Objective-C Integration

Complete guide to integrating MetaMap SDK with Objective-C applications

Overview

This guide shows you how to integrate the MetaMap SDK into your Objective-C-based iOS application using the MetaMapButton component.

Prerequisites

• MetaMap SDK installed via CocoaPods
• iOS 13.0 or later
• Xcode with Objective-C support

Implementation

Complete Objective-C Example

Here’s a complete implementation of MetaMap verification in Objective-C:

#import "ViewController.h"
#import <MetaMapSDK/MetaMapSDK.h>

@interface ViewController () <MetaMapButtonResultDelegate>

@property (nonatomic, strong) MetaMapButton *metaMapButton;

@end

@implementation ViewController

  - (void)viewDidLoad {
      [super viewDidLoad];

      //init button
      self.metaMapButton = [[MetaMapButton alloc] init];

      //add action to yours button
        [self.metaMapButton addTarget:self action:@selector(metaMapButtonAction:) forControlEvents:UIControlEventTouchUpInside];

      //set view of button
      self.metaMapButton.frame = CGRectMake(20, self.view.frame.size.height/2 - 25, self.view.frame.size.width - 40, 50);
      self.metaMapButton.center = self.view.center;

       //add button to yours view
      [self.view addSubview:self.metaMapButton];

      //set delegate to get result
      [MetaMapButtonResult shared].delegate = self;
  }

  //add showMetaMapFlow function with YOURS parameters
  -(void)metaMapButtonAction:(UIButton *) sender{
      [MetaMap.shared showMetaMapFlowWithClientId:@"YOUR_CLIENT_ID" flowId:@"YOUR_FLOW_ID"  metadata:@{@"key1":@"value"}];
}

#pragma mark - MetaMapButtonResultDelegate

  -(void)verificationSuccessWithIdentityId:(NSString *)identityId, verificationID(NSString *) {
      NSLog(@"Success: $@", identityId);
  }

  - (void)verificationCancelled {
      NSLog(@"Cancelled");
  }

@end;

Step-by-Step Implementation

1. Import MetaMap SDK

Add the import statement to your view controller header or implementation file:

#import <MetaMapSDK/MetaMapSDK.h>

2. Declare Protocol Conformance

In your interface, declare that your view controller conforms to MetaMapButtonResultDelegate:

@interface ViewController () <MetaMapButtonResultDelegate>

@property (nonatomic, strong) MetaMapButton *metaMapButton;

@end

3. Initialize MetaMapButton

In your viewDidLoad method, initialize the button:

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //init button
    self.metaMapButton = [[MetaMapButton alloc] init];
}

4. Add Button Action

Connect the button to an action handler:

[self.metaMapButton addTarget:self 
                      action:@selector(metaMapButtonAction:) 
            forControlEvents:UIControlEventTouchUpInside];

5. Configure Button Layout

Set the button’s frame and add it to your view:

//set view of button
self.metaMapButton.frame = CGRectMake(20, 
                                      self.view.frame.size.height/2 - 25, 
                                      self.view.frame.size.width - 40, 
                                      50);
self.metaMapButton.center = self.view.center;

//add button to yours view
[self.view addSubview:self.metaMapButton];

6. Set Delegate

Assign the delegate to receive verification results:

[MetaMapButtonResult shared].delegate = self;

7. Launch Verification Flow

Implement the button action method to launch the verification flow:

-(void)metaMapButtonAction:(UIButton *)sender {
    [MetaMap.shared showMetaMapFlowWithClientId:@"YOUR_CLIENT_ID" 
                                         flowId:@"YOUR_FLOW_ID" 
                                       metadata:@{@"key1":@"value"}];
}

Handling Results

Implement the MetaMapButtonResultDelegate protocol methods to handle verification results:

Success Callback

#pragma mark - MetaMapButtonResultDelegate

-(void)verificationSuccessWithIdentityId:(NSString *)identityId 
                          verificationID:(NSString *)verificationID {
    NSLog(@"Success: %@", identityId);
    // Handle successful verification
}

