ForEach on a dictionary - ios

Question

I need my app to display a table of data. The data looks like ["body": Optional("Go Shopping"), "isDeleted": Optional(false), "_id": Optional("63333b1600ce507b0097e3b3"), "isCompleted": Optional(false)] The column headers for the table would be the keys body, isDeleted, isCompleted, _id. I will have multiple instances of this data that will have the same keys, but different values. I will need to display the values for each data instance under the respective header and each row will belong to one data instance.
Example:
I'm struggling because the only way I can think of doing this is with a dictionary, but run into a lot of problems when using a dictionary in the View.
*** Important Note:
The app allows a user to select a certain collection and then the app will load all the data for that collection. Each collection has different keys in its data, so I cannot create a specific struct since I won't actually know the keys/values in the data. The model will have to be dynamic in the sense that I don't know what key/value types will be used in each collection and the table will need to redraw when a different collection is selected.
What I Tried
A document class that would hold a 'value: [String: Any?]` the string would be the key and the Any is the value from the data instance
class Document{
let value: [String:Any?]
init(value:[String:Any?]) {
self.value = value
}
}
in my ViewModel I have a call to a database that uses the selected collection name to return an array of all the documents from that collection. I loop through the array and create a Document obj with the value of the Document looking like ["body": Optional("Go Shopping"), "isDeleted": Optional(false), "_id": Optional("63333b1600ce507b0097e3b3"), "isCompleted": Optional(false)] and I add each Document to an array of Document's
class DocumentsViewModel : ObservableObject {
#Published var docKeys: [String]?
#Published var docsList: [Document]?
func getDocs() {
... //Database call to get docs from collection
for doc in docs {
// add doc keys to array (used for table header)
self.docKeys = doc.value.keys.map{$0}
self.docsList?.append(Document(value: doc.value))
}
Then in my View I tried to first display a header from the docKeys and then use that key to loop through the array of [Document] and access the value var and use the key to get the correct value to display under the header for that document
var body: some View {
Text(viewModel.collectionName)
HStack {
ForEach(viewModel.docKeys ?? [], id: \.description) {key in
Text(key.name)
VStack {
ForEach(viewModel.docsList ?? [], id: \.value) { doc in
Text(doc.value[property.name])
}
}
}
}
}
After doing research I understand why I can't ForEach over an unsorted dictionary.
I will accept any help/guidance on how I can display this table. Also, if there is any other suggestions besides using a dictionary? THANK YOU!
**Update
I was able to get it working with an ordered collection
class Document : Hashable, Equatable{
static func == (lhs: Document, rhs: Document) -> Bool {
lhs.id.description == rhs.id.description
}
let id: String
let value: OrderedDictionary<String,Any?>
init(id: String, value: OrderedDictionary<String,Any?>) {
self.id = id
self.value = value
}
func hash(into hasher: inout Hasher) {
hasher.combine(id)
}
}
Since it is ordered this allowed me to iterate of the dictionary in the View

Answer 1

Just a a few hints:
If you need "dictionary with order" you can try to use a Key-ValuePairs object which is essentially an array of tuples with labels key and value
let values: KeyValuePairs = ["key1": "value1", "key2": "value2"]
when you print this to the console you'll realize that this is just a tuple!
print(values[0]) will display (key: "key1", value: "value1")
please take a look at OrderedDictionary from The Swift Collections https://www.kodeco.com/24803770-getting-started-with-the-swift-collections-package
have you consider to use an array of simple structs instead?
struct Document {
let body: String?
let isDeleted: Bool?
let id: String?
let isCompleted: Bool?
...
}