Custom Field component with validation for creating easier form-like UI from interface builder.

#YALField

Custom Field component with validation for creating easier form-like UI from interface builder.

##Example Project To run the example project, run pod try YALField.

##Usage To successfully use YALField component you should take the following steps per each form you have:

1. Make subclass of YALBaseForm which lists fields you will have in your form like @property (nonatomic, weak) IBOutlet YALField *fieldName;.

2. Make a subclass of YALField and update it as you want. For example make also a subclass of configurator and set it to the YALField in commonInit

3. Go make a view controller, add your fields on the view, add some constraints configure properties as you want and drop a form as object onto scene at the same level as Exit and First Responder objects. Also don't forget to add finishButton of type UIButton somewhere on the view.

4. Add validators, formatters and supplementaryViews on the same level in scene as form.

5. Wire IBOutlets of every field with it's validator, formatter and supplementaryView. You can wire validator and formatter to as many fields as you want but remember you can not use one supplementaryView for more than one field.

6. Go conform YALFormFinishResponder and YALErrorsPresenter to your viewController and implement needed methods.

7. Then wire IBOutlets of form with fields, errorPresenter, finishResponder and finishButton.

8. Done!

##Requirements iOS 8 or higher.

##Installation

####CocoaPods

pod 'YALField', '~> 1.0.2'

####Manual Installation

Alternatively, you can directly add all the source files from YALField to your project.

1. Download the latest code version or add the repository as a git submodule to your git-tracked project.
2. Open your project in Xcode, then drag and drop all folder directories in Pod/ onto your project (use the "Product Navigator view"). Make sure to select Copy items when asked if you extracted the code archive outside of your project.
3. Make concrete subclasses of YALField and YALBaseForm or use them directly from interface builder and import wherever you need it with #import "YALField.h" and #import "YALBaseForm.h" or import your concrete subclasses.

##Introduction

The main two classes you need to know about is YALField and YALBaseForm. YALField is a the main ui component represents a single field of form. It conforms to protocols YALInput and YALConstraintBasedUIComponent publicly and UITextFieldDelegate and YALFieldInput privately. YALBaseForm is the model made for representing the form, and containing and managing fields of concrete form. YALBaseForm should be subclassed to have concrete models of forms like YALLoginForm or YALRegistrationForm for example which carry concrete form fields. YALBaseForm conforms to YALForm protocol.

###YALField ####Examples

####Scheme YALField is designed to consist of three parts (from left to right):

1. titleView of class UILabel (cyan)
2. textField of class UITextField (yellow)
3. supplementaryView which must be a subclass of YALBaseSupplementaryView (magenta)

####Guts YALField has a number of properties which define how it looks:

1. IBOutlet id<YALInputConfigurator> configurator
2. IBOutlet UIView *supplementaryView

and how it works:

1. IBOutlet id<YALResponder> responder
2. IBOutlet id<YALValidator> validator
3. IBOutlet id<YALFormatter> formatter

####Look ######configurator configurator define how YALField looks. You can subclass YALFieldConfigurator and set it's properties in init and/or override following methods: configureView, configureView:forState, resetView. Or you may use one directly from interface builder and modify it's properties there. One configurator may be used with multiple YALField's.

######supplementaryView supplementaryView is used as view to be added inside the YALField and used as supplementaryView. Any view subclassed from YALBaseSupplementaryView can be used as supplementaryView of YALField. supplementaryView unlike configurator can not be shared between multiple YALField's. Also supplementaryView should not have superview or in other words be someones subview until or after it's set to supplementaryView property of YALField cause in that moment it will be immediately added as subview to YALField and if you add it to any other view, well that breaks some things. YALField pod provides two basic supplementaryView's: one is used internally and is YALPasswordSupplementaryView and another one is YALValidatingSupplementaryView which is made to present validating functionality in supplementaryView. YALValidatingSupplementaryView conforms to protocol YALStateVaryingSupplementaryView which means it can receive setFieldState method and change itself whenever fieldState of YALField changes. In the example project you may see YALStepperSupplementaryView which wraps UIStepper and which is not only supplementaryView of YALField but also responder which means it handles touches recieved by YALField and also this concrete supplementaryView has field IBOutlet which must be linked to YALField that owns it so that supplementaryView may change the formattedValue of YALField. The second supplementaryView in example project is YALHalloweenSupplementaryView which is subclass of YALValidatingSupplementaryView with a slight change of pictures and pictures tint colors for different YALFieldStates.

