Generating image on the same page!

ivoilic · March 2, 2012

Ok so I have a file called balancer.php which contain the basic html code for a form. In the same file I have php code that requests the info which it uses to generate an image based on the info from the form. Everything works fine except that I can't seem to figure out how to get the image to display alongside the original form. It always appears in a new blank page. As of now I am unsure of what method to use to generate the image on the same page.

Here is the start of my form (the options are not relevant):

<form method="post" action="Balancer.php">
<input name="Craft" type="submit" id="Craft" />
</form>

Here is the output of the php:

// tell the browser that the content is an image
header('Content-type: image/png');
// output image to the browser
imagepng($image_f);

What do I need to change and add in order to have the image display next to the form (preferably without reloading the page)?

I'm a noob... small words...please...

laffin · March 2, 2012

Quick note: anytime the phrase "no refresh/reload" with dynamic content than your looking at javascript/ajax/jquery

you cant display an image from the html processing script, they have to remain seperate scripts (your html output script & your image script)

using js to detect a change on your form to update the image itself

ivoilic · March 2, 2012

So I have been messing around with code that I got here: http://www.w3schools.com/ajax/ajax_aspphp.asp

I am trying to change it up so it displays the image, here is the js file:

// JavaScript Document
function displaycard(str)
{
var xmlhttp;
if (str.length==0)
  {
  document.getElementById("bla").innerHTML="";
  return;
  }
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("bla").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","balancer.php"+str,true); //Confused what should go here
xmlhttp.send();
}

I still confused on parts of the code...

I have this button at the end of my form

  <button type="button" onclick="displaycard(this.value)">Craft</button>

I know there is a lot wrong with this. I was wondering if I could get some help with it.

Any help at all would be amazing!!

PFMaBiSmAd · March 2, 2012

See this link - http://p2p.wrox.com/book-professional-ajax-isbn-978-0-471-77778-6/48331-ajax-get-dynamic-images.html

ivoilic · March 2, 2012

Thanks for the link PFMaBiSmAd

I tried using some of the code from the link but I get the broken link symbol where the image should be (paper ripped in half).

Here is the java/html:

<head>
<script language="javascript" type="text/javascript">
function ajaxFunction(){  
    var xmlHttp;
      try{    // Firefox, Opera 8.0+, Safari    
        xmlHttp=new XMLHttpRequest();
    }
      catch (e){    // Internet Explorer    
        try{      
            xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (e){      
            try{
                xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
            }
              catch (e){
                alert("Your browser does not support AJAX!");
                return false;
            }
        }
    }
    xmlHttp.onreadystatechange=function()
      {
      if(xmlHttp.readyState==4)
        {
            document.getElementById("response").innerHTML=xmlHttp.responseText;
            var img = document.createElement('img');
            img.onload = function (e) {
                document.getElementById("imgHolder").width=this.width;
                document.getElementById("imgHolder").height=this.height;
                document.getElementById("imgHolder").src=this.src;
            }
            img.onerror = function(e){
                alert("Error processing Image.  Please try again.")
            }
            img.src = xmlHttp.responseText;
        }
      }
      
    sendVars="tx="+document.forms["myForm"]["txtTxt"].value;
    sendVars+="&fon=ARIAL.TTF";
    sendVars+="&sz="+document.forms["myForm"]["txtSz"].value;
    sendVars+="&fg="+document.forms["myForm"]["txtFG"].value;;
    sendVars+="&bg="+document.forms["myForm"]["txtBG"].value;;

    xmlHttp.open("POST","Test.php",true);
    xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); //include this for post or it won't work!!!!
    xmlHttp.send(sendVars);  
}
</script>
</head>
<body>
<form name="myForm">
text: <input type="text" name="txtTxt" /><br/>
size: <input type="text" name="txtSz" /><br/>
fg: <input type="text" name="txtFG" /><br/>
bg: <input type="text" name="txtBG" /><br/>
</form>
<img src="" id="imgHolder"/>
<a href="javascript:ajaxFunction()">Send!</a>
</body>
</html>

Here is the php:

<?php
$id= ("imgHolder");
$tx=$_POST["tx"];
$fon=$_POST["fon"];
$sz=$_POST["sz"];
$fg=$_POST["fg"];
$bg=$_POST["bg"];
$pad=0;

$imX=imagettfbbox($sz,0,$fon,$tx); //get bounding box for dimensions
$imDim=imgSize($imX, 0); //run a function to get image size

$im=imagecreate($imDim["w"], $imDim["h"]); //create new image

$bgCol=hex2rgb($bg); //convert bg color from hex to rgb
$bgColor=imagecolorallocate($im,$bgCol['r'],$bgCol['g'],$bgCol['b']); //allocate bg color

$fgCol=hex2rgb($fg); //convert fg color from hex to rgb
$fgColor=imagecolorallocate($im,$fgCol['r'],$fgCol['g'],$fgCol['b']); //allocate fg color

imagettftext ($im, $sz, 0,0, imagesy($im)-$imDim["bl"], $fgColor, $fon, $tx); //print the text

imagejpeg($im,$id.".jpg", 100); //create and save the image
echo $id.".jpg"; //Return Id of pic to javascript

//===============================================================================
function imgSize($bb, $pad){
    //a function to interpret the bounding box info here.

