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DOL Home > OPEN > Developer Community > iOS Federal SDK Sample

iOS Federal SDK Sample

Overview

This sample will provide the steps to create a simple iOS app that can consume DOL Data. Following these steps in order will allow your app to operate correctly. Download this project

You can also download a sample application that uses non-DOL APIs owned by other federal government agencies.

Create a New Project

From the file menu in Xcode select New -> New Project.

Create New Project in Xcode

Choose a template for your project. For this example we choose Master-Detail Application.

Select Template for Navigation based application

Provide a Product Name and Company Identifier and complete the New Project wizard.

Provide Product Name and Complete Wizard

Add Dependencies

The DOL Data SDK has some library dependencies we must add to the project. From the left pane choose the project (top level in the list), then from the center pane select the target. From the right pane choose the Build Phases tab.

Go to Build Phases and library dependencies

Expand the Link Binary with Libraries section. Click the + button to add the required frameworks. From the list that pops up choose:

  • libz.dylib
  • MobileCoreServices.framework
  • CFNetwork.framework
  • SystemConfiguration.framework
Tip: you can hold down the Command key to select multiple files.

Required Libraries are libz.dylib,MobileCoreServices.framework,CFNetwork.framework,SystemConfiguration.framework

Add SDK to Project

Add the SDK to your project. You can get it by either extracting the zipped SDK folder or by grabbing the Git repository. and drag-and-drop the DOLDataSDK folder to you project root (the first item on the left pane).

Add SDK to your project

From the option screen that pops up choose 'Copy items into destinations group folder' and 'Create groups for any added folders'.

Copy Items

Test that all the steps above have been done correctly by building the application. From the product menu, select Product -> Build.

Build Project

The status area at the top center should display that the build succeeded with no issues.

Build Successful

Locate Dataset Path

Each Dataset has a Dataset Location path that gives the URL that will be needed for the data request. This address is circled in red. (http://api.dol.gov/V1/Compliance/WHD)

Locate Dataset Path for DOl API Dataset Sample please use http://api.dol.gov/V1/Compliance/WHD

The data request will also need the location of the table you are pulling data from. The tables are listed under their datasets. This table's name is circled in red.

Table Name

Create the Master View Controller

Open MasterViewController.h.

  • We must modify the class so that it can respond to the GOVDataRequest delegate methods. Do this by adding the <GOVDataRequestDelegate> protocol to the class.
  • Add a NSArray ivar to store the results (*arrayOfResults).
  • Add a GOVDataRequest ivar. This is how we will make requests to the API.
  • Create properties for both ivars.
//	MasterViewController.h
//	SDK-Sample
//
 
#import 
#import "GOVDataRequest.h"
 
@interface MasterViewController : UITableViewController<GOVDataRequestDelegate> {
 
	// We will store the results here
	NSArray *arrayOfResults;
    NSDictionary *dictionaryOfResults;
 
	// API Request object
	GOVDataRequest *dataRequest;
}
 
@property(nonatomic)NSArray *arrayOfResults;
@property(nonatomic)GOVDataRequest *dataRequest;
@property (nonatomic)NSDictionary *dictionaryOfResults;


-(void)govDataRequest:(GOVDataRequest *)request didCompleteWithError:(NSString *)error;
-(void)govDataRequest:(GOVDataRequest *)request didCompleteWithResults:(NSArray *)resultsArray andResponseTime:(float)timeInMS;
-(void)govDataRequest:(GOVDataRequest *)request didCompleteWithDictionaryResults:(NSArray *)resultsDictionary andResponseTime:(float)timeInMS;
-(void)govDataRequest:(GOVDataRequest *)request didCompleteWithUnParsedResults:(NSString *)resultsString andResponseTime:(float)timeInMS;
 
@end


Open MasterViewController.m. Add #define constants for your API Key, Secret and Host. In a real production application, you may choose to store this information elsewhere (keychain, plist, etc).


#import "MasterViewController.h"
 
//Set API key information
#define API_KEY @"YOUR API KEY"
#define API_SECRET @"YOUR KEY SECRET"
#define API_HOST @"http://api.dol.gov"
#define API_URL @"/V1"


Synthesize the two ivars we created earlier.


@implementation MasterViewController
@synthesize dataRequest, arrayOfResults, dictionaryOfResults;


In this example we make the API call as soon as the app launches.

