# Advanced Methods

To complete the functionalities, we provide the following methods:

1. [Enable and disable Biometric](#enable-and-disable-biometric)
2. [Check if Biometric or PIN are Enrolled](#check-if-methods-are-enrolled)
3. [Change PIN](#change-pin)

## Enable and Disable Biometric

Biometrics entries are **unique per device**. When the user disable their biometrics, their biometrics enrollment for that device will be deleted from the database. When they enable biometrics, they are essentially enrolling that device again for biometrics, and therefore **they will be prompted to verify the biometrics again.**

To do enable/disable biometrics, you have to **initialize Cotter's biometrics prompt** first using:

```java
Cotter.initBiometricSwitch(context, fragmentActivity, activity, cotterBiometricCallback);
```

Generally, `context`, `fragmentActivity`, and `activity` can be filled with `this` inside your activity.

**Here is a step-by-step guide on enabling and disabling Biometrics**

### 1. Create a Callback

This callback will called when biometric is enabled or disabled.

**cotterBiometricCallback**

```java
CotterBiometricCallback cotterBiometricCallback = new CotterBiometricCallback() {
  @Override
  public void onSuccess(boolean enrolled) {
      res.setText("Success" + enrolled);
      updateMethods();
  }

  @Override
  public void onCanceled() {
      res.setText("Canceled");
      updateMethods();
  }

  @Override
  public void onError(String s) {
      res.setText("Error" + s);
      updateMethods();
  }
};
```

**onSuccess**

`onSuccess` will be called when the biometric is *successfully* enabled or disabled.

* If the user successfully **disabled** biometrics, we will call `onSuccess(false)`. So `enrolled = false` here, because biometrics is no longer enrolled.
* If the user successfully **enabled** biometrics, we will call `onSuccess(true)`.

**onCanceled**

`onCanceled` will be called when the user try to enable biometrics, but they **canceled the biometric prompt** (dismissed the prompt).

**onError**

`onError` will be caleld when an error occur while enabling or disabling biometrics.

### 2. Initialize Cotter Biometric

{% hint style="warning" %}
You have to **initialize Cotter Biometric** before using it to **enable or disable**
{% endhint %}

```java
Cotter.initBiometricSwitch(Context ctx, FragmentActivity fragmentAct, Activity act, CotterBiometricCallback callback)
```

Example:

{% code title="MainActivity.java -> OnCreate" %}

```java
Cotter.initBiometricSwitch(this, this, this, cotterBiometricCallback);
```

{% endcode %}

### 3. Enable Biometric

Remember, you have to **initialize Cotter Biometric** first before calling this function.

```java
Cotter.biometricPrompt.enableBiometric();
```

### 4. Disable Biometric

Remember, you have to **initialize Cotter Biometric** first before calling this function.

```java
Cotter.biometricPrompt.disableBiometric();
```

### 5. Checking the Enrolled status of Biometric after enable/disable

You can check again if the biometric is correctly enabled/disabled using the function below:

```java
Cotter.methods.biometricEnrolled(new CotterMethodChecker() {
    @Override
    public void onCheck(boolean isEnrolled) {
        // Check if biometric enrolled
        bioEnrolled.setText("Biometric enrolled: " + isEnrolled);
    }
});
```

## Check if Methods are Enrolled

You can check if an authentication method is enrolled and available for a user.

### 1. Check if Biometric is available

```java
Cotter.methods.biometricAvailable(CotterMethodChecker callback)
```

This method is used to check if biometric is available on the user's device. You need to provide a callback of type `CotterMethodChecker` to handle the result.

Example:

```java
Cotter.methods.biometricAvailable(new CotterMethodChecker() {
    @Override
    public void onCheck(boolean b) {
        // Check if biometric available and enabled
        bioAvailable.setText("Biometric available: " + b);
    }
});
```

### 2. Check if Biometrics is enrolled in the current device

```java
Cotter.methods.biometricEnrolled(CotterMethodChecker callback)
```

This method is used to check if biometric is enrolled. You need to provide a callback of type `CotterMethodChecker` to handle the result.

Example:

```java
Cotter.methods.biometricEnrolled(new CotterMethodChecker() {
    @Override
    public void onCheck(boolean isEnrolled) {
        // Check if biometric enrolled
        bioEnrolled.setText("Biometric enrolled: " + isEnrolled);
    }
});
```

### 3. Check if Pin is enrolled

```java
Cotter.methods.pinEnrolled(CotterMethodChecker callback)
```

This method is used to check if pin is enrolled. You need to provide a callback of type `CotterMethodChecker` to handle the result.

Example:

```java
Cotter.methods.pinEnrolled(new CotterMethodChecker() {
    @Override
    public void onCheck(boolean b) {
        // Check if biometric available and enabled
        pinEnrolled.setText("Pin Enrolled: " + b);
    }
});
```

## **Change Pin**

Starting the `PinChange` flow is exactly the same as starting the `PinEnrollment` flow.

```
Cotter.PinChange.startFlow(view, CallBack.class, "EVENT TAG");
```

Example:

```
// Inside your app, use a button onClick that calls
// openPinChange to start the flow
public void openPinChange(View view) {
    Cotter.PinChange.startFlow(view, Dashboard.class, "PIN_CHANGE");
}
```