    $imgDim=array("w"=>$w,"h"=>$h,"bl"=>$blOff);
    return($imgDim);
}
function hex2rgb($hex) {
        return array( 'r' => hexdec(substr($hex, 0, 2)), // 1st pair of digits
                      'g' => hexdec(substr($hex, 2, 2)), // 2nd pair
                      'b' => hexdec(substr($hex, 4, 2))  // 3rd pair
                    );
    }


?>

What am I doing wrong!?!? :confused:

ivoilic · March 2, 2012

I also tried the second method and got this message:

Warning: imagepng() [function.imagepng]: Unable to open 'img/sdfsa+MJoa.png' for writing: No such file or directory in /Library/WebServer/Documents/temp/test2.php on line 70

Here is the html file:

<html>
<head>
<title>Ajax with jQuery Example</title>
<script type="text/JavaScript" src="jquery.js"></script>
<script type="text/JavaScript">



$(document).ready(function(){

$("#generate").click(function() { loadImage(); });

function loadImage(){

    var inputString = $("#inputString").val();

    var inputFont = $("#inputFont option:selected").val();

        $("#image p").load("test2.php?text=" + inputString + "&font=" + inputFont)

}
});

</script>
<style type="text/css">
   #wrapper {
     margin-top: 30px;
     height: 50px;
     width: 600px;
     border: 1px solid black;
     text-align: center;
   }
   #image {
       padding-bottom: 80px;
       border-style: none;
       height: 100px;
       width: 600px;
       text-align: center;
   }
</style>
</head>
<body>
   <center><div id="image"><p> </p></div>
     <div id="wrapper">
    Engraved Text:<input size="30" id="inputString" type="text" />
    Font:<select id="inputFont">
  <option value="balmo">Balmoral</option>
  <option value="clar">Clarendon</option>
  <option value="curlz">Curlz</option>
  <option value="english">Old English</option>
  <option value="freehand">Freehand</option>
  <option value="greek">Greek</option>
  <option value="interlock">Interlocking Monogram</option>
  <option value="MJoa">Times</option>

<!--   
<option value="3">Cool Engraving</option>
<option value="3">Cool Engraving</option>
<option value="3">Cool Engraving</option>
<option value="3">Cool Engraving</option>
<option value="3">Cool Engraving</option>
-->
    </select>
    <input type="submit" id="generate" value="Generate!">
</div>
</center>
</body>
</html>

Here is the php:

<?php

// VARIABLES   ############################################################################

// The text to draw
$text = $_GET['text'];
//$text = 'poopie';

// Font File, don't need a slash if file is in same dir as php file
$font = $_GET['font'];
//$font = '1';

//size in PTS
$size = 78;

//Angle
$angle = 0;

//Width of Canvas
$width = 500;

//Height of Canvas
$height = 200;

//Text Bounding Box Dimensions
$tb = imagettfbbox($size, $angle, $font, $text);

/*
Output of imagettfbbox is an array as follows:

Array
(
    [0] => 0 // lower left X coordinate
    [1] => -1 // lower left Y coordinate
    [2] => 198 // lower right X coordinate
    [3] => -1 // lower right Y coordinate
    [4] => 198 // upper right X coordinate
    [5] => -20 // upper right Y coordinate
    [6] => 0 // upper left X coordinate
    [7] => -20 // upper left Y coordinate
)
*/

// Centering Function  #####################################################################

// X Position Calculated by subtracting width of Text Bounding Box from total canvas width
$posx = ceil(($width - $tb[2]) / 2);

// Y Position Calculated by subtracting height of Text Bounding Box from total canvas height
$posy = ceil(($height - $tb[5]) / 2);

// Creating Image File
$im = imagecreatetruecolor($width, $height);

// State Colors available to Image File
$white = imagecolorallocate($im, 255, 255, 255);
$grey = imagecolorallocate($im, 128, 128, 128);
$black = imagecolorallocate($im, 0, 0, 0);

imagefilledrectangle($im, 0, $angle, $width, $height, $white);

// Add the text
imagettftext($im, $size, $angle, $posx, $posy, $black, $font, $text);

// Usage of imagettftext()
// array imagettftext  ( resource $image  , float $size  , float $angle  , int $x  , int $y  , int $color  , string $fontfile  , string $text  ) //

$file= "$text+$font.png";

imagepng($im, "img/$file");
imagedestroy($im);

$imgloc= "img/$file";

echo "<img src=$imgloc>";

?>

I changed one of the fonts to use my font and I installed jquery.

What is wrong here???

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Generating image on the same page!

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