DataWedge Intent Example

Overview

The DataWedge service comes preinstalled on all Zebra mobile devices running Android and can add scanning capabilities to virtually any app on the device. This example describes a simplified application that demonstrates how to use DataWedge to receive scanned barcode data through an Android intent.

In essence, the process boils down to this:

1. Deploy the target Android app (on which to enable scanning) to a Zebra device.
2. Launch DataWedge on the device.
3. Configure DataWedge INPUT (barcode scanner) and OUTPUT (Intent).
4. Optional: Create a Profile to associate with the target app. If no Profile is created and assigned, DataWedge will use Profile0, a built-in Profile designed for this purpose.

Details and source code follow.

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Configure DataWedge

Configure DataWedge to output scans via intent:

1. Launch DataWedge via Applications --> DataWedge

2. Select a Profile (Profile0 is used by DataWedge for all apps not explicitly assigned a Profile)

3. Confirm the following Profile settings:

• The Profile is enabled
• Barcode input is enabled
• Intent output is enabled

4. Configure the intent output as follows:

• Intent action: com.dwexample.ACTION (to match value defined in the strings.xml file)
• Intent category: (leave blank)
• Intent delivery: Broadcast intent

The image below shows the correct Profile settings:

See the DataWedge Intent Output guide for more information about these settings.

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Run Application

1. Visit the project page and download, build and launch the sample app.

2. Upon first launch, a screen appears similar to the image below:

3. After scanning a barcode, fields are populated as pictured below:

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Source Code

Main Activity

Below is the sourcecode for the MainActivity.java of the sample app.
For the build.gradle and other resources, visit the app's project page on github.

    
    //
    // WARNING: This app is for demonstration purposes only.
    // It is not intended for use in a production environment
    //
    package com.darryncampbell.datawedgeintentexample1;

    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.content.IntentFilter;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.util.Log;
    import android.widget.ArrayAdapter;
    import android.widget.Spinner;
    import android.widget.TextView;
    import android.widget.Toast;

    import java.util.ArrayList;

    public class MainActivity extends AppCompatActivity {

    // 
    // The section snippet below registers to receive the data broadcast from the
    // DataWedge intent output. In the example, a dynamic broadcast receiver is 
    // registered in the onCreate() call of the target app. Notice that the filtered action 
    // matches the "Intent action" specified in the DataWedge Intent Output configuration.
    // 
    // For a production app, a more efficient way to the register and unregister the receiver 
    // might be to use the onResume() and onPause() calls. 

    // Note: If DataWedge had been configured to start an activity (instead of a broadcast), 
    // the intent could be handled in the app's manifest by calling getIntent() in onCreate(). 
    // If configured as startService, then a service must be created to receive the intent.
    //

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        IntentFilter filter = new IntentFilter();
        filter.addCategory(Intent.CATEGORY_DEFAULT);
        filter.addAction(getResources().getString(R.string.activity_intent_filter_action));
        registerReceiver(myBroadcastReceiver, filter);
    }

    @Override
    protected void onDestroy()
    {
        super.onDestroy();
        unregisterReceiver(myBroadcastReceiver);
    }
    //
    // After registering the broadcast receiver, the next step (below) is to define it.  
    // Here it's done in the MainActivity.java, but also can be handled by a separate class.
    // The logic of extracting the scanned data and displaying it on the screen 
    // is executed in its own method (later in the code). Note the use of the 
    // extra keys defined in the strings.xml file.  
    //  
    private BroadcastReceiver myBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Bundle b = intent.getExtras();

            //
            // The following is useful for debugging to verify
            // the format of received intents from DataWedge:
            //
            // for (String key : b.keySet())
            // {
            //   Log.v(LOG_TAG, key);
            // }
            //

            if (action.equals(getResources().getString(R.string.activity_intent_filter_action))) {
                //
                //  Received a barcode scan
                //

                try {
                    displayScanResult(intent, "via Broadcast");
                } catch (Exception e) {

                //
                // Catch if the UI does not exist when broadcast is received 
                //
                }
            }
        }
    };
    //
    // The section below assumes that a UI exists in which to place the data. A production 
    // application would be driving much of the behavior following a scan.
    //
    private void displayScanResult(Intent initiatingIntent, String howDataReceived)
    {
        String decodedSource = initiatingIntent.getStringExtra(getResources().getString(R.string.datawedge_intent_key_source));
        String decodedData = initiatingIntent.getStringExtra(getResources().getString(R.string.datawedge_intent_key_data));
        String decodedLabelType = initiatingIntent.getStringExtra(getResources().getString(R.string.datawedge_intent_key_label_type));

        final TextView lblScanSource = (TextView) findViewById(R.id.lblScanSource);
        final TextView lblScanData = (TextView) findViewById(R.id.lblScanData);
        final TextView lblScanLabelType = (TextView) findViewById(R.id.lblScanDecoder);
        lblScanSource.setText(decodedSource + " " + howDataReceived);
        lblScanData.setText(decodedData);
        lblScanLabelType.setText(decodedLabelType);
    }
}

Strings.xml

Predefining some of the strings simplifies the process of receiving and extracting the scanned data in the target app. When received, the intent’s action (com.dwexample.ACTION) will contain extras with the scanned data for source, type and data as described in the DataWedge Intent Output guide.

<resources>
    <string name="dw_action">com.dwexample.ACTION</string>
    <string name="datawedge_intent_key_source">com.symbol.datawedge.source</string>
    <string name="datawedge_intent_key_label_type">com.symbol.datawedge.label_type</string>
    <string name="datawedge_intent_key_data">com.symbol.datawedge.data_string</string>
</resources>

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Related Guides

• The original tutorial | by Zebra engineer Darryn Campbell
• DataWedge Intent Output guide | for usage settings and details
• DataWedge APIs | for intent-based functions