Power your app with Content Provider

A mobile application must work in every situations.
One of the main problematic to manage while developing is the offline mode.

On Android, one of the way to manage access to the data is the ContentProvider, and it can work offline, but its power doesn't stop there. indeed, it is in the center of the Android system by allowing data sharing across application.

After explaining the basics of the ContentProvider, we will study in more details how it works and how to create one for your application.

Transcript

1. Power your app with
   Content Provider
   Droidcon London 10-24-2013
   

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2. @Mathieu_Calba
   http://bit.ly/11FFK9z
   http://bit.ly/Y7wFiU
   

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3. 1- Basics
   

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4. Definition
   Generic Interface to
   access data
   across multiple Android components
   

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6. Android is built upon
   reusable components
   Activity, Service, Broadcast Receiver,
   Content Provider
   

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7. Android defines how we can
   communicate with them
   Content URIs & Content Resolver for
   Content Provider
   

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8. Content Authority
   A symbolic name to your provider
   (must be unique across every Android applications)
   tips : use your package name & your provider name
   sample : com.mathieucalba.yana.provider
   

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9. An URI that identify data in a provider
   Contains an authority and a path :
   content://content_authority/path...
   samples :
   content://com.mathieucalba.yana.provider/article
   content://com.mathieucalba.yana.provider/article/24
   content://com.mathieucalba.yana.provider/article/24/image
   Content URI
   

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10. Content Types
    A String in MIME that describes the type
    of data returned by a provider for a given
    Content URI
    Contains an type and a subtype : type/subType
    samples :
    vnd.android.cursor.dir/vnd.mathieucalba.yana.article
    vnd.android.cursor.item/vnd.mathieucalba.yana.article
    

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11. ContentResolver
    Handles Content Provider selection
    based upon a Content URI
    CRUD methods (insert, query, update, delete)
    Batch methods (applyBatch, bulkInsert)
    Hides inter-process communication
    

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12. Some public ContentProviders
    Calendar (CalendarContract)
    Contacts (ContactContract)
    Media (MediaStore)
    Dictionary (UserDictionary)
    Any.DO (http://tech.any.do/content-provider-for-any-do/)
    ...
    

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13. 2- Using one
    

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14. query
    ContentResolver resolver = getContentResolver();
    String[] projection = new String[] {UserDictionary.Words._ID,
    UserDictionary.Words.WORD};
    String selectionClause = UserDictionary.Words.WORD + " = ?";
    String[] selectionArgs = new String[] {"Android"};
    String sortOrder = UserDictionary.Words.WORD + " ASC";
    Cursor cursor = resolver.query(UserDictionary.Words.CONTENT_URI,
    projection,
    selectionClause,
    selectionArgs,
    sortOrder);
    

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15. insert
    ContentResolver resolver = getContentResolver();
    ContentValues values = new ContentValues();
    values.put(UserDictionary.Words.WORD, "Droid");
    Uri insertedWordUri = resolver.insert(UserDictionary.Words.CONTENT_URI, values);
    

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16. update
    ContentResolver resolver = getContentResolver();
    ContentValues values = new ContentValues();
    values.put(UserDictionary.Words.WORD, "Droidcon2013");
    String selectionClause = UserDictionary.Words.WORD + " = ?";
    String[] selectionArgs = new String[] {"Droidcon"};
    long nbUpdated = resolver.update(UserDictionary.Words.CONTENT_URI,
    values,
    selectionClause,
    selectionArgs);
    

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17. delete
    ContentResolver resolver = getContentResolver();
    String selectionClause = UserDictionary.Words.WORD + " = ?";
    String[] selectionArgs = new String[] {"Droidcon"};
    long nbDeleted = resolver.delete(UserDictionary.Words.CONTENT_URI,
    selectionClause,
    selectionArgs);
    

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18. These methods block the UI thread
    You must use them on another thread
    (with an AsyncQueryHandler, a CursorLoader,
    a Thread & other classic methods)
    

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19. 3- Creating one
    

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20. Best Practice
    

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21. YANA
    (Yet Another News App)
    Sample application :
    https://github.com/MathieuCalba/android-ui-design-pattern
    

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22. 1- Contract
    public class YANAContract {
    public static String CONTENT_AUTHORITY = "com.mathieucalba.yana.provider";
    protected static Uri BASE_CONTENT_URI = Uri.parse("content://" + CONTENT_AUTHORITY);
    protected static String VENDOR_NAME = "vnd.mathieucalba.yana.";
    protected static final String PATH_ARTICLE = "article";
    public interface Tables {
    String ARTICLE = "article";
    }
    public interface ArticleColumns {
    static final String TITLE = "title"; // Title (TEXT)
    static final String CONTENT = "content"; // Content (TEXT)
    static final String TIMESTAMP = "timestamp"; // Timestamp (INTEGER)
    }
    ...
    