  • Create a GOVDataContext object. This object stores the API key information and URL.
  • Alloc init the GOVDataRequest ivar with the context object as parameter.
  • Set self as the delegate. This ensures that this class' GOVDataRequestDelegate methods are called when the API call completes.
  • Create an NSDictionary and store the arguments you want to send with the API call
  • Call callAPIMethod:withArguments:, providing the Dataset Location path, table name, and arguments dictionary. This will execute asyncronously.
-(void)viewDidLoad
{
	[super viewDidLoad];
 
	self.title = @"SDK Sample";
 
	//Create Context object
	//This object will store the URL and authorization information
	GOVDataContext *context = [[GOVDataContext alloc] initWithAPIKey:API_KEY Host:API_HOST SharedSecret:API_SECRET APIURL:API_URL];
 
	//Instantiate a new request
	dataRequest = [[GOVDataRequest alloc] initWithContext:context];
	//Set self as a delegate
	dataRequest.delegate = self;
	
	//Define the method that will be called
	NSString *method = @"Compliance/WHD/full";
 
	//Create a dictionary of arguments
	//Top 20 records; Selected 3 columns.
	NSDictionary *arguments = [NSDictionary dictionaryWithObjectsAndKeys:@"20", @"top", @"trade_nm,city_nm,st_cd", @"select", nil];
 
	//Set the timeout.  Set this higher for long-loading APIs
	int timeOut = 20;

	//Call API method with the arguments
	//didCompleteWithResults or didCompleteWithError delegate method will be called
	//when results or errors are returned
	[dataRequest callAPIMethod:method withArguments:arguments andTimeOut:timeOut];
}


Implement the GOVDataRequestDelegate methods didCompleteWithResults and didCompleteWithDictionaryResults:

  • Store results to the NSArray ivar.
  • Reload the table view.
#pragma mark GOVDataRequest delegate methods
-(void)govDataRequest:(GOVDataRequest *)request didCompleteWithResults:(NSArray *)resultsArray {
	NSLog(@"Got results");
 
	//Save results in our local array instance
	self.arrayOfResults = resultsArray;
 
	//Refresh the tableView
	[self.tableView reloadData];
}

-(void)govDataRequest:(GOVDataRequest *)request didCompleteWithDictionaryResults:(NSDictionary *)resultsDictionary {
    
    
    NSLog(@"Got a Dictionary");
	//Save results in our local dictionary instance
	self.dictionaryOfResults = resultsDictionary;
    //    NSLog(@"%@", self.dictionaryOfResults);
	//Refresh the tableView
	//[self.tableView reloadData];
}


Implement the govDataRequestDelegate method didCompleteWithError:. In this example we chose to just show the error in an UIAlertView.


-(void)GOVDataRequest:(GOVDataRequest *)request didCompleteWithError:(NSString *)error {
	UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:error delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];
 
	[alert show];
}

Complete the table view requirements:

  • Return the count for the results array in the numberOfRowsInSection: method
  • In the cellForRowAtIndexPath: method create an NSDictionary variable pointing to the object in the results NSArray whose index is equal to the row we are rendering.
  • Now we can set the cells text labels to any property of the NSDictionary.
  • The NSDictionary keys will be equal to the table column names.
//Customize the number of sections in the table view.
-(NSInteger)numberofSectionsInTableView:(UITableView *)tableView
{
	return 1;
}
 
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
	return [self.arrayOfResults count];
}
 
//Customize the appearance of table view cells.
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
	static NSString *CellIdentifier = @"Cell";
 
	UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
	if (cell == nil) {
		cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
	}
 
	//arrayOfResults is an array of NSDictionaries
	//Get the record
	NSDictionary *result = (NSDictionary *)[arrayOfResults objectAtIndex:indexPath.row];
 
	// Configure the cell.
 
	//Set the cell text to trade_nm
	cell.textLabel.text = (NSString *)[result objectForKey:@"trade_nm"];
	//Set the cell small text to "city, state"
	cell.detailTextLabel.text = [NSString stringWithFormat:@"%@, %@", (NSString *)[result objectForKey:@"city_nm"], (NSString *)[result objectForKey:@"st_cd"]];
 
	return cell;
}

-(void)dealloc
{
	// Thanks to ARC, nothing to do here
}


View DOL Data

Build and run the application, and you should see something like the following:


For DOL API datasets :

Completed App