w4d3 - rails views

Question 1

How do you validate uniqueness of a combination?

Answer 1

validates :attribute, uniqueness: { scope: :attribute2 }

Question 2

What do views do?

Answer 2

Generate and populate the Response object

Question 3

What context is a view evaluated in?

Answer 3

the controller

Question 4

How do you render a view named show.html.erb?

Answer 4

render :show

Question 5

How do you delete the current line in atom?

Answer 5

CMD + X

Question 6

What’s the relationship between the new/create actions?

Answer 6

new - render a form

create - receive the form data and act on it

Question 7

What’s the relationship between the edit/update actions?

Answer 7

edit - renders the form

update - receives form data and acts on it

Question 8

What params would you send into a url helper?

Answer 8

wildcards

note that if you send in a model, its id will be populated automatically

Question 9

What are the two ways of setting up a label?

Answer 9

For:
[label for=’id_of_thing’]body[/label]

Subling/wrap:
[label]body[input type=’text’/][/label]

Question 10

What’s the difference between #update_attributes and #update?

Answer 10

They’re the same (alias for one another)

Question 11

Where do you generally redirect to?

Answer 11

The model_url helper, where model is the name of the model

Question 12

How can a form send an array back within the post params?

Answer 12

input name=’model[array_name][ ]’

Use this multiple times within the same form.

Question 13

What’s the primary function of cookies?

Answer 13

To preserve state between HTTP requests

Question 14

What are the 2 primary distinctions between hashing functions and cryptographic hashing functions?

Answer 14

1. Speed. Cryptographic is slower.

2. Collisions. Cryptographic creates far fewer collisions.

Question 15

How do you see the class inheritance path for an object?

Answer 15

objectname.class.ancestors

Question 16

How do you access cookies that are stored only until the next request cycle?

How would you render this in a view?

Answer 16

flash[:some_error] = ‘whatever’

[%= flash[:some_error] %]

Question 17

What’s the principle behind CSRF protection?

Answer 17

Each form should have a param with a unique code that is associated with the user’s session.

When a form is submitted, if the code does not match up, we assume a CSRF attempt and raise an error.

Question 18

How does rails implement CSRF protection?

Answer 18

in every one of your forms, you add an input/hidden with

name=”authenticity_token”

and

value =
[%= form_authenticity_token %]

Question 19

How do you enable automatic CSRF protection per controller? Per site?

Answer 19

• -per controller:
  self. per_form_csrf_tokens = true

–per site:
config/application.rb:
Rails.configuration.action_controller.per_form_csrf_tokens = true