Jim Chen jimytc

The introduction to Reactive Programming you've been missing

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

	INSERT INTO creation_metadata (creation_id, category)
	SELECT id, type
	FROM creations
	ON CONFLICT DO UPDATE SET category = EXCLUDED.type;

	WITH creations_need_move AS (
	SELECT id, type
	FROM creations
	WHERE type IS NOT NULL
	),
	update_existing_metadata AS (
	UPDATE creation_metadata (creation_id, category)
	SET category = source.type
	FROM creations_need_move source
	WHERE creation_id = source.id

	CREATE OR REPLACE FUNCTION upsert(target_id INT, type_value TEXT) RETURNS VOID AS $$
	BEGIN
	-- Try update first
	UPDATE creation_metadata SET category = type_value
	WHERE creation_id = target_id;
	-- Return if UPDATE command runs successfully
	IF FOUND THEN
	RETURN;
	END IF;
	-- Since there's no record in creation_metada

	INSERT INTO creation_metadata (creation_id, category)
	SELECT creations.id, creations.type
	FROM creations
	LEFT JOIN creation_metadata
	ON creations.id = creation_metadata.creation_id
	WHERE creations.type IS NOT NULL
	AND creation_metadata.category IS NULL

	# Configure HttpLog to capture the detail we want to know.

	HttpLog.configure do \|config\|

	# Enable or disable all logging
	config.enabled = true

	# You can assign a different logger
	config.logger = Logger.new($stdout)

	irb(main):023:0> uri = URI('http://www.google.com')
	=> #<URI::HTTP http://www.google.com>
	irb(main):059:0> Net::HTTP.get(uri)
	D, [2018-08-13T22:33:30.030400 #19738] DEBUG -- : [httplog] Connecting: www.google.com:80
	D, [2018-08-13T22:33:30.055285 #19738] DEBUG -- : [httplog] Sending: GET http://www.google.com:80/
	D, [2018-08-13T22:33:30.055377 #19738] DEBUG -- : [httplog] Header: accept-encoding: gzip;q=1.0,deflate;q=0.6,identity;q=0.3
	D, [2018-08-13T22:33:30.055412 #19738] DEBUG -- : [httplog] Header: accept: /
	D, [2018-08-13T22:33:30.055579 #19738] DEBUG -- : [httplog] Header: user-agent: Ruby
	D, [2018-08-13T22:33:30.055605 #19738] DEBUG -- : [httplog] Header: host: www.google.com
	D, [2018-08-13T22:33:30.055646 #19738] DEBUG -- : [httplog] Data:

	# Add it to Gemfile
	gem 'httplog'

	# Install the gem
	$ bundle install