Features

• Generating a project README
• Finally: Support for modelling associations between models in your application model! Example:

# lib/katapult/application_model.rb

model 'Cart' do |cart|
  cart.belongs_to 'User'
end

crud 'User' do |user|
  user.attr :fullname
end

When you have a pending Cucumber step (or feature) that also uses an existing VCR cassette, your pending test may fail at the very end with an error like this:

There are unused HTTP interactions left in the cassette:
  - [get ...] => [200 ...]
  - [get ...] => [200 ...] (VCR::Errors::UnusedHTTPInteractionError)

The error happens because your VCR is configured to complain about cassettes that contain extra requests which your test did not use. This is often a good configuration.
If you do not want to change your whole test suite...

Katapult 0.3.0 brings Rails 5 and Ruby 2.5 support with a new design, plus a ton of smaller features, fixes and improvements.

Features

• Generating a Rails 5.1.4 app on Ruby 2.5.0
• Dropped asset pipeline in favor of Webpacker
• The generated application now has a sleek, simple design based on Bootstrap
• Employing Unpoly
• New application model DSL shortcut crud for "create a model and a web UI with crud actions"
• The generated application model is now a transformable e...

Enumerable#all? returns true for an empty collection. This totally makes sense but you have to think about it when making assumptions on relations which might be empty.

[].all?(&:will_never_be_called_here) => true

Example with empty collection

class Researcher < ActiveRecord::Base
  has_many :papers
end

class Paper
  validates :topic, inclusion: { in: ['computer_science', 'mathematics', 'economy'] }
end

Easy goal: Delete all researches who write onl...

Say you want to move a git repository from one remote (perhaps Github) to another (perhaps Gitlab).

If you have the repo checked out, you still should make sure to mirror all branches of the old remote, not only those you happen to have checked our. Otherwise the target repo will become a copy of your current repo, and not the source repo, potentially missing commits. You can use this:

git remote rename origin old-origin
git remote add origin <new-remote>
git fetch old-origin --prune
git push --prune origin +refs/remotes/old-origin/*:r...

This cucumber step is useful for testing an image (looking at the src of the image).

Then(/^I should see the image "([^"]*)"$/) do |filename_with_extension|
  expect(page).to have_css("img[src*='#{filename_with_extension}']")
end

Then I should see the image "placeholder.png"

Outline: Read more about how to test a uploaded file here, e.g. file downloads.

ActiveSupport::Dependencies takes care of auto-loading any classes in development. This is usually useful, but when you run into issues with the Rails autoloader, you should take a look at what it's doing.

For me this was useful in an "exciting" case of auto-loading classes inside a thread which caused the application to stop responding.

Rails 4.x

ActiveSupport::Dependencies includes logging support. It is easy to use:

ActiveSupport::Dependencies.logger = Rails.logger

Rails 5+

[Logging support was removed](https://github...

This is an extension to PostgreSQL vs MySQL: How to UPDATE using a JOIN.

UPDATE employees
SET department_name = departments.name,
  department_area = areas.name
FROM departments, areas
WHERE employees.department_id = departments.id
AND departments.id = areas.department_id

About-Payments is here to help you to accept payments online and
find the best payment service provider for your e-commerce business.

Using CSS sprites for background images is a technique for optimizing page load time by combining smaller images into a larger image sprite.

There are ongoing arguments on how useful this still is, as modern browsers become more comfortable to load images in parallel. However, many major websites still use them, for example amazon, [facebook](...

PostgreSQL offers a really handy field type: json. You can store any JSON there, in any structure.

While its flexibility is great, there is no syntactic sugar in Rails yet. Thus, you need to manually query the database.

Demo

# Given a Task model with 'details' json column
Task.where("details->>'key' = ?", "value") # matches where 'details' contains "key":"value"
Task.where("details->>'{a,b}' = ?", "value") # matches where 'details' contains "a":{"b":"value"}
Task.where("details->'a'->>'b' = ?", "value") # same as above, but vi...

