Making TV Apps Searchable

Making TV Apps Searchable

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This lesson teaches you to

1. Identify Columns
2. Provide Search Suggestion Data
3. Handle Search Suggestions
4. Handle Search Terms
5. Deep Link to Your App in the Details Screen

You should also read

• Search
• Adding Search Functionality

Try it out

• Android Leanback sample app

Android TV uses the Android search interface to retrieve content data from installed apps and deliver search results to the user. Your app's content data can be included with these results, to give the user instant access to the content in your app.

Your app must provide Android TV with the data fields from which it generates suggested search results as the user enters characters in the search dialog. To do that, your app must implement a Content Provider that serves up the suggestions along with a searchable.xml configuration file that describes the content provider and other vital information for Android TV. You also need an activity that handles the intent that fires when the user selects a suggested search result. All of this is described in more detail in Adding Custom Suggestions. Here are described the main points for Android TV apps.

This lesson builds on your knowledge of using search in Android to show you how to make your app searchable in Android TV. Be sure you are familiar with the concepts explained in the Search API guide before following this lesson. See also the training Adding Search Functionality.

This discussion describes some code from the Android Leanback sample app, available on GitHub.

Identify Columns

The SearchManager describes the data fields it expects by representing them as columns of an SQLite database. Regardless of your data's format, you must map your data fields to these columns, usually in the class that accessess your content data. For information about building a class that maps your existing data to the required fields, see Building a suggestion table.

The SearchManager class includes several columns for Android TV. Some of the more important columns are described below.

Value	Description
SUGGEST_COLUMN_TEXT_1	The name of your content (required)
SUGGEST_COLUMN_TEXT_2	A text description of your content
SUGGEST_COLUMN_RESULT_CARD_IMAGE	An image/poster/cover for your content
SUGGEST_COLUMN_CONTENT_TYPE	The MIME type of your media (required)
SUGGEST_COLUMN_VIDEO_WIDTH	The resolution width of your media
SUGGEST_COLUMN_VIDEO_HEIGHT	The resolution height of your media
SUGGEST_COLUMN_PRODUCTION_YEAR	The production year of your content (required)
SUGGEST_COLUMN_DURATION	The duration in milliseconds of your media (required)

The search framework requires the following columns:

• SUGGEST_COLUMN_TEXT_1
• SUGGEST_COLUMN_CONTENT_TYPE
• SUGGEST_COLUMN_PRODUCTION_YEAR
• SUGGEST_COLUMN_DURATION

When the values of these columns for your content match the values for the same content from other providers found by Google servers, the system provides a deep link to your app in the details view for the content, along with links to the apps of other providers. This is discussed more in Display Content in the Details Screen, below.

Your application's database class might define the columns as follows:

public class VideoDatabase {
  //The columns we'll include in the video database table
  public static final String KEY_NAME = SearchManager.SUGGEST_COLUMN_TEXT_1;
  public static final String KEY_DESCRIPTION = SearchManager.SUGGEST_COLUMN_TEXT_2;
  public static final String KEY_ICON = SearchManager.SUGGEST_COLUMN_RESULT_CARD_IMAGE;
  public static final String KEY_DATA_TYPE = SearchManager.SUGGEST_COLUMN_CONTENT_TYPE;
  public static final String KEY_IS_LIVE = SearchManager.SUGGEST_COLUMN_IS_LIVE;
  public static final String KEY_VIDEO_WIDTH = SearchManager.SUGGEST_COLUMN_VIDEO_WIDTH;
  public static final String KEY_VIDEO_HEIGHT = SearchManager.SUGGEST_COLUMN_VIDEO_HEIGHT;
  public static final String KEY_AUDIO_CHANNEL_CONFIG =
          SearchManager.SUGGEST_COLUMN_AUDIO_CHANNEL_CONFIG;
  public static final String KEY_PURCHASE_PRICE = SearchManager.SUGGEST_COLUMN_PURCHASE_PRICE;
  public static final String KEY_RENTAL_PRICE = SearchManager.SUGGEST_COLUMN_RENTAL_PRICE;
  public static final String KEY_RATING_STYLE = SearchManager.SUGGEST_COLUMN_RATING_STYLE;
  public static final String KEY_RATING_SCORE = SearchManager.SUGGEST_COLUMN_RATING_SCORE;
  public static final String KEY_PRODUCTION_YEAR = SearchManager.SUGGEST_COLUMN_PRODUCTION_YEAR;
  public static final String KEY_COLUMN_DURATION = SearchManager.SUGGEST_COLUMN_DURATION;
  public static final String KEY_ACTION = SearchManager.SUGGEST_COLUMN_INTENT_ACTION;
...