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23. 1- Contract
    public class YANAContract {
    public static String CONTENT_AUTHORITY = "com.mathieucalba.yana.provider";
    protected static Uri BASE_CONTENT_URI = Uri.parse("content://" + CONTENT_AUTHORITY);
    protected static String VENDOR_NAME = "vnd.mathieucalba.yana";
    protected static final String PATH_ARTICLE = "article";
    public interface Tables {
    String ARTICLE = "article";
    }
    public interface ArticleColumns {
    static final String TITLE = "title"; // Title (TEXT)
    static final String CONTENT = "content"; // Content (TEXT)
    static final String TIMESTAMP = "timestamp"; // Timestamp (INTEGER)
    }
    ...
    

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24. 1- Contract
    ...
    public static class ArticleTable implements BaseColumns, ArticleColumns {
    public static final Uri CONTENT_URI = BASE_CONTENT_URI.buildUpon().appendPath(PATH_ARTICLE).build();
    public static final String CONTENT_TYPE = ContentResolver.CURSOR_DIR_BASE_TYPE
    + VENDOR_NAME + PATH_ARTICLE;
    public static final String CONTENT_ITEM_TYPE = ContentResolver.CURSOR_ITEM_BASE_TYPE
    + VENDOR_NAME + PATH_ARTICLE;
    public static final String DEFAULT_SORT = Tables.ARTICLE + "." + ArticleColumns.TIMESTAMP + " DESC";
    /** Build URI for all articles */
    public static Uri buildUri() {
    return CONTENT_URI;
    }
    /** Build URI for one article */
    public static Uri buildUriWithArticleId(int id) {
    return CONTENT_URI.buildUpon().appendPath(String.valueOf(id)).build();
    }
    public static String getId(Uri uri) {
    return uri.getPathSegments().get(1);
    }
    }
    }
    

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25. 1- Contract
    ...
    public static class ArticleTable implements BaseColumns, ArticleColumns {
    public static final Uri CONTENT_URI = BASE_CONTENT_URI.buildUpon().appendPath(PATH_ARTICLE).build();
    public static final String CONTENT_TYPE = ContentResolver.CURSOR_DIR_BASE_TYPE
    + VENDOR_NAME + PATH_ARTICLE;
    public static final String CONTENT_ITEM_TYPE = ContentResolver.CURSOR_ITEM_BASE_TYPE
    + VENDOR_NAME + PATH_ARTICLE;
    public static final String DEFAULT_SORT = Tables.ARTICLE + "." + ArticleColumns.TIMESTAMP + " DESC";
    /** Build URI for all articles */
    public static Uri buildUri() {
    return CONTENT_URI;
    }
    /** Build URI for one article */
    public static Uri buildUriWithArticleId(int id) {
    return CONTENT_URI.buildUpon().appendPath(String.valueOf(id)).build();
    }
    public static String getId(Uri uri) {
    return uri.getPathSegments().get(1);
    }
    }
    }
    

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26. 2- Data
    public class YANADatabase extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "yana_database";
    private static final int DATABASE_VERSION = 1;
    public YANADatabase(Context context, CursorFactory factory, int version) {
    super(context, DATABASE_NAME, factory, version);
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
    createDatabase(db);
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    if (oldVersion == 0) {
    db.execSQL("DROP TABLE article");
    createDatabase(db);
    }
    }
    ...
    

