JSON File Reader

JsonHandler.swift

//
//  JsonHandler.swift
//
//  Created by Geoff Armstrong on 4/6/15.
//  Copyright (c) 2015 Geoff Armstrong. All rights reserved.
//

import Foundation
import UIKit

/**
    Class to handle the JSON file format of the peak listing
*/
class JsonHandler: NSObject {
    
    override init() {
        super.init()
        
    }
    
    /**
        Read data from a JSON file located in the main bundle
    
        :param: fileName Name of the json file
    
        :returns: NSDictionary if successful, nil otherwise
    */
    func jsonReadData(fileName: String) -> NSDictionary? {
        var error: NSError?
        var jsonArray: NSDictionary
        var dir: String?
        let dirs : [String]? = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true) as? [String]
        let bundle = NSBundle.mainBundle()
        
        dir = bundle.resourcePath
        
        if let path = dir?.stringByAppendingPathComponent(fileName) {
            
            if var input = NSInputStream(fileAtPath: path) {
                input.open()
                if input.hasBytesAvailable {
                    jsonArray = NSJSONSerialization.JSONObjectWithStream(input, options: NSJSONReadingOptions.MutableContainers, error: &error) as! NSDictionary
                    input.close()
                    //Success!
                    return jsonArray
                }
                else {
                    input.close()
                }
            }
        }
        
        //If all else fails...
        return nil
    }
    
    /**
    Read names from a JSON file located in the main bundle
    
    :param: fileName Name of the json file
    
    :returns: Array of String names
    */
    func readNames(fileName: String) -> [String] {
        //read JSON file
        
        var dict = jsonReadData(fileName)
        var name: String
        var names: [String] = []
        
        // Read Objects from System File
        if dict != nil {
            if let objects: NSArray = dict?["objects"] as? NSArray {
                for var i=0; i < objects.count; i++ {
                    if let objectDict: NSDictionary = objects[i] as? NSDictionary {
                        if let objectName = objectDict["name"] as? NSDictionary {
                            name = objectName as! String
                            names.append(name)
                        }
                    }
                }
            }
        }
        return names
    }
    
    /**
    Read peak dictionary from a JSON file located in the main bundle
    
    :param: fileName Name of the json file
    
    :returns: Array of NSDictionary if successful, nil otherwise
    */
    func readObjects(fileName: String) -> [NSDictionary]? {
        //read JSON file
        
        var dict = jsonReadData(fileName)
        var objects: [NSDictionary]?
        
        // Read Objects from System File
        if dict != nil {
            objects = dict!["objects"] as? [NSDictionary]
            if objects != nil {
                //Success!
                return objects
            }
        }
        //If all else fails...
        return nil
    }

}