ProGM

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Table alias

seeliang

Updated on medium

find out the differences

use git diff to generate file list

git diff --name-only master

limited to certain file types

add ext filter

amirsuhail786

	" Make IE Better Compatible "

<!--[if IE]>
<script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->

======================================================
IE6 Only
==================
_selector {...}

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

alexhawkins

'use strict';

/*****************NATIVE forEACH*********************/

Array.prototype.myEach = function(callback) {
    for (var i = 0; i < this.length; i++)
        callback(this[i], i, this);
};

//tests

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

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.

---

LucasRoesler

class JSONMiddleware(object):
    """
    Process application/json requests data from GET and POST requests.
    """
    def process_request(self, request):
        if 'application/json' in request.META['CONTENT_TYPE']:
            # load the json data
            data = json.loads(request.body)
            # for consistency sake, we want to return
            # a Django QueryDict and not a plain Dict.

Kartones

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)

lfender6445

Pry Cheat Sheet

• Youtube Tutorial 2013

Command Line

• pry -r ./config/app_init_file.rb - load your app into a pry session (look at the file loaded by config.ru)
• pry -r ./config/environment.rb - load your rails into a pry session

Debugger

MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname