In this card we will learn to write code that scales with a large number of database records. We will do this by pushing work out of Ruby and into...
...a scope of movies matching the following query format: The query is a list of space-separated words that all need to appear in the movie title for the movie...
Most forms have a single submit button that will save the record when pressed. Sometimes a form needs additional submit buttons like "accept" or "reject". Such buttons usually attempt...
...a state transition while updating the record. To process a form with multiple buttons, your server-side code will need to know which button was pressed. To do so you...
Note: Consider using MATE instead of Gnome 3 on newer system Awesome is a very good tiling window manager that provides neat features like automatic layouting of windows, good multi...
Improve your font-rendering Copy /etc/xdg/awesome/rc.lua to ~/.config/awesome/rc.lua. Take a look, it's pretty self-explanatory. You can instantly apply changes by reloading Awesome with Meta-Ctrl-R.
...HTML's accepts a single file. You can allow multiple files via . But sometimes, selecting multiple files is not enough and can be cumbersome for the user. Enter webkitdirectory:
...webkitdirectory switches the browser's file picker to select a directory. All files inside that directory, and inside any nested subdirectories, will be selected for the file input.
...status code 400) |_http-title: 400 The plain HTTP request was sent to HTTPS port | ssl-cert: Subject: commonName=www.makandracards.com/countryName=DE | Not valid before: 2015-10-14T12...
...Not valid after: 2016-10-14T12:42:03+00:00 |_ssl-date: 2016-08-05T11:33:52+00:00; +9d23h48m18s from local time. | tls-nextprotoneg: | h2
...is hard coded. A popular example is extension_allowlist, which returns an array of strings and let's you only upload files that have a filename with an extension that...
...matches an entry in that array. Another useful validation can be size_range, which gives you a little bit of control over how your storage gets polluted.
This card compares patterns to store trees in a relation database like MySQL or PostgreSQL. Implementation examples are for the ActiveRecord ORM used with Ruby on Rails, but the techniques...
We will be using this example tree (from the acts_as_nested_set docs): root | +-- Child 1 | | | +-- Child 1.1 | | | +-- Child 1.2 | +-- Child 2 | +-- Child 2.1 | +-- Child 2.2
...update your window title whenever you switch directories, simply specify a PROMPT_COMMAND environment variable. set-window-title() { echo -en "\033]0;$(pwd | sed -e "s;^$HOME;~;")\a" } if [[ "$PROMPT...
...COMMAND" ]]; then export PROMPT_COMMAND="$PROMPT_COMMAND;set-window-title" else export PROMPT_COMMAND=set-window-title fi You may put that into your ~/.bashrc to persist and automatically activate...
When restoring a barman PITR backup you may encounter this error: Copying required WAL segments. EXCEPTION: {'ret': 2, 'err': '/bin/sh: 1: cannot open /var/lib/barman/foopostgres/wals/00000007.history: No such file\n', 'out': ''}
...present in the wals directory of your backup. The most likely reason is that someone deleted this file in the past. If you do not need this file for restoring...
Stepping forward from JavaScript Basics, the goal of this card is for you to be able to read and write more complex ES6+ code. The JavaScript Object Model
...s also a video of that talk in our internal library. The first three sections of the article Inheritance and the prototype chain on mdn also gives a good introduction...
The maintenance mode is enabled on all application server as soon as the file /public/system/maintenance.html is present. Installation Add this line to your application's Gemfile: gem 'capistrano...
...application's web interface by writing a #{maintenance_basename}.html file to each web server. The servers must be configured to detect the presence of this file, and if it...
When you need test images, instead of using services like lorempixel or placehold.it you may generate test images yourself. Here we build a simple SVG image and wrap it into...
...a data: URI. All browsers support SVG, and you can easily adjust it yourself. Simply set it as an image's src attribute. JavaScript Simple solution in modern JavaScript, e.g...
...handy when values have an implicit ordering. Let's imagine a record Issue(criticality: string). criticality should have the following three possible values: critical, medium, low. Sorting with Issue.all.order(criticality...
...critical' issue This happens because the database column backing the criticality attribute is a string and PG will use a collation to determine the result of comparisons. In most collations...
...behavior, you can explicitely tell ActiveRecord how to preload associations with either JOINs or separate queries. This card gives an overview of the different options to preload associations, but
...for preloading! Please have a look on on our card why you should be super careful with complex eager_load or includes queries. Thus, as a general guideline.includes or .eager...
...the everyday use without any parameter tweaking I'm using a collection of tiny scripts in my ~/bin folder that can then be used as bash functions. And: It's...
...video-to-audio /path/to/cake.mp4 cake.mp3 audio-to-audio /path/to/cake.mp3 cake.aac image-to-image /path/to/cake.png cake.jpg stateDiagram-v2 text --> image: Dall-E 3 text --> audio: GPT TTS image --> text: GPT Vision...
When debugging slow SQL queries, it’s helpful to understand the database engine's query plan. Whenever you execute a declarative SQL query, the database generates a "query plan" that...
...outlines the exact steps the engine will take to execute the query. Most of the time, we don’t need to worry about this plan because SQL engines are highly...
...browser trust the certificate so it does not show warnings for your own certificate. Easy: self-signed certificate To just create a certificate for localhost, you can use the following...
...can then access your application at https://localhost:3000/. Your browser will complain about the self-signed certificate, but you can ignore the warning in that case, since you are...
...in coding lies in crafting precise prompts. The main challenge is learning how to structure prompts effectively to guide the model toward accurate results. Further evidence supporting this is the...
...that Aider already writes ~70% of its own code (as of 02/2025). However, when starting out, your results may fall short of efficiently generating large portions of your code with...
...some behavior you may eventually run into when upgrading your application. This aims to save you some time understanding what happens under the hood to possibly discover problems faster as...
...renamed to denylists. You will have to rename all occurrences in your code. Make sure that you have defined a trait for validating the extensions and content types in all...
This card is a general reminder to avoid the short version of a command option in shared code. It's much easier to understand a command and search for an...
...option when it's written out. You can still use the short version of the options in your own terminal or in code snippets that are more useful when they...
...or not to gem": Gem is really needed (prefer writing your own code for simple requirements without many edge cases) Gem is tested well (coverage and quality)
...the project requirement Try to avoid gems that do much more than your requirement scope needs Gem has a good maturity and maintenance Gem has a good / familiar DSL
...you want to automatically delete old container images from your Elastic Container Registry, the solution is a quite simple ECR Lifecycle Rule that deletes images e.g. 7 days after they...
...is a floating tag always associated with the image currently deployed to production, the situation suddenly is not so simple any more. ECR does not provide a keep action in...
A common task in web applications is to add client-side JavaScript behavior to existing HTML elements. For instance, in Working with the DOM you built a movie counter...
...JavaScript for both lists? For this your JavaScript must be abstract enough to not contain screen-specific references (such as selectors or URLs). Note that it's OK for the...
...It must be fixed by patching the Jasmine sources. Fix for Webpacker Add the package string-replace-loader to your package.json. If you're on Webpacker 5 (Webpack 4) the...
...your config/webpack/environment.js: environment.loaders.prepend('fix-jasmine4-global-detection', { test: /jasmine-core\/lib\/jasmine-core\/jasmine\.js$/, use: [{ loader: 'string-replace-loader', options: { search: 'window.toString() === \'[object GjsGlobal]\'', replace: 'window.toString() === \'[object Window]\'' } }] }) Fix for ESBuild...