Creating Databases for Web Applications Reprise: Systems design (diagrams) Flash to php Homework: Prepare for quiz.

Creating Databases for Web Applications

Reprise: Systems design (diagrams)

Flash to php

Homework: Prepare for quiz

Systems design

• Focus on information– what is the information and how do [things]

relate– Entity relationship diagrams is tool– Information may exist already in the

organization

• Focus on function of application(s)– who does what– … using what information

System design

• slow down rush to implement

• [start] documentation

• Design and documentation may change as system is being built, deployed, refined….

• Still, goal is to decrease bugs

ER diagram

• Database holds– Tables. Table represents one type of entity

Row in table holds information on one example of the entity– Row in table made up of

• Attributes (aka fields)

• Lines connecting tables indicate occurrence of attribute in one table that points to a row in another table (or that table)– What is the pointer? The id of the row. This is called a foreign

key.

• Seems simple but recall how definition of library changed (evolved) during discussion

Store

• Vendors (suppliers)– v_id, name, address

• Shipments from vendors– s_id, vendor=v_id, expected_date, status (orders,

received, partial), billed_amount

• Item_in_shipment– i_ship_id, s_id, p_id

• Products– p_id, name/description, vendor=v_id, size, type,

quantity_in_stock, cost, base_price

Design to build

• Use system design to plan• Decide on technologies

– software & hardware• For example, what programming languages? what DBMS?

who does / who can do each process? should application be customized for PDA (e.g., IPOD)

• Plan / invoke usability standards. Plan testing / involvement of users

• Allocate and schedule work– refine / update documentation

• Deploy / deliver / distribute

Software decision

• What already exists?– inside organization– generally available

• something such as Google Maps API?• Open source• Make / buy

• What is level of expertise in organization?

Example: What are pros/cons

• JavaScript

• Processing

• ActionScript

ActionScript

• Continue with implementation of video clip archive

• NOTE: ActionScript invoking and getting something back from php scripts

• Compare to:– html action=php script – THEN php creates a new html file

Aside

• html is interpreted by the browser on the client computer

• php is interpreted by the php engine installed on the server computer

• SQL is interpreted by the MySQL program on the server computer.

ActionScript basicsCode, that is, ActionScript is• in the .fla file,

– created in the Flash development environment using the Actions panel

– associated with frame

• in separate .as files– created in the Flash development environment– each file formatted as a package

• named class in Document package• named class in named package

ActionScript basics review• Data is in internal variables or dynamic or input

text fields on the Stage– Text field needs a name. Get contents by .text

attribute• fromaddress.text

• Set up response to event using addEventListener(name of event, function)– sendbtn.addEventListener(MouseEvent.CLICK,

sendemail);– loader.addEventListener(Event.COMPLETE,

getfromdb);

ActionScript to/from php

• URLRequest object: holds the php file name• URLVariables object: holds the data sent to php• URLLoader object: holds the data from php• NOTE: this is not instant! It is asynchronous

process. Need to wait for the Event.COMPLETE event

• Look at specific code!

Bo Email example: from sendemail function: 1 direction, don't need to use URLLoader

var request:URLRequest = new URLRequest("sendemail.php");var variables:URLVariables = new URLVariables();var gameURL:String =

"http://newmedia.purchase.edu/~Jeanine/as30/chasebothedogemailb.html"

//multiple inputs to the phpvariables.body="I caught Bo on "+caught+". Visit "+gameURL;variables.to=toaddress.text;variables.subject="news";variables.from = fromaddress.text;

request.data = variables;request.method=URLRequestMethod.POST;sendToURL(request);

}

Bo email example: sendemail.php

<?php $to = $_POST['to'];

$subject = $_POST['subject']; $body = $_POST['body'];

$headers = "From: " . $_POST['from']; if (mail($to, $subject, $body,$headers)) { echo("Your message was sent"); } else { echo("There was a problem."); } /* the error messages will not appear if called from Flash

application, but will appear if called from html */?>

Video example

• choosevideoplay.fla uses an external Class definition

• Video3.as– Invokes php functions to get information to

populate each of two ComboBox components– Note: the data returned is the name of the

video file NOT the video file itself.

Video example: cbHandler: a group of clips has been selected, the group name is to be sent to php

private function cbHandler(event:Event):void { aTa.text = "Group: " + event.target.selectedItem.data; var variables:URLVariables = new URLVariables (); variables.group = event.target.selectedItem.data; var request:URLRequest = new URLRequest(); request.data = variables; request.url = "getgroupclips.php"; var loader:URLLoader = new URLLoader(); loader.load(request); loader.addEventListener(Event.COMPLETE,

getgroupclips);}

Function: getgroupclips(event:Event) gets data from php encoded with , and :

var clips:String = event.target.data;var clipsarray:Array = clips.split(",");var cliptitles:Array = new Array();var clipaddrs:Array = new Array();var clipinfo:Array;var i:int;var num:int;num = clipsarray.length;for(i=0;i<num;i++) {

clipinfo = clipsarray[i].split(":");cliptitles.push(clipinfo[1]);clipaddrs.push(clipinfo[0]);}

… more …

Video example: getgroupclips.php

<?phprequire("opendbq.php");$group = $_GET['group'];$query = "SELECT fileaddr, cliptitle FROM

videoclips2 where clipgroup='" . $group . "'";$result = mysql_query($query); $sendback = "";mysql_close();$num = mysql_num_rows($result);

getgroupclips.php, cont.

$i = 0;while ($i<$num) {$fa = mysql_result($result,$i,"fileaddr");$ct = mysql_result($result,$i,"cliptitle");$sendback = $sendback . "$fa:$ct";$i++;if ($i<$num) {$sendback = $sendback . ","; }}print "$sendback"; ?>

Putting in the colon

Putting in the comma

Grid design example

• Design is list of x, y coordinates and name of symbol in cell at those coordinates

• Sends and receives [long] string that was/will be XML

• Use built-in ActionScript to set up XML and then extract information about the design

Example: function fetchfromdb(ev:Event) sends data (request) to a php file

var request:URLRequest = new URLRequest("fetchdesign.php");var variables:URLVariables = new URLVariables();variables.designname=playersfilename.text;request.data = variables;playersfilename.text ="fetching ";var loader:URLLoader = new URLLoader();loader.load(request);loader.addEventListener(Event.COMPLETE, getfromdb);

Function getfromdb(ev:Event) gets the information back from php

var ds:String = ev.target.data;var dxml:XML = new XML();if (ds.length>4) {

dxml = new XML(ds);restoredesign(dxml); // my function to use the XML }

else { //empty data is 4 bytes long!playersfilename.text = "Design not in database";

}}

fetchdesign.php<?php$des_name = $_REQUEST['designname'];require("opendbq.php");$query="SELECT des_string from designs where

des_name='$des_name'";$result=mysql_query($query);$NoR = @mysql_num_rows($result);if ($NoR>=1) { $sendback = mysql_result($result,0,"des_string"); }else { $sendback = ""; }print $sendback;mysql_close($link);?>

Comments

• The php back to Flash ActionScript uses print or echo.

• The $sendback is my name. It could be anything.

• The stuff sent back is the ev.target.data

• Note: use of the aTa.text field to show you what is going on. This is not necessary in the html to/from php.

Homework

• Practice ! – php to MySQL– ERD, DFD, [Storyboard]

• Check out on-line midterm study guide

• Catch up, review next class.