> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/GetMetaMap/metamap-ios-sdk/llms.txt
> Use this file to discover all available pages before exploring further.

# 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:

```objc theme={null}
#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:

```objc theme={null}
#import <MetaMapSDK/MetaMapSDK.h>
```

### 2. Declare Protocol Conformance

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

```objc theme={null}
@interface ViewController () <MetaMapButtonResultDelegate>

@property (nonatomic, strong) MetaMapButton *metaMapButton;

@end
```

### 3. Initialize MetaMapButton

In your `viewDidLoad` method, initialize the button:

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

### 4. Add Button Action

Connect the button to an action handler:

```objc theme={null}
[self.metaMapButton addTarget:self 
                      action:@selector(metaMapButtonAction:) 
            forControlEvents:UIControlEventTouchUpInside];
```

### 5. Configure Button Layout

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

```objc theme={null}
//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:

```objc theme={null}
[MetaMapButtonResult shared].delegate = self;
```

### 7. Launch Verification Flow

Implement the button action method to launch the verification flow:

```objc theme={null}
-(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

```objc theme={null}
#pragma mark - MetaMapButtonResultDelegate

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

### Cancellation Callback

```objc theme={null}
- (void)verificationCancelled {
    NSLog(@"Cancelled");
    // Handle cancellation
}
```

## Swift vs Objective-C Comparison

<Tabs>
  <Tab title="Swift">
    ```swift theme={null}
    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")
        }
    }
    ```
  </Tab>

  <Tab title="Objective-C">
    ```objc theme={null}
    #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
    ```
  </Tab>
</Tabs>

## 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:

```objc theme={null}
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](/ui/customization) options
* Explore [UIKit Integration](/ui/uikit-integration) for Swift
* See [SwiftUI Integration](/ui/swiftui-integration)