and not (./*[contains(text(), 'hello')])]") With jQuery jQuery has a custom selector :contains() that you can use in the same fashion: $(":contains('hello'):not(:has(:contains('hello...
The standard way to abort async code is that your function takes a AbortSignal { signal } property. The caller can use this signal to send an abort request to your function...
...with a new DOMException('Message here', 'AbortError') when canceled. This already has good browser support and can be polyfilled on older browsers. Example Here is an async function countDown(). It...
...automatically. If you delete records regularly, this may be an annoyance. Here is a solution which was adapted from the Carrierwave GitHub wiki and cleans up any empty parent directories...
class ExampleUploader < CarrierWave::Uploader::Base storage :file after :remove, :remove_empty_container_directory def store_dir # You implemented this in your uploaders already. end def remove_empty...
If you already selected an element and want to get its parent, you can call find(:xpath, '..') on it. To get the grand-parent element, call find(:xpath, '../..'). Example
...href]).to eq("http://twitter.com/") About XPath There is a good overview on XPath syntax on w3schools. But as XPath expressions can get quite complex and hard to understand for...
If validations failed for a record, and you want to find out if a specific validation failed, you can leverage ActiveModel's error objects. You rarely need this in application...
...name (e.g. :blank for :presence, :taken for :uniqueness). You may also use where to see all errors of an attribute: >> user.errors.where(:email) => [#<ActiveModel::Error attribute=email, type=blank, options={}>]
Cucumber up to version 2 had a neat feature called Step Argument Transforms which was dropped in favor of Cucumber 3 ParameterTypes. While I strongly encourage you to drop your...
...keep the exact same functionality of your old Transforms while writing them in the style of new ParameterTypes. Why would I want to keep my Transforms? Transforms allowed you to...
...of passwords for the root user and you prefer using a password for root. Solution Step 1 is getting a root mysql shell that allows us to change user credentials...
...and MySQL since they share names of binaries. sudo systemctl stop mysql sudo mysqld_safe --skip-grant-tables & This starts the mysql daemon in the background and we can now...
Our preferred way of testing ActiveRecord is to simply create/update/destroy the record and then check if the expected behavior has happened. We used to bend over backwards to avoid touching...
...the database for this. For this we used a lot of stubbing and tricks like it_should_run_callbacks. Today we would rather make a few database queries than have...
To query for identical arrays independent of their order you have to either: Sort both the query and database content. If you're on Rails 7.1 you can use...
...the new normalizes macro for this. This solution would still use any indexes on the column. Check for inclusion in both directions, as implemented by the where_array_matches method...
...is defined incorrectly. Raise the attributes hash given to your :reject_if lambda to see if it looks like you expect. If you are nesting forms into nested forms, each...
...a new parent record together with a new child record and will need to save the parent before you can save the child. You can opt to only show the...
...the cogwheel icon (or press F1 when focusing the dev tools) to open the settings overlay. Under "Preferences", in the "Appearance" section, find the "Panel layout" option. Set it to...
Alternatively, press Ctrl+Shift+P and search for "panel layout". Wat? Vertical means that the DOM tree is next to the styles/etc panel, like so:
...an error if your application logic ever violates it. class User < ApplicationRecord has_one :session, dependent: :destroy end class Session < ApplicationRecord belongs_to :user end create_table :users do |t...
end create_table :sessions do |t| t.references :user, null: false, foreign_key: true, index: { unique: true } # Don't forget the uniqueness here t.timestamps
...you have too many inotify instances you may run into limits of your operating system. To find out which process is using them all up you can run:
...to lock a user in devise. Using the lockable module Customizing the user account status validation when logging in. It depends on your requirements which methods works best.
...user on soft delete We recommend to use option 2 when you want to couple the lock to the model's soft delete logic. Option 1 might also work when...
...For ages, CSS transforms had to be defined using the transform property. For a single transformation, this was something like transform: scale(1.5), and multiple transformations could be applied by...
.example { transform: scale(1.5) rotate(45deg) translateY(-50%); } All modern browsers (Chrome & Edge 104+, Firefox 72+, Safari 14.1+, Samsung Internet 20+) also support individual properties for transforms.
...instead of using the UI or creating records in the Rails console. This approach saves time and gives you useful defaults and associations right out of the box.
Or: How to avoid and refactor spaghetti code Please note that I tried to keep the examples small. The effects of the methods in this card are of course much...
...more significant with real / more complex code. What are the benefits of more modular code? Code is written once but read often (by your future self and other developers who...
ImageMagick can convert SVGs to raster image formats. Example for PNG: convert input.svg output.png If the SVG has a size of 24x24 (viewBox="0 0 24 24"), the resulting...
...PNG will also have a size of 24x24. Resizing An SVG's viewBox specifies the intended size, but vector image formats can be scaled freely. Resize flag (poor results)