When you build the map from the SearchManager columns to your data fields, you must also specify the _IDto give each row a unique ID.

...
  private static HashMap buildColumnMap() {
    HashMap map = new HashMap();
    map.put(KEY_NAME, KEY_NAME);
    map.put(KEY_DESCRIPTION, KEY_DESCRIPTION);
    map.put(KEY_ICON, KEY_ICON);
    map.put(KEY_DATA_TYPE, KEY_DATA_TYPE);
    map.put(KEY_IS_LIVE, KEY_IS_LIVE);
    map.put(KEY_VIDEO_WIDTH, KEY_VIDEO_WIDTH);
    map.put(KEY_VIDEO_HEIGHT, KEY_VIDEO_HEIGHT);
    map.put(KEY_AUDIO_CHANNEL_CONFIG, KEY_AUDIO_CHANNEL_CONFIG);
    map.put(KEY_PURCHASE_PRICE, KEY_PURCHASE_PRICE);
    map.put(KEY_RENTAL_PRICE, KEY_RENTAL_PRICE);
    map.put(KEY_RATING_STYLE, KEY_RATING_STYLE);
    map.put(KEY_RATING_SCORE, KEY_RATING_SCORE);
    map.put(KEY_PRODUCTION_YEAR, KEY_PRODUCTION_YEAR);
    map.put(KEY_COLUMN_DURATION, KEY_COLUMN_DURATION);
    map.put(KEY_ACTION, KEY_ACTION);
    map.put(BaseColumns._ID, "rowid AS " +
            BaseColumns._ID);
    map.put(SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID, "rowid AS " +
            SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID);
    map.put(SearchManager.SUGGEST_COLUMN_SHORTCUT_ID, "rowid AS " +
            SearchManager.SUGGEST_COLUMN_SHORTCUT_ID);
    return map;
  }
...

In the example above, notice the mapping to the SUGGEST_COLUMN_INTENT_DATA_ID field. This is the portion of the URI that points to the content unique to the data in this row — that is, the last part of the URI describing where the content is stored. The first part of the URI, when it is common to all of the rows in the table, is set in the searchable.xml file as the android:searchSuggestIntentData attribute, as described in Handle Search Suggestions, below.

If the first part of the URI is different for each row in the table, you map that value with the SUGGEST_COLUMN_INTENT_DATA field. When the user selects this content, the intent that fires provides the intent data from the combination of the SUGGEST_COLUMN_INTENT_DATA_ID and either the android:searchSuggestIntentData attribute or the SUGGEST_COLUMN_INTENT_DATA field value.

Provide Search Suggestion Data

Implement a Content Provider to return search term suggestions to the Android TV search dialog. The system queries your content provider for suggestions by calling the query() method each time a letter is typed. In your implementation of query(), your content provider searches your suggestion data and returns a Cursor that points to the rows you have designated for suggestions.

@Override
  public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
                      String sortOrder) {
    // Use the UriMatcher to see what kind of query we have and format the db query accordingly
    switch (URI_MATCHER.match(uri)) {
      case SEARCH_SUGGEST:
          Log.d(TAG, "search suggest: " + selectionArgs[0] + " URI: " + uri);
          if (selectionArgs == null) {
              throw new IllegalArgumentException(
                      "selectionArgs must be provided for the Uri: " + uri);
          }
          return getSuggestions(selectionArgs[0]);
      default:
          throw new IllegalArgumentException("Unknown Uri: " + uri);
    }
  }

  private Cursor getSuggestions(String query) {
    query = query.toLowerCase();
    String[] columns = new String[]{
      BaseColumns._ID,
      VideoDatabase.KEY_NAME,
      VideoDatabase.KEY_DESCRIPTION,
      VideoDatabase.KEY_ICON,
      VideoDatabase.KEY_DATA_TYPE,
      VideoDatabase.KEY_IS_LIVE,
      VideoDatabase.KEY_VIDEO_WIDTH,
      VideoDatabase.KEY_VIDEO_HEIGHT,
      VideoDatabase.KEY_AUDIO_CHANNEL_CONFIG,
      VideoDatabase.KEY_PURCHASE_PRICE,
      VideoDatabase.KEY_RENTAL_PRICE,
      VideoDatabase.KEY_RATING_STYLE,
      VideoDatabase.KEY_RATING_SCORE,
      VideoDatabase.KEY_PRODUCTION_YEAR,
      VideoDatabase.KEY_COLUMN_DURATION,
      VideoDatabase.KEY_ACTION,
      SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID
    };
    return mVideoDatabase.getWordMatch(query, columns);
  }
...