Cancellation Callback

- (void)verificationCancelled {
    NSLog(@"Cancelled");
    // Handle cancellation
}

Swift vs Objective-C Comparison

Swift

import MetaMapSDK

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        setupMetaMapButton()
    }
    
    private func setupMetaMapButton() {
        let metaMapButton = MetaMapButton()
        metaMapButton.addTarget(self, 
                               action: #selector(metaMapButtonAction), 
                               for: .touchUpInside)
        metaMapButton.frame = CGRect(x: 20, 
                                    y: view.frame.size.height/2 - 50, 
                                    width: view.frame.size.width - 40, 
                                    height: 50)
        view.addSubview(metaMapButton)
        MetaMapButtonResult.shared.delegate = self
    }
    
    @objc private func metaMapButtonAction() {
        MetaMap.shared.showMetaMapFlow(
            clientId: "YOUR_CLIENT_ID",
            flowId: "YOUR_FLOW_ID",
            metadata: ["key1": "value1"]
        )
    }
}

extension ViewController: MetaMapButtonResultDelegate {
    func verificationSuccess(identityId: String?, verificationID: String?) {
        print("Success: \(identityId ?? "")")
    }
    
    func verificationCancelled() {
        print("Cancelled")
    }
}

Objective-C

#import <MetaMapSDK/MetaMapSDK.h>

@interface ViewController () <MetaMapButtonResultDelegate>
@property (nonatomic, strong) MetaMapButton *metaMapButton;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.metaMapButton = [[MetaMapButton alloc] init];
    [self.metaMapButton addTarget:self 
                          action:@selector(metaMapButtonAction:) 
                forControlEvents:UIControlEventTouchUpInside];
    
    self.metaMapButton.frame = CGRectMake(20, 
                                          self.view.frame.size.height/2 - 25, 
                                          self.view.frame.size.width - 40, 
                                          50);
    self.metaMapButton.center = self.view.center;
    [self.view addSubview:self.metaMapButton];
    
    [MetaMapButtonResult shared].delegate = self;
}

-(void)metaMapButtonAction:(UIButton *)sender {
    [MetaMap.shared showMetaMapFlowWithClientId:@"YOUR_CLIENT_ID" 
                                         flowId:@"YOUR_FLOW_ID" 
                                       metadata:@{@"key1":@"value"}];
}

#pragma mark - MetaMapButtonResultDelegate

-(void)verificationSuccessWithIdentityId:(NSString *)identityId 
                          verificationID:(NSString *)verificationID {
    NSLog(@"Success: %@", identityId);
}

- (void)verificationCancelled {
    NSLog(@"Cancelled");
}

@end

Parameters

showMetaMapFlowWithClientId Parameters

Parameter	Type	Required	Description
clientId	NSString*	Yes	Your MetaMap client ID
flowId	NSString*	Yes	The verification flow ID
metadata	NSDictionary*	No	Additional metadata and customization options

Metadata Dictionary

The metadata parameter accepts an NSDictionary with optional customization values:

NSDictionary *metadata = @{
    @"key1": @"value1",
    @"key2": @"value2",
    @"buttonColor": @"#FF5733",
    @"buttonTextColor": @"#FFFFFF",
    @"fixedLanguage": @"es"
};

[MetaMap.shared showMetaMapFlowWithClientId:@"YOUR_CLIENT_ID" 
                                     flowId:@"YOUR_FLOW_ID" 
                                   metadata:metadata];

Best Practices

1. Memory Management: Use strong property attribute for the metaMapButton property
2. Delegate Lifecycle: Set the delegate in viewDidLoad and clear it in dealloc if needed
3. Button Positioning: Consider using Auto Layout constraints instead of manual frame calculations
4. Error Handling: Always implement both delegate methods to handle success and cancellation

Next Steps

• Learn about UI Customization options
• Explore UIKit Integration for Swift
• See SwiftUI Integration