Swift replace key value in array of dictionaries with nested dictionaries - swift

Question

I have swift dictionary [String: Any] which I store in UserDefauls as an array [[String: Any]]
what I want to do is replace key: value with another one, e.g. "id": "x:coredataid"with"id": "server id"
I need to loop through array first and then through all key values. Is there any elegant solution for this purposes?
If not how then simple iterate through all key values and all nested levels in dictionary?
I have this code: for (key, value) in params
but it's only for top level keys.
Let me explain more in details. As you see I have phases key which an array. Also each phase contains day key which also an array.
So I don't care actually about key naming, phases it or days whether, what I want is to iterate all of key, values from provided [String: Any] dictionary and check if key contains a value which equal provided string.
As you see currently workoutId equals: <x-coredata://C3C82F5A-8709-4EDC-8AE5-C23C65F220D5/WorkoutEntity/t072831FB-8F5C-4589-85CB-6D084671C097815> I underscore it with red line.
So I want to loop a dictionary to catch this key workoutId and check if this equal <x-coredata://C3C82F5A-8709-4EDC-8AE5-C23C65F220D5/WorkoutEntity/t072831FB-8F5C-4589-85CB-6D084671C097815>
One more time I don't care about workoutId name, key can be actually named as exerciseId or id never mind. I just want to find a value <x-coredata://C3C82F5A-8709-4EDC-8AE5-C23C65F220D5/WorkoutEntity/t072831FB-8F5C-4589-85CB-6D084671C097815> in my entire dictionary and if there are lot of them replace all of them.
The reason why I need it is connected to identifier I store localy which are equals to CoreData identifiers as you my noticed. But when I modified my CoreData records with new identifiers returned from server I want to replace my UserDefaults off-line requests store with new ids.
I've added also modification to this code:
func update(_ dict: [String: Any], set serverId: Any, for localId: String) -> [String: Any] {
var newDict = dict
for (k, v) in newDict {
if let mobileLocalId = v as? String {
if mobileLocalId == localId {
newDict[k] = serverId
} else { newDict[k] = v }
} else if let subDict = v as? [String: Any] {
newDict[k] = update(subDict, set: serverId, for: localId)
} else if let dictionaries = v as? [[String: Any]] {
for dictionary in dictionaries {
newDict[k] = update(dictionary, set: serverId, for: localId)
}
}
}
return newDict
}
but it somehow drop days for me and newDict now looks like this:
(lldb) po newDict
▿ 2 elements
▿ 0 : 2 elements
- key : "position"
- value : 0
▿ 1 : 2 elements
- key : "workoutId"
- value : "5d51723b3faceb53f9d2d5ed"
where actully I susscefully changed identifiers, but now all other key pairs from above example are missed.

Answer 1

Here is a solution with a recursive function that replaces all values for a given key.
func update(_ dict: [String: Any], set value: Any, for key: String) -> [String: Any] {
var newDict = dict
for (k, v) in newDict {
if k == key {
newDict[k] = value
} else if let subDict = v as? [String: Any] {
newDict[k] = update(subDict, set: value, for: key)
} else if let subArray = v as? [[String: Any]] {
var newArray = [[String: Any]]()
for item in subArray {
newArray.append(update(item, set: value, for: key))
}
newDict[k] = newArray
}
}
return newDict
}
Note that it doesn't check what type the existing value is but directly replaces it with the new value. Also the code assumes the only types of nested arrays are arrays of dictionaries.
For the array this function can be used with map
let out = data.map { update($0, set: "newValue", for: "id")}

Answer 2

This recursive function will iterate through all key values:
func iterateThroughAllKeyValues<Key: Hashable, Value>(of dictionary: Dictionary<Key, Value>, execute execution: ((Key, Value))->()) {
for element in dictionary {
if let dictionary = element.value as? [Key: Value] {
iterateThroughAllKeyValues(of: dictionary, execute: execution)
} else {
execution(element)
}
}
}
Also you can achieve calling execution on the main node of any nested dictionary with a little bit of change.
And this is the extension mode:
extension Dictionary {
func iterateThroughAllKeyValues(execute execution: ((Key, Value))->()) {
for element in self {
if let dictionary = element.value as? [Key: Value] {
dictionary.iterateThroughAllKeyValues(execute: execution)
} else {
execution(element)
}
}
}
}
Note: Careful about the order
Usage Example:
let dictionary: [String: Any] = [
"id0": "value0",
"nested": ["id1": "value1"],
"nestedNested": ["id2": "value2",
"nested": ["id3": "value3"]]
]
dictionary.iterateThroughAllKeyValues { (key, value) in
print("key:", key, "Value:", value)
}
Output:
key: id0 Value: value0
key: id1 Value: value1
key: id3 Value: value3
key: id2 Value: value2