Framework on which to build

1
Framework on which to build

• Quick review of LoadVars and event handling
• The example user interface
• Some example Flash code
• Discussion of the framework
• Actions for you to carry out
• Further reading

2
LoadVars example ActionScript

• Creates new LoadVars objects and initialises one
  to hold a couple of variables - This is what we
  will send to the server
• var lvOutputLoadVars new LoadVars()
• var lvInputLoadVars new LoadVars()
• lvOutput.myStatus "Info text here"
• lvOutput.myData "123456"
• Odd looking way of creating variables!
• Variables are treated as custom properties of
  objects

3
LoadVars example ActionScript

• When we receive the response from the server,
  just print it to the debugging console
• lvInput.onLoad function(bOkayBoolean)
• if(bOkay true)
• trace("Reply1 was " lvInput.myVar1)
• trace("Reply2 was " lvInput.myVar2)
• trace("Reply3 was " lvInput.someOtherInfo)
• else trace("No reply from server script.")
• Sends our message to a script and get ready for a
  response
• lvOutput.sendAndLoad("myScript.php", lvInput,
  "POST")

4
LoadVars example PHP

• Expects form-like data. We will reply through
  variables
• lt?php// reads data POSTed from a form
• myInput1 _POST('myStatus')
• myInput2 _POST('myData')

5
LoadVars example PHP

• Sends some data back to the client
• // ends up doing simple text output
• echo "myVar1myInput1"
• echo "myVar2myInput2"
• echo "someOtherInfo12345678"
• This automatically creates the attributes
  lvInput.myVar1, lvInput.myVar2 and
  lvInput.someOtherInfo when Flash receives the
  data
• Very easy to use!

6
The example interface
7
The example user interface

• Each button calls the same script but sends a
  different command
• Each button triggers this sequence
• Set variables in lvOutput
• Set lvInputs onLoad handler to point to a
  function
• Call the PHP script and asks for data to go to
  lvInput
• Then, when the PHP has run (some time later)
• Data comes back from the server and gets put into
  lvInput
• Our onLoad function runs
• It reads the variables out of lvInput and puts
  them in a label

8
Some Flash ActionScript

• info_btn.onPress function ()
• fnTalkToServer("getInfo", "1", "",
  fnBasicCallBack)
• feedback_txt.text "Get Info(1) ..."
• function fnTalkToServer(sStatusString,
  sData1String, sData2String, fnCallBackFunction)
  Void
• lvOutput.ntStatus sStatus
• lvOutput.ntData1 sData1
• lvOutput.ntData2 sData2
• lvInput.onLoad fnCallBack
• lvOutput.sendAndLoad("newTechExample.php",
  lvInput, "POST")

9
Some Flash ActionScript

• function fnBasicCallBack(bOkayBoolean)Void
• if (bOkay true)
• / trace("Got server reply")
• trace(lvInput.ntStatus)
• trace(lvInput.ntData1)
• trace(lvInput.ntData2)
• /
• feedback_txt.text lvInput.ntData1
• else
• feedback_txt.text "Could not load data from
  server"

10
A framework for re-use

• The example gives information on one item only
• It does not connect to a database
• It does not allow for stored user feedback
• But it does show how you can interact with a
  server from Flash
• It demonstrates how to pass simple commands and
  get simple replies
• It implements one function the image loader,
  this could be any data (e.g. MP3 sound for the
  MP3 player example)

11
Actions for you

• Get a copy of the framework
• Put the copy into your server area
• Get it working
• Only when it is working
• Make a new copy
• Modify it to provide different information
• Make the system show a different image
• Then think about what you need for your choice of
  assignment topic

12
Further Reading

• Client/Server Frequently Asked Questionshttp//w
  ww.faqs.org/faqs/client-server-faq/index.html
• LoadVars with PHP http//www.sephiroth.it/tutoria
  ls/flashPHP/loadVars/
• ActionScripts.org, LoadVariables and LoadVars
  Objects http//www.actionscripts.org/tutorials/b
  eginner/loadVariables_and_loadVars/index.shtml