Zaim Ramlan zaimramlan

Markdown and reStructuredText

GitHub supports several lightweight markup languages for documentation; the most popular ones (generally, not just at GitHub) are Markdown and reStructuredText. Markdown is sometimes considered easier to use, and is often preferred when the purpose is simply to generate HTML. On the other hand, reStructuredText is more extensible and powerful, with native support (not just embedded HTML) for tables, as well as things like automatic generation of tables of contents.

Grab new backup of database

Command: heroku pgbackups:capture --remote production

Response: >>> HEROKU_POSTGRESQL_COLOR_URL (DATABASE_URL) ----backup---> a712

Get url of backup download

Command: heroku pgbackups:url [db_key] --remote production

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

-E: will describe the underlaying queries of the \ commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

To remove a submodule you need to:

Delete the relevant section from the .gitmodules file.
Stage the .gitmodules changes git add .gitmodules
Delete the relevant section from .git/config.
Run git rm --cached path_to_submodule (no trailing slash).
Run rm -rf .git/modules/path_to_submodule (no trailing slash).
Commit git commit -m "Removed submodule "
Delete the now untracked submodule files rm -rf path_to_submodule

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

Please note that when you call a mailer method that DEPENDS on a record ID, use this style:

UserMailer.delay_for(X.seconds).the_mailer_method(*args)

instead of this style

UserMailer.the_mailer_method(*args).deliver_later

	# Ways to execute a shell script in Ruby
	# Example Script - Joseph Pecoraro

	cmd = "echo 'hi'" # Sample string that can be used

	# 1. Kernel#` - commonly called backticks - `cmd`
	# This is like many other languages, including bash, PHP, and Perl
	# Synchronous (blocking)
	# Returns the output of the shell command
	# Docs: http://ruby-doc.org/core/classes/Kernel.html#M001111

	# Model

	expect(@user).to have(1).error_on(:username) # checks whether there is an error in username
	expect(@user.errors[:username]).to include("can't be blank") # check for the error message

	# Rendering

	expect(response).to render_template(:index)

	# Redirecting

	# The trick is to link the DeviceSupport folder from the beta to the stable version.
	# sudo needed if you run the Mac App Store version. Always download the dmg instead... you'll thank me later :)

	# Support iOS 15 devices (Xcode 13.0) with Xcode 12.5:
	sudo ln -s /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/15.0 /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport

	# Then restart Xcode and reconnect your devices. You will need to do that for every beta of future iOS versions

	# (A similar approach works for older versions too, just change the version number after DeviceSupport)

	# ...

	gem 'carrierwave'
	gem 'fog', '~> 1.0.0' # Need to specify version, as carrierwave references older (0.9.0) which doesn't allow configuration of Rackspace UK Auth URL