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The introduction to Reactive Programming you've been missing

(by @andrestaltz)

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This tutorial as a series of videos

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.

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ukazap

Multiple SSH Keys settings for different github account

create different public key

create different ssh key according the article Mac Set-Up Git

$ ssh-keygen -t rsa -C "your_email@youremail.com"

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.SVGIcon {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;

  /* fix webkit/blink poor rendering issues */
  transform: translate3d(0,0,0);

  /* it's better defined directly because of the cascade shit
  width: inherit;
  height: inherit;

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Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

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[Unit]
Description=Puma Rails Server
After=network.target

[Service]
Type=simple
User=deploy
WorkingDirectory=/home/deploy/app/current
ExecStart=/home/deploy/.rbenv/bin/rbenv exec bundle exec puma -C /home/deploy/app/shared/config/puma.rb
ExecStop=/home/deploy/.rbenv/bin/rbenv exec bundle exec pumactl -S /home/deploy/app/shared/tmp/pids/puma.state stop

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###Sketch trial non stop

Open hosts files:

$ open /private/etc/hosts

Edit the file adding:

127.0.0.1 backend.bohemiancoding.com

127.0.0.1 bohemiancoding.sketch.analytics.s3-website-us-east-1.amazonaws.com

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If you're running a Rails app in Google App Engine's flexible environment, it takes a bit of setup to get to a rails console attached to your deployed environment. I wanted to document the steps for my own reference and also as an aid to others.

1. Open the Google App Engine -> instances section of the Google Cloud Platform (GCP) console.

2. Select the "SSH" drop-down for a running instance. (Which instance? Both of my instances are in the same cluster, and both are running Rails, so it didn't matter for me. YMMV.) You have a choice about how to connect via ssh.

   1. Choose "Open in browser window" to open a web-based SSH session, which is convenient but potentially awkward.

   2. Choose "View gcloud command" to view and copy a gcloud command that you can use from a terminal, which lets you use your favorite terminal app but may require the extra steps of installing the gcloud command and authenticating the gcloud command with GCP.

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Optimistic Locking assumes that a database transaction conflict is very rare to happen. It uses a version number of the record to track the changes. It raise an error when other user tries to update the record while it is lock.

usage

Just add a lock_version column to the table you want to place the lock and Rails will automatically check this column before updating the record.

Pessimistic locking assumes that database transaction conflict is very likely to happen. It locks the record until the transaction is done. If the record is currently lock and the other user make a transaction, that second transaction will wait until the lock in first transaction is release.

usage

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[Install]
WantedBy=multi-user.target

[Unit]
Description=Google Cloud Compute Engine SQL Proxy
Requires=networking.service
After=networking.service

[Service]
Type=simple

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# We have to remove validations on email, as it's no longer needed.
# Based on a solution found at http://stackoverflow.com/questions/7545938/how-to-remove-validation-using-instance-eval-clause-in-rails
Model.class_eval do
  _validators.reject!{ |key, _| key == :field }


  _validate_callbacks.each do |callback|
    callback.raw_filter.attributes.delete :field
  end