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27. 2- Data
    ...
    protected void createDatabase(SQLiteDatabase db) {
    final String articleTable = "CREATE TABLE " + YANAContract.Tables.ARTICLE //
    + " ('" //
    + BaseColumns._ID + "' INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, '" //
    + YANAContract.ArticleColumns.TITLE + "' TEXT, '" //
    + YANAContract.ArticleColumns.CONTENT + "' TEXT, '" //
    + YANAContract.ArticleColumns.TIMESTAMP + "' TIMESTAMP NOT NULL );";
    db.execSQL(articleTable);
    }
    }
    

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28. 3- Provider
    public class YANAProvider extends ContentProvider {
    protected static UriMatcher sUriMatcher;
    private static final int ARTICLE = 100;
    private static final int ARTICLE_ID = 101;
    protected static UriMatcher buildUriMatcher(final String authority) {
    final UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);
    matcher.addURI(authority, YANAContract.PATH_ARTICLE + "/#", ARTICLE_ID);
    matcher.addURI(authority, YANAContract.PATH_ARTICLE, ARTICLE);
    return matcher;
    }
    protected YANADatabase mDatabase;
    @Override
    public boolean onCreate() {
    mDatabase = new YANADatabase(getContext(), null, YANADatabase.DATABASE_VERSION);
    sUriMatcher = buildUriMatcher(YANAContract.CONTENT_AUTHORITY);
    return true;
    }
    ...
    

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29. 3- Provider
    public class YANAProvider extends ContentProvider {
    protected static UriMatcher sUriMatcher;
    private static final int ARTICLE = 100;
    private static final int ARTICLE_ID = 101;
    protected static UriMatcher buildUriMatcher(final String authority) {
    final UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);
    matcher.addURI(authority, YANAContract.PATH_ARTICLE + "/#", ARTICLE_ID);
    matcher.addURI(authority, YANAContract.PATH_ARTICLE, ARTICLE);
    return matcher;
    }
    protected YANADatabase mDatabase;
    @Override
    public boolean onCreate() {
    mDatabase = new YANADatabase(getContext(), null, YANADatabase.DATABASE_VERSION);
    sUriMatcher = buildUriMatcher(YANAContract.CONTENT_AUTHORITY);
    return true;
    }
    ...
    

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30. 3- Provider
    ...
    @Override
    public String getType(Uri uri) {
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE:
    return YANAContract.ArticleTable.CONTENT_TYPE;
    case ARTICLE_ID:
    return YANAContract.ArticleTable.CONTENT_ITEM_TYPE;
    }
    return null;
    }
    ...
    

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31. 3- Provider
    ...
    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
    String sortOrder) {
    final SQLiteDatabase db = mDatabase.getReadableDatabase();
    if (db == null || !db.isOpen()) {
    return null;
    }
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE: {
    final Cursor c = db.query(YANAContract.Tables.ARTICLE, projection, selection, selectionArgs,
    null, null, sortOrder);
    c.setNotificationUri(getContext().getContentResolver(), uri);
    return c;
    }
    ...
    

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32. 3- Provider
    ...
    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
    String sortOrder) {
    final SQLiteDatabase db = mDatabase.getReadableDatabase();
    if (db == null || !db.isOpen()) {
    return null;
    }
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE: {
    final Cursor c = db.query(YANAContract.Tables.ARTICLE, projection, selection, selectionArgs,
    null, null, sortOrder);
    c.setNotificationUri(getContext().getContentResolver(), uri);
    return c;
    }
    ...
    

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33. 3- Provider
    ...
    case ARTICLE_ID: {
    final StringBuilder select = new StringBuilder();
    if (!TextUtils.isEmpty(selection)) {
    select.append(selection);
    select.append(" AND ");
    }
    select.append(YANAContract.Tables.ARTICLE);
    select.append('.');
    select.append(YANAContract.ArticleTable._ID);
    select.append(" = ");
    select.append(YANAContract.ArticleTable.getId(uri));
    selection = select.toString();
    final Cursor c = db.query(YANAContract.Tables.ARTICLE, projection, selection, selectionArgs,
    null, null, sortOrder);
    c.setNotificationUri(getContext().getContentResolver(), uri);
    return c;
    }
    default:
    if (BuildConfig.DEBUG) {
    Log.w(TAG, "match (" + match + ") is not handled in query");
    }
    return null;
    }
    }
    ...
    

