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Configuring the AlertDialog
5:58We can configure an Alert Dialog by chaining a few key methods together and then building it.
We're off to a great start
with our alert dialog, so
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that we can notify users
if an error occurs.
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We need to continue on with it and
configure the dialog and then return it.
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The title that appears at
the top of the dialog is set,
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using the builder.setTitle method.
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So under here, builder Set title.
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Just do Oops!
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Sorry.
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We can next add a detailed message.
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We could add another line calling
the builder.setMessage method.
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Or we can chain methods together.
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We've seen method chaining
before with toast messages.
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I find it allows for
code to be easier to read and understand.
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So let's do that here.
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Before the semi colon then, hit Enter, And
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type, .setMessage.
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And our message will be,
there was an error.
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Please try again.
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Finally, we need to add buttons
to the bottom of the dialogue.
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We can add one, two, or three of them.
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The alert dialogue has three different
buttons we can set, positive,
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negative, and neutral.
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For each button, we set the text and
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the onClick listener which runs
code when the button is tapped on.
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For this dialogue, we just want
one positive button labeled OK.
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So let's chain that to our builder.
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SetPositiveButton.
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And we'll pass in null for
OnClickListener.
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So we can use null like this if we
don't want to do anything specific when
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the button is tapped.
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A null, OnClickListener, will just close
the dialog, which is all we need here.
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However, we could add an OnClickListener
just like a regular button.
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With our dialogue defined using the
builder, we need to create and return it.
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We create an actual alert dialogue object
by using our builder's create method.
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And we can return it directly.
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Return builder.create.
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While we're in our
AlertDialogFragment file,
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there's one more thing
we should do in here.
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To follow Android best practices,
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we should use string resources
wherever possible in our apps.
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We've seen them a little
in previous courses and
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it's great to use them wherever we can.
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Fortunately, Android Studio makes
this easy with a convenient shortcut.
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Place your cursor in the title string and
hit Alt+Enter for the quick fix.
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To extract string resource,
and we'll do error_title.
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We can do the same for message.
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Alt+Enter, extract string resource,
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[INAUDIBLE] error_message.
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In here, same thing, and
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we'll call it error_button_ok_text.
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So we're getting an error here,
let's just try rebuilding the project.
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And the errors go away, great.
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Now we need to use this new
object in our activity.
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Let's head back to our new
alertUserAboutError method and
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put it to work.
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So back here in MainActivity,
and alertUserAboutError.
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Let's create a new AlertDialogFragment.
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We'll call it dialog and
say new AlertDialogFragment.
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Now we need to show it in our activity.
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We can do that with dialog.show.
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This takes a couple of parameters,
the first being a fragment manager.
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Fortunately, the activity has a method for
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this called getFragmentManager,
which we can pass in.
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The second parameter is
a tag that is just a string.
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We can put in pretty
much whatever we want.
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So, let's just put in
error dialog over there,
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dialog.show.
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Get fragment manager.
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And our string, error dialog.
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And our semicolon.
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We're all set.
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In order to test our dialogue though,
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we need to force some
kind of error in our app.
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One easy way to cause
our web request to fail,
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is to alter the parameters
we're passing into our URL.
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We just need to keep in
mind what we changed, and
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fix it right away after the test.
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Let's go up to latitude.
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Here let's comment out this value.
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And let's just set it to a number
we know doesn't work like 9999.
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Great, now we can run it and test it out.
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Nice, our dialogue appears,
and we tap the OK button.
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We go back to the activity.
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Now with that test done let's not forget
to change our latitude value back.
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Cool, we're off to a great
start with handling errors when
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something goes wrong
with a network request.
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What happens if the network
isn't available at all though?
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We'll see how to handle that next.
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