Managing Multiple Views and Segues FA 172 Intro to Mobile App Development

Multiple Views Recall the RiddleApp the class created on the first day of classes Used a navigation controller, multiple views, and segues For today, we will learn to manage multiple views and pass data (objects) between views

Product inventory app Three projects ProductInvAppPrototype – Focus on user interface ProductTest – Focus on testing an existing product class ProductInvApp – Create the final app

ProductInvAppPrototype Create a single view project with three buttons Embed in a navigation controller – Select the view controller, then Navigator -> Embed In -> Navigation Controller Add one view controller to the storyboard with a label and an image view – Set label text to some product name (e.g., “Apple”) – Get an image file from the web representing the product (e.g., apple.jpeg), then drag onto “Supporting Files” section – Select the ImageView control, set the image file name

ProductInvAppPrototype Make two more copies of the view controller (that contains a label and an image) – Update these two copies so the three views represent different products (e.g., apple, orange and pomelo) Control-drag from each button to a view controller to create the corresponding segues – Select “push” Build and execute

ProductTest Create a single-view application with a single button – Add an action connection – Test code will be placed in the corresponding method Download the Product class (Product.h and Product.m) – Three properties: name, imgFileName, and stockLevel (the first two are of type NSString* the third is an int) – An initWith… method that initializes the properties – Methods to increase/decrease stockLevel: -(void) acceptDelivery:(int) qty -(void) releaseStock:(int) qty Test the Product class (test code provided in website)

ProductInventoryApp Follow instructions posted on the course website Summary – Two view controllers (controlled by a navigation controller), one for the main interface, the other for the product – Product class must be included in the project – Three products created by main view controller – Detail/product view controller has its display based on a product object

ProductInventoryApp: main view No properties defined in ViewController.h file No outlet connections No action connections (button click functionality handled through the segues) Three product variables declared outside of the methods within the ViewController.m file (these could have been properties but there is no reason to have the data available as properties) Product objects created within viewDidload method (initialization code executed when view appears) prepareForSegue method checks which button was pressed (which segue was used) and then sets the appropriate product to be set by the second view

ProductInventoryApp: product view Separate class (with superclass UIViewController) needs to be created and associated to this view controller Properties defined in.h file – outlet connections for all controls (except buttons) – One product object (to be set by the main view, but used by this view for display) Action connections (for the add and remove buttons) viewDidload contains code (in.m file) that displays details of the product object Code for the add/remove actions – Retrieve data from the text field and convert to int – Call methods to increase/decrease stock on the product object – Redisplay stock level

ProductInventoryApp