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Ruby Style Guide Notes

https://github.com/JuanitoFatas/ruby-style-guide

• Always run the Ruby interpreter with the -w option so it will warn you if you forget either of the rules below!
• Use ||= freely to initialize variables.

# set name to Bozhidar, only if it's nil or false

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Friendly URLs

By default, Rails applications build URLs based on the primary key -- the id column from the database. Imagine we have a Person model and associated controller. We have a person record for Bob Martin that has id number 6. The URL for his show page would be:

/people/6

But, for aesthetic or SEO purposes, we want Bob's name in the URL. The last segment, the 6 here, is called the "slug". Let's look at a few ways to implement better slugs.

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Review of Confident Ruby

Read API doc

1. any? [{ |obj| block }] → true or false means could either accept 0 or 1 { |obj| block } block.

2. send(symbol [, args...]) → obj means could either accept 0 or many argumetns. if symobol method accept block, then may also appen that block to it, e.g. define_method.

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Xor and Sum

You are given two positive integers a and b in binary representation. You should find the following sum modulo 10 ^ 9 + 7:

Summation(a xor (b shl i)) from i = 0 to 314159

where operation xor means exclusive OR operation, operation shl means binary shift to the left.

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• Item 6

• Ruby find a method by searching its suplerclass until to the top, then back to original class then searching the hierachy for method_missing again.

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// example object

var obj = {'property': 1234}

Object & Prototype

1. Everything is object, except null and undefined.

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Lecture 1

1. Constraint and auto layout.

• Auto Layout Concepts
• The attributes leading and trailing are the same as left and right for left-to-right languages such as English, but in a right-to-left environment such as Hebrew or Arabic, leading and trailing are the same as right and left.
• Constraints are cumulative, and do not override each other. Setting a second width constraint for a view does not remove or alter the first width constraint.

2. @IBOutlet weak var prpoerty.

• Outlets

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#Weird Part Of JS

1. this is global object if there does not have receiver. If so, it also imply it is a window object, document === window.document.

2. JS engine create this execution context(window object) in bottom of execution stack and run other execution context which is in top of it for you.

3. When you declare a var or define as a function(function expression or function statement), you can find it through window.func() or func() in global environment.

4. Hoisting: var and func are all firstly initialize but not assigned its value yet until the later code assign it. Check code example below.

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Process:

1. git clone git@github.com:rails/rails.git

2. git branch -b <new_branch>

3. git checkout <new_branch>

4. code work, add CHANGELOG.md

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#Rails Routing

1. We can define customed url helper by :as

   get "/photos/:id", to: "photos#show", as: :"show_photo"
   
   <%= link_to 'Photo Record', show_photo_path(15) %>
   
   show_photo_path(15)