Cooking With Web Services: PHP & GD - Example Walkthrough
(Page 4 of 5 )
The Problem:
We have to develop a web application, which shows its visitors the current temperature of capital cities of each state from the West coast to the East coast of the continental United States. Let’s, for simplicity sake, draw an imaginary line through each capital of the following states: California (CA), Nevada (NV), Utah (UT), Colorado (CO), Nebraska (NE), Iowa (IA), Illinois (IL), Indiana (IN), Ohio (OH), Pennsylvania (PA), New Jersey (NJ) and New York (NY), and also pick any zip code from the capital city of each state.
So the visitor will see the following information:
Step 1:
Find service according to your need:
Let’s find some Web Services, which provide current temperature by region; in our case by zip code. I chose a service from www.xmethods.net and have planned to use service names “Weather-Temperature”, which is an RPC style service and implemented with Apache SOAP; and the service developed using Java.
Note: Remote Procedure Call (RPC)-Style Web Services are synchronous because the clients invoke the Web Service by sending parameters and waits for the method to return values before continuing. RPC-style Web Services are tightly coupled because the sending parameters and return values are as described in WSDL (Web Service Description Language) file, an XML format for describing Web Services. In RPC-style Web Services, the calling parameters and the return values are wrapped inside the SOAP Body.
Step 2:
The service endpoint is http://services.xmethods.net:80/soap/servlet/rpcrouter. Let’s analyze the WSDL (Web Service Description Language) file:
Step 3:
Invoke the Web Service:
<?php
// include the NuSOAP classes
require ('nusoap.php');
$zipW2E='94203:89702:84102:80203:68501:50301:62701:46201:
43085:17101:08601:12201';
$arrZip=split(":",$zipW2E);
//Create SOAP client
$s=new soapclient('http://www.xmethods.net/sd/2001/TemperatureService.wsdl'
,'wsdl');
for ($i=0;$i < count($arrZip);$i++)
{
$v=$arrZip[$i];
$parameters=array($v);
//Make the RPC call to get temperature for each zip code selected in the array
$graphValues[$i]=$s->call('getTemp',$parameters);
}
// array of states we want to show
$States=array('CA','NV','UT','CO','NE','IA','IL','IN','OH','PA','NJ','NY');
…
?>
Step 4:
Plotting data using PHP GD.
<?php
// Define JPEG image
header('Content-type: image/jpeg');
// Define image size and width
$imgWidth=350;
$imgHeight=350;
// Create image and define colors
$image=imageCreate($imgWidth, $imgHeight);
$colorWhite=imageColorAllocate($image, 0xFF, 0xFF, 0xFF);
$colorGrey=imageColorAllocate($image, 0xEE, 0xEE, 0xEE);
$colorDarkBlue=imageColorAllocate($image, 0xFF, 0xFF, 0xFF);
$colorLightBlue=imageColorAllocate($image, 0x00, 0x00, 0xFF);
$black = ImageColorAllocate($image,0,0,0);
$red = ImageColorAllocate($image,0xFF,0,0);
// Create border around image
imageLine($image, 0, 0, 0, 300, $colorGrey);
imageLine($image, 0, 0, 300, 0, $colorGrey);
imageLine($image, 299, 0, 299, 299, $colorGrey);
imageLine($image, 0, 299, 299, 299, $colorGrey);
// Draw the grid for better look
for ($i=1; $i <= 12; $i++){
imageLine($image, $i*25, 0, $i*25, 305, $colorGrey);
imageLine($image, 0, $i*25, 305, $i*25, $colorGrey);
}
//show line graph
for ($i=0; $i<12; $i++) {
//uncomment follwing line to see the line graph
//imageLine($image, $i*25, (299-$graphValues[$i]*3), ($i+1)*25, (300-$graphValues[$i+1]*3), $red);
}
// Create bar charts and scale it
for ($i=0; $i<12; $i++){
$gV=$graphValues[$i]*3;
if ($gV > 300) {
$gv=300;
}
//comment following 2 lines to see only line chart
//imageFilledRectangle($image, $i*25, (300-$gV), ($i+1)*25, 300, $colorDarkBlue);
//imageFilledRectangle($image, ($i*25)+1, (300-$gV)+1, (($i+1)*25)-5, 298, $colorLightBlue);
}
// Output graph and clear image from memory
//
$x1=0;
$x2=0;
for ($i=0;$i<count($States);$i++){
ImageString($image,2,$x1,305,''.round($graphValues[$i]).'',$black);
ImageString($image,2,$x2,320,''.$States[$i],$black);
$x1=$x1+25;
$x2=$x2+25;
}
//output image
imageJPEG($image);
//cleanup
imageDestroy($image);
Step 5:
Put it all together:
<?php
require ('nusoap.php');
$zipW2E='94203:89702:84102:80203:68501:50301:62701:46201:
43085:17101:08601:12201';
$arrZip=split(":",$zipW2E);
$s=new soapclient('http://www.xmethods.net/sd/2001/TemperatureService.wsdl','wsdl');
for ($i=0;$i < count($arrZip);$i++)
{
$v=$arrZip[$i];
$parameters=array($v);
$graphValues[$i]=$s->call('getTemp',$parameters);
}
$States=array('CA','NV','UT','CO','NE','IA','IL','IN','OH','PA','NJ','NY');
header('Content-type: image/jpeg');
$imgWidth=350;
$imgHeight=350;
$image=imageCreate($imgWidth, $imgHeight);
$colorWhite=imageColorAllocate($image, 0xFF, 0xFF, 0xFF);
$colorGrey=imageColorAllocate($image, 0xEE, 0xEE, 0xEE);
$colorDarkBlue=imageColorAllocate($image, 0xFF, 0xFF, 0xFF);
$colorLightBlue=imageColorAllocate($image, 0x00, 0x00, 0xFF);
$black = ImageColorAllocate($image,0,0,0);
$red = ImageColorAllocate($image,0xFF,0,0);
imageLine($image, 0, 0, 0, 300, $colorGrey);
imageLine($image, 0, 0, 300, 0, $colorGrey);
imageLine($image, 299, 0, 299, 299, $colorGrey);
imageLine($image, 0, 299, 299, 299, $colorGrey);
for ($i=1; $i <= 12; $i++){
imageLine($image, $i*25, 0, $i*25, 305, $colorGrey);
imageLine($image, 0, $i*25, 305, $i*25, $colorGrey);
}
for ($i=0; $i<12; $i++) {
imageLine($image, $i*25, (299-$graphValues[$i]*3), ($i+1)*25, (300-$graphValues[$i+1]*3), $red);
}
for ($i=0; $i<12; $i++){
$gV=$graphValues[$i]*3;
if ($gV > 300) {
$gv=300;
}
imageFilledRectangle($image, $i*25, (300-$gV), ($i+1)*25, 300, $colorDarkBlue);
imageFilledRectangle($image, ($i*25)+1, (300-$gV)+1, (($i+1)*25)-5, 298, $colorLightBlue);
}
$x1=0;
$x2=0;
for ($i=0;$i<count($States);$i++){
ImageString($image,2,$x1,305,''.round($graphValues[$i]).'',$black);
ImageString($image,2,$x2,320,''.$States[$i],$black);
$x1=$x1+25;
$x2=$x2+25;
}
imageJPEG($image);
imageDestroy($image);
?>
Next: Conclusion >>
More Web Services Articles
More By Ahm Asaduzzaman
