Dicoding Developer Coaching merupakan webinar, yang membahas tuntas kendala maupun pertanyaan yang sering ditanyakan di Academy Dicoding. Tema kali ini adalah "Apa itu Content Provider?" Di sini Anda akan belajar mengenai komponen Content Provider. Pada dasarnya Content Provider bukanlah sebuah mekanisme penyimpanan di Android. Ia merupakan sebuah antarmuka untuk menjadikan aplikasi sebagai penyedia data bagi aplikasi lain di dalam sebuah peranti.

1. Ahmad Arif Faizin
Google Associate Android Developer, Curriculum Developer Dicoding

2. Penyedia data untuk aplikasi lain

4. // Sets the columns to retrieve for the user profile
val projection = arrayOf(
ContactsContract.Profile._ID,
ContactsContract.Profile.DISPLAY_NAME_PRIMARY,
ContactsContract.Profile.PHOTO_THUMBNAIL_URI,
)
// Retrieves the profile from the Contacts Provider
val profileCursor = contentResolver.query(
ContactsContract.Profile.CONTENT_URI,
projection,
null,null,null //selection, selectionArgs, sortOrder
)

5. ● ContentResolver : used to access data in a content provider. The
ContentResolver methods provide the basic "CRUD" (create, read, update, and
delete) functions of persistent storage.
● Content URIs : used to identify data in a provider. Content URIs include the
symbolic name of the entire provider (its authority) and a name that points to a
table (a path).
● Provider : a class that inherits to ContentProvider to implement CRUD operation
to database.

6. 1. Buat Provider Class yang extends ke ContentProvider
2. Daftarkan Provider Class di Manifest
3. Tentukan Content URI
4. Tambah URI ke Contract Class
5. Buat URI Matcher
6. Lengkapi fungsi CRUD yang dibutuhkan
7. Coba untuk akses menggunakan ContentResolver

7. class NoteProvider : ContentProvider() {
private lateinit var noteHelper: NoteHelper
override fun onCreate(): Boolean {
// database initialization
noteHelper = NoteHelper.getInstance(context as Context)
noteHelper.open()
return true
}
}

8. <manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.dicoding.picodiploma.mynotesapp">
<permission android:name="com.dicoding.picodiploma.mynotesapp.READ_DATABASE"
android:protectionLevel="normal" />
<permission android:name="com.dicoding.picodiploma.mynotesapp.WRITE_DATABASE"
android:protectionLevel="normal" />
<application...>
...
<provider
android:authorities="com.dicoding.picodiploma.mynotesapp"
android:name=".provider.NoteProvider"
android:exported="true"
android:readPermission="com.dicoding.picodiploma.mynotesapp.READ_DATABASE"
android:writePermission="com.dicoding.picodiploma.mynotesapp.WRITE_DATABASE"/>
</application>
</manifest>

9. ● Format:
<scheme>://<authorities>/<path>
<scheme>://<authorities>/<path>/# (untuk number)
<scheme>://<authorities>/<path>/* (untuk string)
● Example:
○ Get All Note:
content://com.dicoding.picodiploma.mynotesapp/note
○ Note with id:
content://com.dicoding.picodiploma.mynotesapp/note/#

10. object DatabaseContract {
const val AUTHORITY = "com.dicoding.picodiploma.mynotesapp"
const val SCHEME = "content"
class NoteColumns : BaseColumns {
companion object {
…
//result = content://com.dicoding.picodiploma.mynotesapp/note
val CONTENT_URI: Uri = Uri.Builder()
.scheme(SCHEME)
.authority(AUTHORITY)
.appendPath(TABLE_NAME)
.build()
}
}
}

11. class NoteProvider : ContentProvider() {
companion object {
private const val NOTE = 1
private const val NOTE_ID = 2
private val sUriMatcher = UriMatcher(UriMatcher.NO_MATCH)
init {
// content://com.dicoding.picodiploma.mynotesapp/note
sUriMatcher.addURI(AUTHORITY, TABLE_NAME, NOTE)
// content://com.dicoding.picodiploma.mynotesapp/note/id
sUriMatcher.addURI(AUTHORITY, "$TABLE_NAME/#", NOTE_ID)
}
}
...
}

12. class NoteProvider : ContentProvider() {
override fun query(uri: Uri, strings: Array<String>?, s: String?,
strings1: Array<String>?, s1: String?): Cursor? {
return when (sUriMatcher.match(uri)) {
// content://com.dicoding.picodiploma.mynotesapp/note
NOTE -> noteHelper.queryAll()
// content://com.dicoding.picodiploma.mynotesapp/note/1
NOTE_ID -> noteHelper.queryById(uri.lastPathSegment.toString())
else -> null
}
}
override fun insert(...): Uri? {...}
override fun update(...): Int {...}
override fun delete(...): Int {...}
}

13. val uriWithId = Uri.parse(CONTENT_URI.toString() + "/" + note?.id)
val cursor = contentResolver.query(uriWithId, null, null, null, null)
val cursor = contentResolver.query(CONTENT_URI,null, null, null, null)
● Get All Data
● Get Data by id

14. contentResolver.update(uriWithId, values, null, null)
contentResolver.insert(CONTENT_URI, values)
● Insert Data
● Update Data
contentResolver.delete(uriWithId, null, null)
● Delete Data

18. <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.dicoding.picodiploma.consumerapp">
<uses-permission android:name="com.dicoding.picodiploma.mynotesapp.READ_DATABASE"/>
<uses-permission android:name="com.dicoding.picodiploma.mynotesapp.WRITE_DATABASE"/>
...
<queries>
<package android:name="com.dicoding.picodiploma.mynotesapp" />
</queries>
</manifest>

19. Contact:
@arif_faizin
Follow us: @dicoding