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34. 3- Provider
    ...
    case ARTICLE_ID: {
    final StringBuilder select = new StringBuilder();
    if (!TextUtils.isEmpty(selection)) {
    select.append(selection);
    select.append(" AND ");
    }
    select.append(YANAContract.Tables.ARTICLE);
    select.append('.');
    select.append(YANAContract.ArticleTable._ID);
    select.append(" = ");
    select.append(YANAContract.ArticleTable.getId(uri));
    selection = select.toString();
    final Cursor c = db.query(YANAContract.Tables.ARTICLE, projection, selection, selectionArgs,
    null, null, sortOrder);
    c.setNotificationUri(getContext().getContentResolver(), uri);
    return c;
    }
    default:
    if (BuildConfig.DEBUG) {
    Log.w(TAG, "match (" + match + ") is not handled in query");
    }
    return null;
    }
    }
    ...
    

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35. 3- Provider
    ...
    @Override
    public Uri insert(Uri uri, ContentValues values) {
    final SQLiteDatabase db = mDatabase.getWritableDatabase();
    if (db == null || !db.isOpen()) {
    return null;
    }
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE:
    case ARTICLE_ID: {
    db.insertOrThrow(YANAContract.Tables.ARTICLE, null, values);
    getContext().getContentResolver().notifyChange(uri, null);
    return YANAContract.ArticleTable.buildUriWithArticleId(
    values.getAsInteger(YANAContract.ArticleColumns.ID));
    }
    default:
    if (BuildConfig.DEBUG) {
    Log.w(TAG, "match (" + match + ") is not handled in insert");
    }
    return null;
    }
    }
    ...
    

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36. 3- Provider
    ...
    @Override
    public Uri insert(Uri uri, ContentValues values) {
    final SQLiteDatabase db = mDatabase.getWritableDatabase();
    if (db == null || !db.isOpen()) {
    return null;
    }
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE:
    case ARTICLE_ID: {
    db.insertOrThrow(YANAContract.Tables.ARTICLE, null, values);
    getContext().getContentResolver().notifyChange(uri, null);
    return YANAContract.ArticleTable.buildUriWithArticleId(
    values.getAsInteger(YANAContract.ArticleColumns.ID));
    }
    default:
    if (BuildConfig.DEBUG) {
    Log.w(TAG, "match (" + match + ") is not handled in insert");
    }
    return null;
    }
    }
    ...
    

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37. 3- Provider
    ...
    @Override
    public int update(Uri uri, ContentValues values, String select,
    String[] selectArgs) {
    final SQLiteDatabase db = mDatabase.getWritableDatabase();
    if (db == null || !db.isOpen()) {
    return 0;
    }
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE: {
    ...
    return retVal;
    }
    case ARTICLE_ID: {
    ...
    return retVal;
    }
    default:
    if (BuildConfig.DEBUG) {
    Log.w(TAG, "match (" + match + ") is not handled in update");
    }
    return 0;
    }
    }
    ...
    

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38. 3- Provider
    ...
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE: {
    final int retVal = db.update(YANAContract.Tables.ARTICLE, values, selection, selectionArgs);
    getContext().getContentResolver().notifyChange(uri, null);
    return retVal;
    }
    case ARTICLE_ID: {
    final StringBuilder select = new StringBuilder();
    if (!TextUtils.isEmpty(selection)) {
    select.append(selection);
    select.append(" AND ");
    }
    select.append(YANAContract.Tables.ARTICLE);
    select.append('.');
    select.append(YANAContract.ArticleTable._ID);
    select.append(" = ");
    select.append(YANAContract.ArticleTable.getId(uri));
    selection = select.toString();
    final int retVal = db.update(YANAContract.Tables.ARTICLE, values, selection, selectionArgs);
    getContext().getContentResolver().notifyChange(uri, null);
    return retVal;
    }
    ...
    

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39. 3- Provider
    ...
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE: {
    final int retVal = db.update(YANAContract.Tables.ARTICLE, values, selection, selectionArgs);
    getContext().getContentResolver().notifyChange(uri, null);
    return retVal;
    }
    case ARTICLE_ID: {
    final StringBuilder select = new StringBuilder();
    if (!TextUtils.isEmpty(selection)) {
    select.append(selection);
    select.append(" AND ");
    }
    select.append(YANAContract.Tables.ARTICLE);
    select.append('.');
    select.append(YANAContract.ArticleTable._ID);
    select.append(" = ");
    select.append(YANAContract.ArticleTable.getId(uri));
    selection = select.toString();
    final int retVal = db.update(YANAContract.Tables.ARTICLE, values, selection, selectionArgs);
    getContext().getContentResolver().notifyChange(uri, null);
    return retVal;
    }
    ...
    

