Your Existence

Proofreeded buy

Jamon Holmgren

Who am I?

@GantLaborde

Public Speaker

Writer

Coder

Trusting User Input

Crazy or Lazy?

Start with ideal API

Have smart people help!

Ideal Validation?

    # We can validate information
    valid?(98.6, :number)
    #=> true
    

Stop them at the Source

Ideal Validation?

take 2

    # We can validate user input at the source
    @username_textfield.validates(:number).on(:invalid) do
      # Alert the user!
    end
    

Validation as a Utility

1/5

# Handle common validation needs
rmq.validation.valid?('test@test.com', :email) # returns true
rmq.validation.valid?('5045558989', :usphone) # returns true
rmq.validation.valid?('90210', :uszip) # returns false

Validation as a Utility

2/5

• :email 
• :url 
• :dateiso 
• :number
• :digits 
• :ipv4
• :time 

• :uszip
• :ukzip
• :usphone 
• :strong_password
• :has_upper 
• :has_lower 
• :presence
• :length 

Validation as a Utility

3/5

    # Make it Flexable
    rmq.validation.valid?('test', :length, exact_length: 4) #true
    rmq.validation.valid?('test', :length, min_length: 4) #true
    rmq.validation.valid?('test', :length, max_length: 4) #true
    rmq.validation.valid?('test', :length, min_length: 2, max_length: 7) #true
    rmq.validation.valid?('test', :length, exact_length: 2..7) #true
    rmq.validation.valid?(' test ', :length, max_length: 5, strip: true) #true

Validation as a Utility

4/5

# Roll your own!
rmq.validation.valid?('nacho', :custom, regex: Regexp.new('nachos?')) #true

Things that validation has to think about?

• allow_blank

• white_list

Validation as a Utility

5/5

Friday

Validation as a Rule

Built on the Utility

Validation as a Rule

    # Add a rule to a textfield
    rmq(@user_email).validates(:email)
    
    # Add rule ass we append fields
    rmq.append(UITextField, :weight).validates(:digits)
    rmq.append(UITextField, :name).validates(:presence)
    
    # Check that input
    rmq(@user_email).valid?
    
    # Check every applied rule
    rmq.all.valid?

Who's Bad?

    # Useless at first
    rmq(some_selection_criteria).invalid 
    rmq(some_selection_criteria).valid
    
    # moment of judgement
    rmq.all.valid?
    
    # All invalid views as an array
    rmq.all.invalid 
    # All valid views as an array
    rmq.all.valid

Who's Bad?

# I react depending on my own state
rmq.append(UITextField).validates(:digits).on(:valid) do
 #valid
 puts "WOWZERZ field is valid <3 <3 <3"

end.on(:invalid) do |invalid|
 #invalid
 puts "NOOOOOOOOOOOOO!!!1!1"

end

Easy Come - Easy Go

    # Bye bye Guy
    rmq(some_selection).clear_validations!
    
    # Later alligator
    rmq.all.clear_validations!

Informative Errors

We can be friendly

validation_errors

    # Returns array of error messages for every invalid item in selection
    rmq.all.validation_errors
    # E.G ["Validation Error - input requires valid email."]

We can be friendly

custom error messages

    # do this in your stylesheet
    def user(st)
      #custom validation images
      st.validation_errors = {
        email: "Please check your user email and try again"
      }
    end
    
  # overrides "Validation Error - input requires valid email."

Custom Validations with Selection Rules!?!

Custom Validations with Selection Rules!?!

Custom Validation Rules

the easy way - simple regex

    append(UITextField).validates(:custom, regex: /^test$/)

Custom Validation Rules

    rmq.validation.add_validator(:first_letter) do |value, opts|
        value.start_with?(opts[:letter])
    end

Mark Rickert (aka the "Bad Boy of RubyMotion")

Hangin' with BroBama

The Future of Validation