How to append data to decodedData in Swift

Asked Jul 21 '18 at 19:59

Active Jul 21 '18 at 21:06

Viewed 81 times

I followed this tutorial, Save custom objects into NSUserDefaults to figure out how to save data with classes. My problem is that I need to update this data without overriding the old data. I am currently trying

let data = [ToDo(name: cardTitle.text!, length: 7, startDate: Date(), itemArray: subarray)]
let newData = decodedData.append(data)
let encodedData: Data = NSKeyedArchiver.archivedData(withRootObject: newData)

defaults.set(encodedData, forKey: "data")
defaults.synchronize()

but this returns an error because trying to append data to decodeData returns () and I have no idea how to fix it. The only thing that works is

let data = [decodeData[0], ToDo(name: cardTitle.text!, length: 7, startDate: Date(), itemArray: subarray)]

but this won't work because I need to use more than just the data at index 0.

Has anyone run into this before? Any thoughts?

edited Jul 21 '18 at 21:06

rmaddy

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asked Jul 21 '18 at 19:59

Zavier Miller

Read the data, unarchive it, append the ToDo, archive it, save the data. – vadian Jul 21 '18 at 20:05
What's the difference between that and what I'm doing? – Zavier Miller Jul 21 '18 at 20:12
`append` hasn't a return value: `decodedData.append(data)` `let encodedData: Data = NSKeyedArchiver.archivedData(withRootObject: decodedData)` – vadian Jul 21 '18 at 20:14
OH thank you! I was used to python where u didn't want to edit the original array, thank you so much! – Zavier Miller Jul 21 '18 at 20:37
Unrelated but get rid of that unnecessary call to `synchronize`. – rmaddy Jul 21 '18 at 21:06

How to append data to decodedData in Swift

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