Font Awesome version 5 changed some icon names, and introduces new prefixes fab, far, and fas.

There is a JavaScript shim that you can use as a "quick fix". It allows you to keep v4 icon names on v5.

The linked page includes details on using that, and a migration guide including a list of icon renames.

To check which elements an ActiveRecord relation contains use the contain_exactly matcher.

describe User do
  let!(:admin) { create(:user, role: 'admin') }
  let!(:customer) { create(:user, role: 'customer') }
  
  subject(:users) { User.where(role: 'admin') }
  
  # Recommended (The error output is most helpful)
  it { expect(users).to contain_exactly(admin) }
  
  # Other options
  it { expect(users).to eq([admin]) }
  it { expect(users.pluck(:id).to eq([admin.id]) }
end

In case you have an `ActiveRecord::AssociationRelati...

With "attaching an event handler once" you possibly mean one of these two things:

Register a function for an event, and discard it once that event has happened

Use one instead of on.

$(element).one('eventName', function() { ... });

It has the same API has on.

When code is run multiple times that registers a function for an event, do that only once

With jQuery, you can de-register callbacks. You can use that to achieve registering a function only once.

function myAction() { ... }; // defined somewhere globally o...

This article will show you how to use throw and catch. It's a nice tool to break out of multiple loops when a result is obtained.

Also see our card Ruby: A small summary of what return, break and next means for blocks.

This is painful. Consider using Microsoft Office or switching careers. If you need to write < 20 letters consider doing it manually.

So you didn't listen and here it comes:

1. Ignore the Mail Merge Wizard. It will crash or destroy your document.
2. Export your addresses, recipient names, etc. as a .ods spreadsheet (.xls, .xlsx, .ods). Use any columns that work for you, but be consistent. I like to use one column for the address, one column for the salutation line.
3. Import the spreadsheet as an address book source: *Tools => Add...

This error is raised because your old database does not have a configured environment yet, which Rails 5 enforces.

If this error occurs while migrating your parallel test databases, make sure to update the parallel_tests gem first: current versions fix this. If you're still using Cucumber < v3, the latest version of parallel_tests will be 2.18.0.

Since we are using LoDash instead of UnderscoreJS in recent/current projects, you should keep 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]

If you want to chain multiple calls, you need to start off with a _.chain, and call value() to terminate the chain.

_.chain(x).uniq().map(function(i) { return i + 10 }).reverse().value() // => [12, 11]

##...

To find and replace (CTRL + H) empty cells in Libre Office Calc you can use a regular expressions (also called "Finds an empty paragraph" in context of a spreadsheet):

It is also possible to just enter a regular expression in the search (CTRL + F), but there is no option to only search in the current selection like in the screenshot above. Use find and replace instead if needed.

When making requests using curl, no cookies are sent or stored by default.
However, you can tell curl to re-use cookies received earlier (or forge your own cookies).

There are 2 command line switches you need to use:

• -c will write cookies to a given file
• -b will read cookies from a given file

Example

The remote server sets a "foo" cookie to value "bar". We tell curl to store them to a file at /tmp/cookies using the -c switch.

$ curl -c /tmp/cookies http://httpbin.org/cookies/set?foo=bar

You may look at the file, ...

You should avoid using application models in your migrations. But how else could you create records in a migration?

The most basic way is to write plain SQL, but since INSERT statements are no pleasant write for Rubyists, here is a simple wrapper:

Record creation helper for migrations

The helper method below takes a table name and a hash of attributes, which it inserts into the specified table. Copy it over to your migration and profit!

  private

  def insert_record(table, **attributes)
    attributes.merge!...

The gist is:

• wrap the text with a span
• use line-height for the spacing between lines ("margin")
• use box-shadow to control the line background size ("padding")

Example

span
  box-shadow: 0 0 0 10px #fff
  background-color: #fff
  box-decoration-break: clone # Fix Firefox
  line-height: 2.2

→ [jsfiddle](https://jsfiddle.net/2fmqgbh...