Thank you for joining me for this video, UDP plugin. For Servoy University, I'm Bob Q. Sick. The UDP plugin allows you to talk to another IP address directly and trigger a method when packets are received. Now, Sir Roy provides a great sample solution called Simple Chat that really displays this perfectly. So what I've done is import the Simple Chat solution. And to do that, I come to the File menu, choose Import, choose Sir Roy, Import solution, and click Next. Then from Browse, navigate to your Application Server, the Solutions folder, and then the Examples, and then you'll find the Simple Chat solution in a list of other solutions. Now, because I've already imported it, I'm going to click Cancel here, and Cancel again. Once it's imported, you'll notice that the solution has two main forms. On the left hand side, there's a list of the users that are logged in, and in the middle pane, there's a form called FRM underscore Chat. In this solution, there's a large HTML area that will display the text, and at the bottom, you can send a text message to one or more other users who are logged in. Now, UDP stands for User Data Grant Protocol. And in this solution, we use port 2828, but you can use whatever port you want to. When you use the UDP plugin, you specify a port and the global method to call when data is received. That way, you can control what happens in your application. Now, this is a Simple Chat application, but you're not limited to just text. You can also send binary data, images, whatever else you want to send to the other user. So to start off, let's take a look at how we start a UDP connection. If we scroll down to the UDP plugins area, and we click on UDP, you can see that you can start a socket, stop a socket, create a new packet, and get a received packet. So in this example file, all of that is done in the globals. So let's have a look at that. Now in this solution, there's a field at the top of the list that allows you to enter a username and click Log In. When you click Log In, it's a simple call to start up a socket. And when you start to socket, there's only two parameters to pass. One is the port number that you want to use, and the second one is to specify what global method gets called when a packet is received. And then when the user clicks the log off button or the solution closes, you need to stop that socket. So we call UDP dot stop socket. When a packet is received from another user, we call this global function packet received. So in line 119, we use a while loop that continues to trigger as long as there's information coming across in that socket. So it's while packet equals plugins dot UDP get received packet is not null. So there's something still coming along the stream. We set a variable called message to the UTF text of that packet. So when we get the received packet, we get back a JS packet object. And this JS packet object allows us to do a number of things. We can get the host, we can get the port. And then we can read either the byte or bytes. We can read integer, shorts or UTF text, which is what we're doing over here in line 120. Once we get the packet in, we try to resolve the IP address of the person that's sent it to us. And then we simply update the HTML area to say it was from so and so user and here's the date and then here's the actual message that got sent. If we come back to our chat form, what we'll see is this HTML area. And then when we send a packet out, there's an on action method that's attached to that FLD underscore message. And that triggers another method. That triggers the send message method. So we'll go ahead and get the local username, we'll set some font colors. We'll try to find all of the users that this message is supposed to go to and try to resolve their IP addresses. Then down here at the bottom is where the magic actually happens. In line 37, we say var packet equals UDP create a new packet. Once we create the new packet, then we get this JS packet object. So in line 37, we save our packet equals UDP create new packet. And then we get a JS packet object. And in this JS packet object, we use the right UTF and we pass in a trimmed string of that message. So the string trim will simply remove any leading or trailing spaces off the message. And then we say plugins. UDP send packet to the IP address with the packet. And that will go ahead and automatically trigger that global method for packet received. And we'll run that on the client. Now because we're communicating from server client to server client, that works out just great. But you can also use the UDP plugin to get information from another device that may be across the internet. And so you can create records in there and create graphs and charts based on that input or whatever you want. Now let's have a look at how this simple chat works in real life. So here I've started up two instances, one in Windows 7 and my virtual machine on the left hand side and on the right hand side, I've started up the same solution in my Mac. I've logged in to the window side as Windows and on the Mac side as Mac. And now we're going to send a message between the two using the UDP plugin. So on my Windows side, I'm going to say hi Mac, I'm Windows. Now I'm going to press the return key and notice on the right hand side on the Mac side that the message appears instantly after I press enter. What's happening here is we're actually connecting with another IP address and we're sending those packets of that text over there. And then on the Mac side, it's taking those packets of text and writing it out. There are all kinds of things that you can do with UDP plugin. It's limited only by your imagination. Thanks for watching.