After you call the pay API, a different type of payment continuation URLs is returned in the API response depending on the payment method used to proceed with the payment process. This article provides you with best practices for using payment continuation URLs corresponding to different client types. For more details about payment continuation URLs returned for each payment method, see the URLs returned for some payment methods.

Types of payment continuation URLs

For different merchant client types (Web, WAP, App), different payment methods return some or all of the following three types of payment continuation URLs in the response of the pay API to proceed with the payment process.

Notes:

• When using the above links to initiate a payment, an exception might occur during the redirection if the buyer does not have the payment method app installed. Handle the exception properly if any.
• The URLs returned by some payment methods cannot be used multiple times. If the payment page failed to be invoked using the URL, we recommend that you use a new paymentRequestId value to obtain the URL and reinvoke the payment page.
• In addition to the URL redirection method, the pay API response might include the orderCodeForm field for certain payment methods. This field value contains QR code or payment code information, which can be used to display the code on your website. This allows for a seamless payment process within your website. For more information on this solution, see Pre-front solution.

Web

This section provides information about how to proceed with the payment continuation URL in the terminalType of WEB. For payments on a computer website, the response of the pay API contains the payment continuation URL identified as normalUrl.

Open the URL

After obtaining the normalUrl value, you need to redirect the buyer to the payment page using the payment continuation URL. We recommend that you open the URL in a new tab to guide the buyer to complete the payment. The code for opening a new page is as follows:

if (serverResponse.normalUrl != null) {
    window.open(serverResponse.normalUrl, '_blank');
}

User experience

The payment page rendered using normalUrl can be a QR code-scanning page or a login page. The following diagram shows the payment process in the two cases:

WAP

This section provides information about how to proceed with the payment continuation URL in the terminalType of WAP. For payments on a mobile website, the response of the pay API might contain one or more of the following payment continuation URLs:

• normalUrl
• applinkUrl
• schemeUrl

Choose a URL

If the pay API response only contains one of the three URLs, use the received URL directly as the redirection link. If you receive multiple URLs, we recommend that you choose the URL based on the following instruction:

• For iOS system: prioritize using applinkUrl, then schemeUrl, and finally normalUrl.
• For Android system: prioritize using schemeUrl, then applinkUrl, and finally normalUrl.

Open the URL

To open the URL using JavaScript's redirection method, use the following code:

window.location.href = URL;

User Experience

APP

This section provides information about how to proceed with the payment continuation URL in the terminalType of APP. For payments on a mobile application, the response of the pay API might contain one or more of the following payment continuation URLs:

• normalUrl
• applinkUrl
• schemeUrl

Note: For payments on a mobile application, in addition to the URL parameters used for redirection mentioned above, the response of the pay API also contains the appIdentifier parameter. This parameter is the package name of the corresponding payment method app and is used to determine whether the payment method app is installed for app payment. It can also be used to avoid disambiguation dialogs on Android.

Choose a URL

If the pay API response only contains one of the three URLs, use the received URL directly as the redirection link. If you receive multiple URLs, we recommend that you choose the URL based on the following instruction:

• For iOS system: prioritize using applinkUrl, then schemeUrl, and finally normalUrl.
• For Android system: prioritize using schemeUrl, then applinkUrl, and finally normalUrl.

Open a URL

For Android and iOS, open the payment continuation URL by using one of the following redirection methods:

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 10.0) {
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:Url] options:@{} completionHandler:nil];
}else{ 
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:Url]];
}

// Initialize webview configuration
WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc]init];
// Initialize webView 
WKWebView *webView = [[WKWebView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height) configuration:configuration];
webView.navigationDelegate = self;
//Load the payment method URL
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:Url]]];
[self.view addSubview:self.webView];

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{
    // WKWebView intercepts the redirection by default. Enable the redirection in the following ways. 
    // Operations such as opening Safari
    NSURL *url = navigationAction.request.URL;
    NSString *absoluteString = url.absoluteString;
    NSString *scheme = url.baseURL.scheme;

