Start 100DaysOfSwiftUI from 2020.Mar.18th.
Day 77: Milestone: Projects 13-15
done with 1 hours
Target: develop application with specified requirement
requirements
- use UIImagePickerController
- wrap controller into SwiftUI
- name selected photo with asking to user
- in SwiftUI, maybe with onDisappear()?
- save name and photo info
- show imported photo with its name in list, sorted by name
- use List
- photo detail view
- with NavigationView
- save all data
additional requirement
- use CoreData for saving
Steps
- Step1: define data model
- Step2: make main UI (list for named photo, sorted by name)
- Step3: wrap UIImagePickerController
- Step4: make detail view
Step1: define data model
Photo data + name info would be enough?
I guess we can save the path to the photo instead of photo data itself.(maybe wrong, but let’s see)
“NamedPhoto” is the entity in CoreData, which have 2 properties, “name”:String, “photoURL”:String.
As usual, let’s add some wrapped properties.
- add NamedPhoto in CoreData model
- generate code for NamedPhoto with setting “Manual” for coredata code generation
- add wrappedProperty to CoreData class
Step2: make main UI
- add environment var for getting MOC
- add fetch request as @State property in ContentView
- locate List and ForEach for iterate fetchresult (and show photo name and path for the moment)
Step3: wrap UIImagePickerController
Step3-1: add “+” button in NavigationView
as is…
Step3-2: wrap UIKit Controller
make ImagePickerController class which inherits UIViewControllerRepresentable and implement necessary controller.
Step3-3: integrate ImagePicker into main UI
in closure which will be called from “+” button, call ImagePicker, then create new entity with given data.
with checking UIImagePickerControllerDelegate, I found we can get NSURL for getting the photo data, so we can save this info into CoreData.
Add @State var “selectedPhoto” to ContentView then pass it to ImagePicker for getting the selected photo info from ImagePicker.
Add PresentationMode as environment for ImagePicker to close the dialog.
it is difficult to ask the name for the photo after selecting the photo in ImagePicker.
So I introduced sequenceView which will show 2 view sequentially.
step4: detail view
if we need to pass binding variable which comes from fetch result, I have no idea how to pass it at the moment.
But just passing exiting info from CoreData is no problem.
pitfall
EnvironemntObject will NOT be inherited to .sheet view. probably navigationView will make it share with child views, but not with Sheet…
codes
omitted. because it is too long…
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