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In this video you'll learn how to use
a broadcast block to communicate between sprites
and make a designer sprite walk out on stage.
To start, add a designer sprite
who will receive an award.
Just like on earlier days,
you will create code to move the sprite on to the stage.
Move the sprite to a location
where it will enter the stage.
Drag out a go to block.
Then move the sprite all the way forward on the stage
and add a glide block.
When you test the stack your sprite should glide
on to the stage.
Add a when flag clicked block
and test the code.
Notice that the designer sprite comes on to the stage
at the same time as the models.
Click on the model sprite.
From the events menu drag a broadcast block
to the bottom of the model block stack.
Broadcast blocks allow one sprite to communicate
a message to another sprite or the stage.
In this example the model sprite needs to
tell the designer sprite that it is time to come on stage.
Click on the broadcast drop down, choose new message,
then name the message something like enter stage.
Once the model has run all of its code
it will broadcast the message, enter stage,
to any other sprite that is waiting to receive that message.
Click on the designer sprite.
Right now the code that makes the designer sprite
come on stage is under the when flag clicked event.
You want it to be under the when I receive block
so that the sprite comes on stage after the models.
Drag out the when I receive block
and replace the when flag clicked block
with this new event.
You may need to choose the message, enter stage,
from the broadcast drop down.
Now, when the sprite receives the enter stage message
it will run any code below that block
which will make it glide on to the stage.
Test your code.
The model sprites should enter the stage
then the designer sprite should come
to the front of the stage.
To make the designer appear after the models come on stage
add a when flag clicked and hide block
and snap them together.
Then add a show block immediately after the
when I receive message block.
Reading this code you'll see that when the flag is clicked
the designer sprite hides.
When the designer sprite receives the message,
enter stage, the sprite shows itself,
goes to the entry point of the stage,
and then moves to the middle of the stage
in front of the model.
Try the code.
The designer sprite is now coming to the front of the stage
ready to speak.
Don't worry if you tested a solution and it didn't work!
That happens all the time in computer science!
Keep coding, testing, and trying solutions
until you find one that works!
You can make the sprite say anything you want.
Now it's your turn.
Add a broadcast block to the model code
and name the message.
Add a new sprite as your designer sprite.
Add a when I receive block to the designer
with a show block, go to block, and glide block underneath.
Add a when flag clicked block and a hide block
so the designer isn't shown when the project starts.
Finally, program your designer sprite to talk about
what you've learned and to thank others
who have supported you.
You can also program your sprite to move around the stage.
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