####Work ######formatter formatter is used to format YALField value while being input from keyboard or when set from outside with rawValue setter, also formatter converts rawValue to formattedValue when formattedValue getter invoked. formatter must conform to YALFormatter protocol. One formatter may be used with many YALFields. We provide only one formatter in pod - YALLengthLimitingFormatter which can be easily used or taken as example when developing formatter by yourself. Formatters in Example project considered to much of a copy paste or to simple and unique case to be included in pod.

######validator validator should be subclass of YALBaseValidator. validator is used to validate the YALField it conforms to protocol YALValidator which has only one method - (BOOL)isValid:(id<YALInput>)input error:(out NSError **)error;. validator has a property named errorsProviderClassName which if needed should be the class name of class which should conform to protocol YALErrorsProvider and can be subclassed from YALBaseErrorsProvider. This class should provide NSError for validator + (NSError *)errorForValidator:(id<YALValidator>)validator, most of this logic is encapsulated in YALBaseValidator which means that in subclass you can just provide this class name and use - (NSError *)error to get error for validator. In pod we provide few basic validators to base your own on:

1. YALBaseValidator is validator to make your own custom validators from it.
2. YALGroupValidator provides functionality to group and order multiple validators in itself to use multiple validators on one YALField.
3. YALNonEmptyValidator takes rawValue of YALField as NSString and checks if it's not empty.
4. YALRegexValidator takes Regular Expression in regex IBInspectable property and checks if rawValue of YALField matches regex.

######responder responder is the object which conforms to protocol YALResponder and may take care of touches received by YALField by implementing methods like performAction: or becomeFirstResponder. In example project YALStepperSupplementaryView is responder of YALField to prevent YALField from user interaction. Another example in example project is birthDateResponder in YALEditProfileViewController which presents datePicker when we touch YALField birthDate.

###YALBaseForm YALBaseForm is a base class for you to subclass your forms from it as for example done YALRegistrationForm in Example project:

#import "YALBaseForm.h"

@class YALField;

@interface YALRegistrationForm : YALBaseForm

@property (nonatomic, weak) IBOutlet YALField *name;
@property (nonatomic, weak) IBOutlet YALField *phone;
@property (nonatomic, weak) IBOutlet YALField *email;
@property (nonatomic, weak) IBOutlet YALField *password;

@end

Later this form model should be wired with it's fields: Also you may notice here three not mentionet previously IBOutlets of YALBaseForm:

1. errorsPresenter is an object conforming to YALErrorsPresenter protocol which obviously will present any NSErrors recieved from form, in this concrete case it's YALRegistrationViewController superclass YALBaseViewController.
2. finishResponder is an object that conforms to YALResponder protocol and expected to respond to performAction: selector. performAction: will be invoked when the next interesting object finishButton catches UIControlEventTouchUpInside event. Also finishResponder can conform to YALFormFinishResponder protocol which means it has a property form of type YALBaseForm and it will be set if it not yet have been set when form finished.
3. finishButton is expected to be instance of UIButton. When both finishButton and finishResponder set YALBaseForm adds target self to finishButton to catch event when finisButton will be touched up inside so that form may invoke performAction: on finishResponder sending self as sender.

So in case with YALRegistrationViewController which is finishResponder of YALRegistrationForm you just catch form finish event if and only if every field in form that has a validator isValid like this:

@implementation YALRegistrationViewController

...

- (void)performAction:(YALRegistrationForm *)form {
    // collect data from form and perform real request to your API for example
    [self pretendToDoSomeNetworkRequestWithWithTitle:@"Registrering" completion:^{
        [self performSegueWithIdentifier:@"RegistrationToLogin" sender:self];
    }];
}

@end

##Author

Igor Muzyka, [email protected]

##License

The MIT License (MIT)

Copyright © 2017 Yalantis

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.