#Formkit

An Objective-C library for creating forms easily.

##Quick start

###Creating a form

We have included FKFormViewController, a convenient UIViewController subclass to create and show a form.

As an example, these are the steps to create a view controller that shows a login form:

First, subclass FKFormViewController

@interface FKLoginViewController : FKFormViewController
@end

Next, set the form property. FKFormViewController has a form property. During initialization, configure and set form in your subclass as follows:

FKForm *form = [[FKForm alloc] init];
form.title = @"Sign In";
    
FKRowItem *row1 = [form addRow];
[row1 addColumnWithItem:[FKTextFieldItem textFieldItemWithName:@"username" label:@"Username" text:nil placeholder:@"Email address"]];
    
FKRowItem *row2 = [form addRow];
[row2 addColumnWithItem:[FKTextFieldItem textFieldItemWithName:@"password" label:@"Password" text:nil placeholder:nil]];
    
form.purpose = FKFormPurposeSubmit;
form.submitLabel = @"Sign In";
    
self.form = form;

Lastly, perform any customization in viewDidLoad. The view associated with the form will be available at this point of time:

FKTextFieldItem *passwordItem = (FKTextFieldItem *)[self.form inputItemNamed:@"password"];
FKTextFieldView *passwordField = (FKTextFieldView *) passwordItem.view;
passwordField.textField.secureTextEntry = YES;

###Submitting the form FKFormViewController provides methods which you can override for handling form submission and cancellation actions.

//Methods to override in subclass, do not call directly
-(void)cancel:(id)sender;
-(void)submit:(id)sender;

For example, you can do the following in your subclass:

-(void)submit:(id)sender {
    //get all the form values
    NSDictionary *allFormValues = [self.form allValues];
}

##Formkit Design

###Formkit class hierachy

The two base classes of Formkit are FKFormItem and FKFormItemView. Each FKFormItem subclass is related to a FKFormItemView subclass.

• FKFormItem

  • FKForm
  • FKRowItem
  • FKColumnItem
  • FKInputItem
    • FKTextFieldItem
    • FKSelectFieldItem
    • Other input model classes...

• FKFormItemView

  • FKFormView
  • FKFormRowView
  • FKFormColumnView
  • FKInputControlView
    • FKTextFieldView
    • FKSelectFieldView
    • Other input view classes

###What makes up a form

In Formkit, each form is represented as a tree with the root being an instance of FKForm.

An FKForm contains 1..N FKRowItems representing rows.

Each FKRowItem contains 1..N FKColumnItems representing columns.

Each FKColumnItem contains a single FKInputItem subclass object representing an input field.

###Extending formkit

####writing your own input controls

As an example, let's implement a text area input control, FKSampleTextAreaItem.

Firstly, subclass FKInputItem, override viewForItem.

@interface FKSampleTextAreaItem : FKInputItem

In the implementation, override viewForItem to return an instance of the view class for this input control.

-(FKFormItemView *)viewForItem {
    return [FKSampleTextAreaView new];
}

Secondly, subclass FKInputControlView.

@interface FKSampleTextAreaView : FKInputControlView

In the implementation, override heightForWidth: and reload methods.

-(CGFloat)heightForWidth:(CGFloat)width {
    return kTextAreaViewHeight;
}

-(void)reload {
    
    FKSampleTextAreaItem *input = (FKSampleTextAreaItem *)self.item;
    _fieldLabel.text = input.label;
    _textView.text = input.value;
    
    if (input.disabled) {
        _textView.editable = NO;
        _fieldLabel.textColor = [UIColor lightGrayColor];
    } else {
        _textView.editable = YES;
        _fieldLabel.textColor = self.tintColor;
    }
    
    [self setNeedsLayout];
}

The full source code for FKSampleTextAreaItem and FKSampleTextAreaView is included within demos folder of the project.