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40. 3- Provider
    ...
    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs){
    final SQLiteDatabase db = mDatabase.getWritableDatabase();
    if (db == null || !db.isOpen()) {
    return 0;
    }
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE: {
    ...
    return retVal;
    }
    case ARTICLE_ID: {
    ...
    return retVal;
    }
    default:
    if (BuildConfig.DEBUG) {
    Log.w(TAG, "match (" + match + ") is not handled in delete");
    }
    return 0;
    }
    }
    ...
    

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41. 3- Provider
    ...
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE: {
    final int retVal = db.delete(YANAContract.Tables.ARTICLE, selection, selectionArgs);
    getContext().getContentResolver().notifyChange(uri, null);
    return retVal;
    }
    case ARTICLE_ID: {
    final StringBuilder select = new StringBuilder();
    if (!TextUtils.isEmpty(selection)) {
    select.append(selection);
    select.append(" AND ");
    }
    select.append(YANAContract.Tables.ARTICLE);
    select.append('.');
    select.append(YANAContract.ArticleTable._ID);
    select.append(" = ");
    select.append(YANAContract.ArticleTable.getId(uri));
    selection = select.toString();
    final int retVal = db.delete(YANAContract.Tables.ARTICLE, selection, selectionArgs);
    getContext().getContentResolver().notifyChange(uri, null);
    return retVal;
    }
    ...
    

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42. 3- Provider
    ...
    final int match = sUriMatcher.match(uri);
    switch (match) {
    case ARTICLE: {
    final int retVal = db.delete(YANAContract.Tables.ARTICLE, selection, selectionArgs);
    getContext().getContentResolver().notifyChange(uri, null);
    return retVal;
    }
    case ARTICLE_ID: {
    final StringBuilder select = new StringBuilder();
    if (!TextUtils.isEmpty(selection)) {
    select.append(selection);
    select.append(" AND ");
    }
    select.append(YANAContract.Tables.ARTICLE);
    select.append('.');
    select.append(YANAContract.ArticleTable._ID);
    select.append(" = ");
    select.append(YANAContract.ArticleTable.getId(uri));
    selection = select.toString();
    final int retVal = db.delete(YANAContract.Tables.ARTICLE, selection, selectionArgs);
    getContext().getContentResolver().notifyChange(uri, null);
    return retVal;
    }
    ...
    

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43. 4- Manifest
    package="com.mathieucalba.yana"
    android:installLocation="auto"
    android:versionCode="1"
    android:versionName="1.0" >
    ...
    android:name="com.mathieucalba.yana.UIDesignPatternApplication" >
    ...
    android:name="com.mathieucalba.yana.provider.YANAProvider"
    android:authorities="com.mathieucalba.yana.provider"
    android:exported="false" />
    ...
    
    ...
    
    

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44. 4- CursorLoader
    

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45. CursorLoader
    Manage
    content loading
    from ContentProvider
    on another thread
    

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46. 1- restartLoader
    public class MyFragment extends Fragment implements LoaderCallbacks {
    protected static final int LOADER_ID_BASE_FEED_LIST = 1306170719;
    @Override
    public void onStart() {
    super.onStart();
    if (fragment.getActivity() != null && !fragment.isDetached()) {
    final LoaderManager loaderManager = getActivity().getSupportLoaderManager();
    if (loaderManager != null) {
    loaderManager.restartLoader(LOADER_ID_BASE_FEED_LIST, null, this);
    }
    }
    }
    ...
    