    DLog(@"navigationAction.request.URL.absoluteString=====> %@", absoluteString);
    if ([absoluteString isEqualToString:@"about:blank"]) {
        decisionHandler(WKNavigationActionPolicyCancel);
    }
    if (!([absoluteString containsString:@"https://"] || [absoluteString containsString:@"http://"])) {
        if ([absoluteString containsString:@"://"]) {
            NSString *urlHeader =  [absoluteString componentsSeparatedByString:@"://"][0];
            [MBProgressHUD showAutoMessage:[NSString stringWithFormat:@"Scheme\n%@://",urlHeader] toView:self.view];
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                [self openAppWithUrlStr:navigationAction.request.URL];
                decisionHandler(WKNavigationActionPolicyAllow);
            });
        }
    } else {
        decisionHandler(WKNavigationActionPolicyAllow);
    }
}

[self.wkWebView evaluateJavaScript:bridge completionHandler:nil];

SFSafariViewController *safariVC = [[SFSafariViewController alloc] initWithURL:Url entersReaderIfAvailable:NO];
safariVC.delegate = self;
[self.navigationController presentViewController:safariVC animated:YES completion:nil];

NSString *walletSchemeUrl = @"gcash://";

if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:walletSchemeUrl]]){
    // The payment method app is installed. Open the app directly.
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:Url] options:@{} completionHandler:nil];
    
    return YES;
} else {
    // The payment method app is not installed. We recommend that you load the mobile website in WebView.
    SFSafariViewController *safariVC = [[SFSafariViewController alloc] initWithURL:Url entersReaderIfAvailable:NO];
    safariVC.delegate = self;
    [self.navigationController presentViewController:safariVC animated:YES completion:nil];
    
    return NO;
}

try {
    Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(Url));
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
    // use the startActivity function to redirect to the wallet app 
    startActivity(intent);
} catch (Exception e) {
    e.printStackTrace();
}

WebView webView = findViewById(R.id.webview);
//Set webview
webView.setWebViewClient(new WebViewClient() {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
        view.loadUrl(request.getUrl().toString());
        return super.shouldOverrideUrlLoading(view, request);
    }});

WebSettings webSettings = webView.getSettings();
//Enable javascript
webSettings.setJavaScriptEnabled(true);
//Enable scaling
webSettings.setSupportZoom(true);
//Enable scaling controls (buttons)
webSettings.setBuiltInZoomControls(true);
//Webview has two cache modes. Cache is not used here.
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
//Allow JavaScript to open a new tab (false by default)
webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
//Allow JavaScript to load local storage
webSettings.setDomStorageEnabled(true);
//WAP cache size (settings are not needed)
//webSettings.setAppCacheMaxSize(1024 * 1024 * 8);
//WAP cache path
String absolutePath = getApplicationContext().getCacheDir().getAbsolutePath();
//WAP cache size
webSettings.setAppCachePath(absolutePath);
//Set whether to allow WebView to access files (true by default)
webSettings.setAllowFileAccess(true);
//Allow WAP cache to be saved
webSettings.setAppCacheEnabled(true);
//In preview mode, if the page width exceeds the WebView display, scale down the page to fit WebView (false by default)
webSettings.setLoadWithOverviewMode(true);
//Support the viewport HTML meta tag
webSettings.setUseWideViewPort(true);
//Load the payment method URL
webView.loadUrl(Url);

@Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
    if (request.getUrl().toString().startsWith("http")) {
        view.loadUrl(request.getUrl().toString());
        return super.shouldOverrideUrlLoading(view, request);
    } else {
        view.onPause();
        view.stopLoading();
        try {
          Intent intent = Intent.parseUri(uri, Intent.URI_INTENT_SCHEME);
          intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
          view.getContext().startActivity(intent);
        } catch (URISyntaxException e) {
          //Alert that this scheme is not supported
        }
        return false;
    }
}

