PureForm — the easiest way to build form such as login, questionnaire and etc. screens from JSON file. PureForm provides parsing properties and special params into objects for further manipulation of them.

Setup

Manually

Download the source files from the PureForm subdirectory. Then just add source files to your Xcode project and import the PureLayout.h header.

Cocoapods

Add the pod PureForm to your Podfile:

platform :ios, '8.0'

target 'YourProject' do
    pod 'PureForm'
end

Then, run the following command:

$ pod install

Usage

PureForm is clean and pretty easy to use in several steps:

1. Describe your form in a JSON file using JSON Rules paragraph below;

2. Create settings via PFSettings using Settings paragraph below:

   PFSettings *settings = [[PFSettings alloc] init];
   settings.keyboardTypeValidation = YES;
   settings.keyboardAvoiding = YES;
   settings.formDelegate = self;
   settings.tableViewDelegate = self;
   
   // etc.

3. Create a PFFormController instance with a UITableView and settings which were created at the previous step:

   self.formController = [[PFFormController alloc] initWithTableView:self.tableView settings:settings];

4. Just use a makeFormWithJSONFile: method to create and display your form from the JSON file from the first step:

   [self.formController makeFormWithJSONFile:@"form"];

5. That's it!

Settings

The settings header is fully documented. There are main params here you can set:

• keyboardTypeValidation
• keyboardAvoiding
• failureReasons
• cellHeight

As well as delegates for UIKit controls:

• PFFormDelegate
• UITableViewDelegate
• UITextFieldDelegate
• PFSegmentedControlDelegate
• PFSwitchControlDelegate
• PFSliderControlDelegate
• PFStepperControlDelegate

JSON Rules

Describe your custom cell in JSON just using property names and values for them. Of course, reserved words and special chars are used too. You can find reserved words and special chars in a constants header.

Basics

• Pairs of class cell name or cell identifier and reserved words are segregated by < and >.
• The base structure for 2 cells looks like (pay attention on levels):

[									   		    /// 0 level
 {
   "<cell_class_name + cell_identifier>": {   // First cell
     property_name_1: {					   /// 1 level
       in_property_name_1.1: value,		   /// 2 level
       in_property_name_1.2: value
     },
     property_name_2: {
       in_property_name_2.1: value
     }
   }
 },
 {
   "<cell_class_name + cell_identifier>": { 	// Second cell
   // Setup
 },
 {
 // etc.
 }
]

Note that JSON parsing supports only 2 levels of nesting yet.

• If a cell class name or a cell identifier equals to the previous one, you can simplify it using = like that:

{
   "<= + =>": { 									// Any cell
   // Setup
},

• Usage of reserved words and special chars:

Reserved word	Level	Value
<section>	0	index of section
<value>	1	current value
<key>	1	save key for output dictionary
<validators>	1	array of validators
<display>	1	property name to display value after change
All reserved words and special chars are optional.

Char	Usage in	Example	Description
?	property name	textField?	Shows that it's a form for validation — not just a view
!	validator name	min_value!	Starts validation immediately after value change
*	property name	text*	Shows that this value is a key for NSLocalizedString macros
#	value	ic_turtle#6F3F83 or #6F3F83	Uses as it is or for hex coloring image by their name

• Available validator keys for <validators>:

Validator	Value
equal	string or number
equal_next	true
equal_previous	true
equal_length	number
min_length	number
max_length	number
min_value	number
max_value	number
required	true
type	email or full_name
custom	regex string
Validators are used in 2 level and they should be nested into <validators>.

• Enums are just numeric values in JSON. By the way there are some enums which are associated with string values:
  • UIKeyboardType
  • UITextAutocapitalizationType
  • UITextAutocorrectionType
  • UITextSpellCheckingType
  • UIKeyboardAppearance
  • UIReturnKeyType
  • UITextFieldViewMode

Examples

• Well, how it looks in a real example:

[
 {
   "<TextFieldCell + TextFieldCellIdentifier>": {
     "textField?": {
       "placeholder": "Huh, centered?",
       "textAlignment": 1
     }
   }
 }
]

• Now let's make a login form with validators:

[
 {
   "<TextFieldCell + TextFieldCellIdentifier>": {
     "textField?": {
       "placeholder": "Login",
       "textAlignment": 1,
       "keyboardType": "UIKeyboardTypeEmailAddress",
       "<key>": "login",
       "<validators>": {
         "type": "email"
       }
     }
   }
 },
 {
   "<= + =>": {
     "textField?": {
       "placeholder": "Password",
       "textAlignment": 1,
       "secureTextEntry": true,
       "<key>": "password",
       "<validators>": {
         "min_length!": 6,
         "max_length!": 25
       }
     }
   }
 },
 {
 "<section>": 1
 },
 {
   "<ButtonCell + ButtonCellIdentifier>": {
     "titleLabel": {
       "text": "Login",
       "textColor": "#6F3F83"
     }
   }
 }
]

• It remains only to validate entered values and save they into the dictionary. Credentials from left form satisfies the validators and [self.formController validate] will return YES:

if ([self.formController validate]) {
   NSDictionary *loginInfo = [self.formController allKeyValuePairs];
   // Send it to server
}

Notes

• Example project files will open properly only in Xcode 8.

TODO

• Remove limit of nesting
• Keyboard avoiding (issue #2)
• Targets for buttons
• Support of UITextView
• Wrapper for editing common properties