Find and replace value in Swift array of dictionaries

Question

How does one search an array of dictionaries for a match and replace that match with another dictionary?

Where lineItemsArray:Array is an array of dictionaries, I am looking to search the array elements for a match, return the index of that match, and then replace the dictionary at that index with a new one. Each dictionary in the array contains a recordId key which will be used for the search. Each recordId is unique and the search will always return a single result.

The new data that will be replacing the matching record is generated by web service and returned as a dictionary. (see below)

Here are my specific questions:

• How can the array of dictionaries be searched for match?
• How can the index path of that match be returned?
• What is the most efficient manner of replacing the dictionary at the matching index?

This is a sample of what the lineItemsArray looks like:

[{
    buyFromCompanyId = 1;
    buyFromJobId = 5276;
    comment = "";
    componentId = 2331;
    description = "";
    fulfillmentStatus = 0;
    globalJobId = 2470;
    inventoryItemId = 1824;
    isSerialized = 1;
    itemClass = 0;
    itemQty = 2;
    lineItemId = 50853;
    priceRecordId = 152693;
    productName = "Bose L1 Compact";
    qtyAlreadyPulled = 0;
    qtyRate1 = 3;
    qtyRate2 = "";
    qtyTotalStock = "";
    rate1 = "";
    rate2 = "";
    sellToCompanyId = 1;
}, {
    buyFromCompanyId = 1;
    buyFromJobId = 5276;
    comment = "";
    componentId = "";
    description = "";
    fulfillmentStatus = 0;
    globalJobId = 2470;
    inventoryItemId = 2010;
    isSerialized = "";
    itemClass = "";
    itemQty = 2;
    lineItemId = 50854;
    priceRecordId = 152695;
    productName = "C13 IEC Cable (Standard)";
    qtyAlreadyPulled = 0;
    qtyRate1 = "";
    qtyRate2 = "";
    qtyTotalStock = 23;

}, {
    buyFromCompanyId = 1;
    buyFromJobId = 5276;
    comment = "";
    componentId = "";
    description = "";
    fulfillmentStatus = 0;
    globalJobId = 2470;
    inventoryItemId = 2046;
    isSerialized = 1;
    itemClass = "";
    itemQty = 2;
    lineItemId = 50855;
    priceRecordId = 152697;
    productName = "L1 compact amp unit";
    qtyAlreadyPulled = 0;
    qtyRate1 = "";
    qtyRate2 = "";
    qtyTotalStock = 1;
}]

Answer 1

Unfortunately, Swift's global find method looks for a specific value instead of a value matching a predicate. You can define your own this way:

func find<C: CollectionType>(collection: C, predicate: (C.Generator.Element) -> Bool) -> C.Index? {
    for index in collection.startIndex ..< collection.endIndex {
        if predicate(collection[index]) {
            return index
        }
    }
    return nil
}

Then you can find the index of the dictionary in question and replace it directly:

let index = find(lineItemsArray) { $0["recordId"] == replaceKey }
if let index = index {
    lineItemsArray[index] = newDictionary
}