@JavascriptInterface
    public void openActivity(String url) {
        //Add the code if needed
        try {
        Intent intent = Intent.parseUri(uri, Intent.URI_INTENT_SCHEME);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    } catch (Exception e) {
        Toast.makeText(context, "App not installed", Toast.LENGTH_SHORT).show();
    }
}

mWebView.addJavascriptInterface(this, "bridge");

window.bridge.openActivity("Url");

dependencies {
    ...
    implementation "androidx.browser:browser:1.4.0"
}

// Use CustomTabsIntent.Builder to configure CustomTabsIntent.
// Use CustomTabsIntent.Builder.build() to create CustomTabsIntent
// Use CustomTabsIntent.launchUrl() to launch the URL

CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder();
CustomTabsIntent customTabsIntent = builder.build();
customTabsIntent.launchUrl(this, Uri.parse(url));

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:tools="http://schemas.android.com/tools"
          package="com.llw.scandemo">
  
  ...
  <queries>
    <package android:name="th.co.truemoney.wallet" />
    <package android:name="com.eg.android.AlipayGphone" />
    <package android:name="my.com.tngdigital.ewallet" />
    ...
  </queries>
  ...
  
</manifest>

String Url = "applinkUrl/schemeUrl";
try {
    Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(Url));
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    intent.setPackage("my.com.tngdigital.ewallet");
    // Determine whether the payment method app is installed
    PackageManager packageManager = MainActivity.this.getPackageManager();
    List<ResolveInfo> activities = packageManager.queryIntentActivities(intent, 0);
    
    if (activities.size() <= 0) {
        // The payment method app is not installed. We recommend that you open the mobile website URL in WebView.

        intent = new Intent(MainActivity.this, WebviewActivity.class);
        intent.setData(Uri.parse(Url));
        startActivity(intent);
    } else {
        
        // The payment method app is installed. Open the payment method app directly.
        startActivity(intent);
    }
} catch (Exception e) {
    // Handle exceptions
    e.printStackTrace();
}

Pros and cons of each redirection method

Each redirection method has its pros and cons. We recommend that you choose the most suitable redirection method based on the operation system and integration scenario.

User experience of each redirection method

The payment processes corresponding to different opening methods of the payment continuation URL are as follows:

Best practice for configuring redirection methods

We recommend that you fix the configuration for opening the payment continuation URL based on different payment methods, or route based on the payment method, device environment, and URL type. The following figure shows an example of fixed configuration based on different payment methods:

For each payment method, we recommend that you determine the method of opening the payment continuation URL according to the following logic:

FAQ: What is a disambiguation dialog box

Android App Link requests authentication from Google servers when installing the app. If authentication fails, the Android App Link will become invalid, and a disambiguation dialog box will appear when the buyer tries to open the app through such a link. The buyer needs to manually select how to open the link.

Prevent the appearance of a disambiguation dialog box

When a disambiguation dialog box appears, the buyer needs to manually select the way to open the application, which affects the payment success rate. Therefore, you need to prevent the appearance of a disambiguation dialog box by taking the following action as needed:

• If the buyer has installed the payment method app, specify the package name of the payment method and open the URL of the payment method.
• If the buyer has not installed the payment method app, use the sample code below to open the URL.

Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(applinkUrl));
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
//Specify the package name of the payment method
intent.setPackage(walletPackageName);
PackageManager packageManager = MainActivity.this.getPackageManager();
//Check whether there is an app that supports opening this link.
List<ResolveInfo> activities = packageManager.queryIntentActivities(intent, 0);
if (activities.size() <= 0) {
   //The payment method app is not installed. Initialize the Intent object. This link will be opened by the default Android method.
   intent = new Intent(Intent.ACTION_VIEW, Uri.parse(applinkUrl));
   intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
     startActivity(intent);
} else {
  //The payment method app is installed. Specify the package name of the payment method and open the payment method URL. The disambiguation dialog box will not appear.
     startActivity(intent);
}

Notes:

The packageName values of some payment methods are shown as follows:

• AlipayHK: hk.alipay.wallet
• GCash: com.globe.gcash.android
• TrueMoney: th.co.truemoney.wallet
• Kakao Pay: com.kakao.talk
• Touch'n Go eWallet: my.com.tngdigital.ewallet
• DANA: id.dana