Swift解析含重复标识符的JSON：获取挪威能源API指定数据

Hey there! I see the problem you're running into — the API's response structure has multiple ProdConsOverViewModelItem entries under HydroData, and your current code is trying to access it as a single object instead of an array. Let's fix that step by step.

The Root Cause #

Your original code assumes ProdConsOverViewModelItem is a single dictionary, but in reality, it's an array of dictionaries (since there are multiple identical nodes in the response). SwiftyJSON can't find the value key under a non-existent single item, hence the "parse fail" message.

Updated Parsing Code #

Replace your updateEnergyData function with this version, which handles the array correctly and searches for the specific item you need:

func updateEnergyData(json : JSON){
    // First, extract the array of HydroData items
    guard let hydroItems = json["ProductionConsumptionOverviewViewModel"]["HydroData"]["ProdConsOverViewModelItem"].array else {
        print("No hydro items found or invalid response structure")
        return
    }
    
    // Search the array for the item with your target titleTranslationId
    if let targetHydroItem = hydroItems.first(where: { item in
        item["titleTranslationId"].string == "ProductionConsumption.HydroSEDesc"
    }) {
        // Extract the value if it exists
        if let hydroSEValue = targetHydroItem["value"].double {
            print("Hydro SE Production/Consumption Value: \(hydroSEValue)")
        } else {
            print("Could not extract numeric value from target item")
        }
    } else {
        print("Item with titleTranslationId 'ProductionConsumption.HydroSEDesc' not found")
    }
}

Key Changes Explained #

• Guard for the array: We first make sure we can access the array of ProdConsOverViewModelItem entries. If this fails, we get a clear error message instead of silent failure.
• Search with first(where:): This iterates through the array and returns the first item where the titleTranslationId matches your target string.
• Safe value extraction: We check that the value is a double before using it, avoiding unexpected crashes or nil values.

Quick Debug Tip #

If you're still having trouble, add a print statement to inspect the array structure:

print("Hydro Items: \(hydroItems)")

This will let you verify that the titleTranslationId keys match exactly (case sensitivity matters!) and that the value field is indeed a numeric type.

内容的提问来源于stack exchange，提问作者Nisse82