I have a function in Swift 3 that gets metadata from MPMediaItems - in this case Podcasts.
The problem is that for some older Podcasts, when I retrieve a metadata Key instead of getting a String I get an NSTaggedPointerString which is essentially empty for my purposes - I can't compare it to a literal.
Here's an example of what I expect (String):
And here's what is giving me heartburn:
(I know the keys are not the same but that's not the issue)
How can I get the actual String value from the NSTaggedPointerString while still being able to get/use the more common String values that I also get?
Here's my function:
func getMeta(_ item: MPMediaItem)->String{
print("")
print("--------- GETMETA ---------")
let url = item.value(forProperty:MPMediaItemPropertyAssetURL) as? NSURL
let asset = AVURLAsset(url: url as! URL, options: nil)
var sTDES: String = ""
var sUSLT: String = ""
var sCOMM: String = ""
var sTIT3: String = ""
var sFinal: String = ""
for metadata in asset.metadata{
print("sKey:\(metadata.key)")
print("stringValue:\(metadata.stringValue)")
if let sKey = metadata.key{
// All of these comparisons fail if the Key is NSTaggedPointerString
if (sKey as! String == "TDS") || (sKey as! String == "TDES"){
if let xtdes = metadata.stringValue{
sTDES = xtdes
}
}else if (sKey as! String == "COM") || (sKey as! String == "COMM"){
if let xcomm = metadata.stringValue{
sCOMM = xcomm
}
}else if (sKey as! String == "USLT"){
if let xuslt = metadata.stringValue{
sUSLT = xuslt
}
}else if (sKey as! String == "TIT3") || (sKey as! String == "TT3"){
if let xtit3 = metadata.stringValue{
sTIT3 = xtit3
}
}
}
}
//Use the preferred value if available
if sTDES != ""{
sFinal = sTDES
}else if sCOMM != ""{
sFinal = sCOMM
}else if sUSLT != ""{
sFinal = sUSLT
}else if sTIT3 != ""{
sFinal = sTIT3
}else{
sFinal = " "
}
print("sFinal 1:\(sFinal)")
return sFinal
}
Another question is this: Why can I print the value of the key correctly, but not use it as a String for comparison?
//This prints correctly
print("** key string:\(metadata.key!)")
// this yields myKey = ""
myKey = metadata.key as! String
EDIT:
I'm making some small progress but still no solution. I've been tinkering with my code and am now trying this:
let metaArray = asset.metadata(forFormat: "org.id3")
for metadata in metaArray{
print("** metadata key:\(metadata.key!)")
let myKey = String(describing: metadata.key!) // The ! results in empty value, while keeping it results in Optional
print("** myKey:\(myKey)")
if myKey == "TDS"{
print("value:\(metadata.stringValue)")
}
}
It seems so strange that when I can see that myKey contains a value (pic 1) and I can print it, I am not able to remove the Optional() indicator. When I add the ! the value becomes empty and I cannot do a comparison - but I can still print it!! (pic 2)
pic 1
pic 2
EDIT 2: Finally a solution !
@alDiablo had a good suggestion but only got me part-way. I discovered through more research that part of the problem was a leading Null char "\0" in the returned string. Once I found that out, I could strip it off and do my comparison.
So here is the resulting code to handle the metadata key:
let realString = NSString(string: metadata.key! as! String) //There is probably a cleaner way to do this too
let sKey = realString.replacingOccurrences(of: "\0", with: "")
if (sKey == "TDS") || (sKey == "TDES"){
//Success!
}