In your manifest file, the content provider receives special treatment. Rather than getting tagged as an activity, it is described as a <provider>. The provider includes the android:searchSuggestAuthority attribute to tell the system the namespace of your content provider. Also, you must set its android:exported attribute to"true" so that the Android global search can use the results returned from it.

<provider android:name="com.example.android.tvleanback.VideoContentProvider"
    android:authorities="com.example.android.tvleanback"
    android:exported="true" />

Handle Search Suggestions

Your app must include a res/xml/searchable.xml file to configure the search suggestions settings. It inlcudes the android:searchSuggestAuthority attribute to tell the system the namespace of your content provider. This must match the string value you specify in the android:authorities attribute of the <provider> element in your AndroidManifest.xml file.

The  searchable.xml file must also include the  android:searchSuggestIntentAction with the value  "android.intent.action.VIEW" to define the intent action for providing a custom suggestion. This is different from the intent action for providing a search term, explained below. See also,  Declaring the intent actionfor other ways to declare the intent action for suggestions.

Along with the intent action, your app must provide the intent data, which you specify with theandroid:searchSuggestIntentData attribute. This is the first part of the URI that points to the content. It describes the portion of the URI common to all rows in the mapping table for that content. The portion of the URI that is unique to each row is established with the SUGGEST_COLUMN_INTENT_DATA_ID field, as described above in Identify Columns. See also, Declaring the intent data for other ways to declare the intent data for suggestions.

Also, note the android:searchSuggestSelection=" ?" attribute which specifies the value passed as the selection parameter of the query() method where the question mark (?) value is replaced with the query text.

Finally, you must also include the android:includeInGlobalSearch attribute with the value "true". Here is an example searchable.xml file:

<searchable xmlns:android="http://schemas.android.com/apk/res/android"
    android:label="@string/search_label"
        android:hint="@string/search_hint"
        android:searchSettingsDescription="@string/settings_description"
        android:searchSuggestAuthority="com.example.android.tvleanback"
        android:searchSuggestIntentAction="android.intent.action.VIEW"
        android:searchSuggestIntentData="content://com.example.android.tvleanback/video_database_leanback"
        android:searchSuggestSelection=" ?"
        android:searchSuggestThreshold="1"
        android:includeInGlobalSearch="true"
    >
</searchable>

Handle Search Terms

As soon as the search dialog has a word which matches the value in one of your app's columns (described in Identifying Columns, above), the system fires the ACTION_SEARCH intent. The activity in your app which handles that intent searches the repository for columns with the given word in their values, and returns a list of content items with those columns. In your AndroidManifest.xml file, you designate the activity which handles the ACTION_SEARCH intent like this:

...
  <activity
      android:name="com.example.android.tvleanback.DetailsActivity"
      android:exported="true">

      <!-- Receives the search request. -->
      <intent-filter>
          <action android:name="android.intent.action.SEARCH" />
          <!-- No category needed, because the Intent will specify this class component -->
      </intent-filter>

      <!-- Points to searchable meta data. -->
      <meta-data android:name="android.app.searchable"
          android:resource="@xml/searchable" />
  </activity>
...
  <!-- Provides search suggestions for keywords against video meta data. -->
  <provider android:name="com.example.android.tvleanback.VideoContentProvider"
      android:authorities="com.example.android.tvleanback"
      android:exported="true" />
...

The activity must also describe the searchable configuration with a reference to the searchable.xml file. To use the global search dialog, the manifest must describe which activity should receive search queries. The manifest must also describe the <provider> element, exactly as it is described in the searchable.xml file.

Deep Link to Your App in the Details Screen

If you have set up the search configuration as described in Handle Search Suggestions and mapped the SUGGEST_COLUMN_TEXT_1, SUGGEST_COLUMN_CONTENT_TYPE, and SUGGEST_COLUMN_PRODUCTION_YEARfields as described in Identify Columns, a deep link to a watch action for your content appears in the details screen that launches when the user selects a search result, as shown in figure 1.

Figure 1. The details screen displays a deep link for the Videos by Google (Leanback) sample app. Sintel: © copyright Blender Foundation, www.sintel.org.

When the user selects the link for your app, identified by the "Available On" button in the details screen, the system launches the activity which handles the ACTION_VIEW (set as android:searchSuggestIntentAction with the value "android.intent.action.VIEW" in the searchable.xml file).

You can also set up a custom intent to launch your activity, and this is demonstrated in the Android Leanback sample app. Note that the sample app launches its own LeanbackDetailsFragment to show the details for the selected media, but you should launch the activity that plays the media immediately to save the user another click or two.