Using the ContentProvider4:23 with Ben Deitch
In this video we'll update MainActivity to use our ContentProvider instead of using the database directly!
We've finished our content provider and now it's time to use it. 0:00 Over in main activity, Let's start by 0:03 clearing out our old database code starting with our dbHelper field. 0:08 Then let's delete this other dbHelper line. 0:14 And inside this if statement, let's just delete dbHelper. 0:17 Leaving us with an unfinished addContact function. 0:22 Then inside updateList, let's get rid of everything except for the first line. 0:27 Awesome. 0:34 Now to finish cleaning up our code, let's head over to DatabaseHelper and 0:36 delete the addContact and getContacts method. 0:40 We can also delete the entire row class. 0:44 All right, now let's get back to main activity and 0:56 start using our content provider. 0:58 Let's start inside our buttons on ClickListener and 1:01 use Alt + Enter to create a new addContact method. 1:04 And let's create it in MainActivity. 1:10 Inside this function, we're going to call the insert method of our content provider. 1:15 Which means we're going to need a content values object. 1:20 So let's start by creating a new instance of content values. 1:23 ConstantValues we'll call it values = new ContentValues. 1:28 Then, on the next line, let's call values.put and then 1:35 we need to pass in the column name for the key and our name for the parameter. 1:40 So let's pass in DatabaseHelper.COLUMN_NAME, 1:45 and then our name parameter. 1:51 Nice. 1:54 Now that we've got our content values object, 1:55 we just need to call the insert method on our content provider. 1:58 And to do that, we'll need to use a ContentResolver. 2:02 So on the next line, 2:06 let's get a ContentResolver by typing getContentResolver. 2:07 And then let's call the insert function which takes in two parameters. 2:11 A URI for where we want to insert the data and 2:15 the data itself as a content values object. 2:18 So let's pass in MyContentProvider.CONTENT_URI for 2:23 the URI and pass in values for the values. 2:28 And nice, and that takes care of inserting the data. 2:32 But just for fun, since we went through the effort to make sure our 2:35 insert function returns a URI, let's toast it. 2:38 Let's store the result of this insert statement into a new URI. 2:42 Then, let's make sure our URI isn't null. 2:51 And if it's not, let's toast back the URI of the newly inserted row. 2:59 Toast.makeText, pass in this for the context, 3:03 and then uri.toString for the message. 3:09 And finally Toast.LENGTH_LONG, so we have enough time to look at it. 3:14 Then let's call .show and groovy. 3:19 All that's left now is the updateList function. 3:23 Inside this function, we're going to use our content provider's query method 3:26 to get a cursor and then we'll loop through that cursor to update the list. 3:30 Let's add a couple lines at the bottom and 3:35 then create a new cursor variable named Cursor. 3:38 And let's set it =getContentResolver.query which takes in the URI of 3:44 the data source and then a bunch of parameters for each part of the SQL query. 3:49 So let's pass in MyContentProvider.CONTENT_URI for the URI. 3:57 And then, since we're just trying to select everything, 4:03 we can pass a null for all four of the parameters we need. 4:06 So null, null, null, and null. 4:09 Cool. 4:16 In the next video, we'll finish up with our content provider and 4:17 finally see it in action. 4:20
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