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47. 2- onCreateLoader
    public class MyFragment extends Fragment
    implements LoaderCallbacks {
    ...
    @Override
    public Loader onCreateLoader(int id, Bundle b) {
    if (id == LOADER_ID_BASE_FEED_LIST) {
    Uri uri = YANAContract.ArticleTable.buildUri();
    return new CursorLoader(getActivity(), uri, PROJ_LIST.COLS, null, null,
    YANAContract.ArticleTable.DEFAULT_SORT);
    }
    return null;
    }
    public static class PROJ {
    }
    @Override
    public void onLoadFinished(Loader loader, Cursor cursor) {
    }
    @Override
    public void onLoaderReset(Loader loader) {
    }
    ...
    }
    

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48. 3- Projection
    public class MyFragment extends Fragment
    implements LoaderCallbacks {
    ...
    @Override
    public Loader onCreateLoader(int id, Bundle b) {}
    public static class PROJ {
    public static int _ID = 0;
    public static int TITLE = 1;
    public static int CONTENT = 2;
    public static String[] COLS = new String[] { //
    ArticleColumns._ID, //
    Tables.ARTICLE + "." + ArticleColumns.TITLE, //
    Tables.ARTICLE + "." + ArticleColumns.CONTENT //
    };
    }
    @Override
    public void onLoadFinished(Loader loader, Cursor cursor) {}
    @Override
    public void onLoaderReset(Loader loader) {}
    ...
    }
    

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49. 4- onLoadFinished
    public class MyFragment extends Fragment implements LoaderCallbacks {
    ...
    @Override
    public Loader onCreateLoader(int id, Bundle b) {
    }
    public static class PROJ {
    }
    @Override
    public void onLoadFinished(Loader loader, Cursor cursor) {
    final int id = loader.getId();
    if (id == LOADER_ID_BASE_FEED_LIST) {
    mFeedListAdapter.swapCursor(cursor);
    }
    }
    @Override
    public void onLoaderReset(Loader loader) {
    }
    ...
    }
    

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50. 5- onLoaderReset
    public class MyFragment extends Fragment implements LoaderCallbacks {
    ...
    @Override
    public Loader onCreateLoader(int id, Bundle b) {
    }
    public static class PROJ {
    }
    @Override
    public void onLoadFinished(Loader loader, Cursor cursor) {
    }
    @Override
    public void onLoaderReset(Loader loader) {
    final int id = loader.getId();
    if (id == LOADER_ID_BASE_FEED_LIST) {
    mFeedListAdapter.swapCursor(null);
    }
    }
    ...
    }
    

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51. Be careful with the ids !
    Must be unique
    in one LoaderManager instance !
    

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52. 5- AsyncQueryHandler
    

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53. AsyncQueryHandler
    Manage ContentProvider’s Operation
    (query, insert, update, delete)
    on another thread
    

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54. AsyncQueryHandler
    public class ArticleAsyncTaskLoader extends AsyncQueryHandler {
    protected static final int TOKEN_STAR_ARTICLE = 1304141728;
    public interface StarArticleListener {
    void onStarArticleSuccessfull(String articleId, boolean vote);
    void onStarArticleFailed(String articleId, boolean vote, String error);
    }
    public ArticleAsyncTaskLoader(ContentResolver cr) {
    super(cr);
    }
    public void starArticle(String articleId, boolean vote, StarArticleListener listener) {
    final ContentValues values = new ContentValues();
    values.put(YanaContract.Articles.IS_FAVORITE, vote ? 1 : 0);
    final StarArticleCookie cookie = new StarArticleCookie(listener, articleId, vote);
    final Uri uri = YanaContract.Articles.buildArticleUri(articleId);
    startUpdate(TOKEN_STAR_ARTICLE, cookie, uri, values, null, null);
    }
    ...
    

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55. AsyncQueryHandler
    public class ArticleAsyncTaskLoader extends AsyncQueryHandler {
    protected static final int TOKEN_STAR_ARTICLE = 1304141728;
    public interface StarArticleListener {
    void onStarArticleSuccessfull(String articleId, boolean vote);
    void onStarArticleFailed(String articleId, boolean vote, String error);
    }
    public ArticleAsyncTaskLoader(ContentResolver cr) {
    super(cr);
    }
    public void starArticle(String articleId, boolean vote, StarArticleListener listener) {
    final ContentValues values = new ContentValues();
    values.put(YanaContract.Articles.IS_FAVORITE, vote ? 1 : 0);
    final StarArticleCookie cookie = new StarArticleCookie(listener, articleId, vote);
    final Uri uri = YanaContract.Articles.buildArticleUri(articleId);
    startUpdate(TOKEN_STAR_ARTICLE, cookie, uri, values, null, null);
    }
    ...
    

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56. AsyncQueryHandler
    ...
    protected static class StarArticleCookie {
    final WeakReference mRefListener;
    final String mArticleId;
    final boolean mVote;
    public StarArticleCookie(ArticleAsyncTaskLoader.StarArticleListener listener,
    String articleId, boolean vote) {
    super();
    mRefListener = new WeakReference(listener);
    mArticleId = articleId;
    mVote = vote;
    }
    }
    ...
    

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57. AsyncQueryHandler
    ...
    @Override
    protected void onUpdateComplete(int token, Object cookie, int result) {
    super.onUpdateComplete(token, cookie, result);
    switch (token) {
    case TOKEN_STAR_ARTICLE:
    if (!(cookie instanceof StarArticleCookie)) {
    return;
    }
    final StarArticleCookie cookieStarArticle = (StarArticleCookie) cookie;
    if (result == 0) {
    final WeakReference refListener = cookieStarArticle.mRefListener;
    if (refListener != null) {
    final StarArticleListener listener = refListener.get();
    if (listener != null) {
    listener.onStarArticleFailed(cookieStarArticle.mArticleId, cookieStarArticle.mVote, "");
    }
    }
    return;
    }
    ...
    }
    }
    }
    

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58. AsyncQueryHandler
    ...
    @Override
    protected void onUpdateComplete(int token, Object cookie, int result) {
    super.onUpdateComplete(token, cookie, result);
    switch (token) {
    case TOKEN_STAR_ARTICLE:
    if (!(cookie instanceof StarArticleCookie)) {
    return;
    }
    final StarArticleCookie cookieStarArticle = (StarArticleCookie) cookie;
    if (result == 0) {
    final WeakReference refListener = cookieStarArticle.mRefListener;
    if (refListener != null) {
    final StarArticleListener listener = refListener.get();
    if (listener != null) {
    listener.onStarArticleFailed(cookieStarArticle.mArticleId, cookieStarArticle.mVote, "");
    }
    }
    return;
    }
    ...
    }
    }
    }
    

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59. AsyncQueryHandler
    ...
    @Override
    protected void onUpdateComplete(int token, Object cookie, int result) {
    super.onUpdateComplete(token, cookie, result);
    switch (token) {
    case TOKEN_STAR_ARTICLE:
    ...
    if (result == 0) {
    ...
    return;
    }
    final WeakReference refListener = cookieStarArticle.mRefListener;
    if (refListener != null) {
    final StarArticleListener listener = refListener.get();
    if (listener != null) {
    listener.onStarArticleSuccessfull(cookieStarArticle.mArticleId, cookieStarArticle.mVote);
    }
    }
    break;
    default:
    break;
    }
    }
    }
    

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60. AsyncQueryHandler
    public class MyFragment extends Fragment implements ArticleAsyncTaskLoader.StarArticleListener{
    public starArticle(int articleId, boolean addFavorite) {
    final ContentResolver cr = getActivity().getContentResolver();
    new ArticleAsyncTaskLoader(cr).starArticle(articleId, addFavorite, this);
    }
    @Override
    public void onStarArticleSuccessfull(String articleId, boolean vote) {
    // inform user
    }
    @Override
    public void onStarArticleFailed(String articleId, boolean vote, String error) {
    // inform user
    }
    }
    

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61. 6- More to explore
    

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62. Batching requests
    ContentProviderOperation is an helper class to create Query, Insert,
    Update & Delete requests to a ContentProvider :
    ContentProviderOperation.newAssertQuery(Uri uri);
    ContentProviderOperation.newInsert(Uri uri);
    ContentProviderOperation.newUpdate(Uri uri);
    ContentProviderOperation.newDelete(Uri uri);
    Used with ContentResolver’s apply batch method :
    ContentProviderResult[] applyBatch(String authority, ArrayList operations)
    throws RemoteException, OperationApplicationException;
    

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63. Attach Database (Multiple database used like only one : SQL
    keyword : ATTACH)
    ProviderTestCase2 (Unit test your provider)
    Using data URI on your activities to open activities based on Content
    URIs
    

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64. Thanks
    

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65. Questions ?
    @Mathieu_Calba
    

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