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garethtnashFlag for United Kingdom of Great Britain and Northern Ireland

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Javascript Image Upload - Image Preview

Hello,

I could do with a little Javascript help please, I found a script that creates a preview of the image file uploaded once the upload has suceeded.... Only it doesn't work.

To be more precise my form has 6 file fields on it (I've only tested against one so far) And I want to run the script for each file upload.

I've encompassed my file fields in a table (I know) with three columns -

1 Label
2 Image (If there)
3 file field

I only want to show (2) if a file has been uploaded.....

The Javacript I found is -

<!-- Begin
  // width to resize large images to
var maxWidth=66;
  // height to resize large images to
var maxHeight=66;
  // valid file types
var fileTypes=["bmp","gif","png","jpg","jpeg"];
  // the id of the preview image tag
var outImage="previewField";
  // what to display when the image is not valid
var defaultPic="spacer.gif";

/***** DO NOT EDIT BELOW *****/

function preview(what){
  var source=what.value;
  var ext=source.substring(source.lastIndexOf(".")+1,source.length).toLowerCase();
  for (var i=0; i<fileTypes.length; i++) if (fileTypes[i]==ext) break;
  globalPic=new Image();
  if (i<fileTypes.length) globalPic.src=source;
  else {
    globalPic.src=defaultPic;
    alert("THAT IS NOT A VALID IMAGE\nPlease load an image with an extention of one of the following:\n\n"+fileTypes.join(", "));
  }
  setTimeout("applyChanges()",200);
}
var globalPic;
function applyChanges(){
  var field=document.getElementById(outImage);
  var x=parseInt(globalPic.width);
  var y=parseInt(globalPic.height);
  if (x>maxWidth) {
    y*=maxWidth/x;
    x=maxWidth;
  }
  if (y>maxHeight) {
    x*=maxHeight/y;
    y=maxHeight;
  }
  field.style.display=(x<1 || y<1)?"none":"";
  field.src=globalPic.src;
  field.width=x;
  field.height=y;
}
// End -->

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I'm calling the javacript action like -

      <tr>
        <td class="fixedleftwidth">Main Image <span class="asterix">*</span></td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField" src="spacer.gif"></td>
        <td><input type="file" name="image1" id="image1" onchange="preview(this)"/></td>
      </tr>

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This currently uses a spacer image as the default, it it not possible to have - no image?

So for my 6 uploads my code looks like -

<table border="0" cellspacing="0" cellpadding="0" class="newproducttable">
      <tr>
        <td class="fixedleftwidth">Main Image <span class="asterix">*</span></td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField" src="spacer.gif"></td>
        <td><input type="file" name="image1" id="image1" onchange="preview(this)"/></td>
      </tr>
      <tr class="alternativerowtr">
        <td class="fixedleftwidth">Second Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField2" src="spacer.gif" /></td>
        <td><input type="file" name="image2" id="image2" /></td>
      </tr>
      <tr>
        <td class="fixedleftwidth">Third Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField3" src="spacer.gif" /></td>
        <td><input type="file" name="image3" id="image3" /></td>
      </tr>
      <tr class="alternativerowtr">
        <td class="fixedleftwidth">Fourth Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField4" src="spacer.gif" /></td>
        <td><input type="file" name="image4" id="image4" /></td>
      </tr>
      <tr>
        <td class="fixedleftwidth">Fifth Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField5" src="spacer.gif" /></td>
        <td><input type="file" name="image5" id="image5" /></td>
      </tr>
      <tr class="alternativerowtr">
        <td class="fixedleftwidth">Sixth Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField6" src="spacer.gif" /></td>
        <td><input type="file" name="image6" id="image6" /></td>
      </tr>
    </table>

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Appreciate your help - thank you
Avatar of leakim971
leakim971
Flag of Guadeloupe image

>This currently uses a spacer image as the default, it it not possible to have - no image?
<img alt="Graphic will preview here" id="picField" src="spacer.gif">

Replace spacer.gif by no_image_4.gif
Avatar of garethtnash

ASKER

Hello Again :)

Like the jsfiddle resource :)

Tried loading a file in Main Image filefield, but I still see the No image available graphic?

Haven't got a clue where to start with this?

Thank you
I suppose you don't want flash and have the preview before uploading the image?

if yes, there's no solution to this problem until you want a solution for a specific browser or accept a third party technology :
- IE+ActiveX
- FF+addon
- Any browsers+AdobFlash
- Any browsers+Applet
Hi, I was hoping to do this in javacript,. is there a better option? if so can you point me in the right direction..

Thank you
try:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
 "http://www.w3.org/TR/html4/loose.dtd">

<html>
<head>
<title></title>
<style type="text/css"><!--
#picField,#picField1,#picField2,#picField3,#picField4,#picField5,#picField6 {
    width:64px;
}
.hideMe{display:none;}
-->
</style>
<script type="text/javascript"><!-- Begin
  // width to resize large images to
var maxWidth=66;
  // height to resize large images to
var maxHeight=66;
  // valid file types
var fileTypes=["bmp","gif","png","jpg","jpeg"];
  // the id of the preview image tag
var outImage="previewField";
  // what to display when the image is not valid
var defaultPic="spacer.gif";

/***** DO NOT EDIT BELOW *****/
var globalPic;
function preview(what){
  var source=what.value;
  var ext=source.substring(source.lastIndexOf(".")+1,source.length).toLowerCase();
  for (var i=0; i<fileTypes.length; i++) if (fileTypes[i]==ext) break;
  globalPic=new Image();
  if (i<fileTypes.length) globalPic.src=source;
  else {
    globalPic.src=defaultPic;
    alert("THAT IS NOT A VALID IMAGE\nPlease load an image with an extention of one of the following:\n\n"+fileTypes.join(", "));
  }
  outImage='picField'+what.id.replace(/\D/g,'');
  setTimeout("applyChanges('"+outImage+"')",200);
}

function applyChanges(outImage){
  var field=document.getElementById(outImage);
  var x=parseInt(globalPic.width);
  var y=parseInt(globalPic.height);
  if (x>maxWidth) {
    y*=maxWidth/x;
    x=maxWidth;
  }
  if (y>maxHeight) {
    x*=maxHeight/y;
    y=maxHeight;
  }
  field.style.display=(x<1 || y<1)?"none":"";
  field.src=globalPic.src;
  field.width=x;
  field.height=y;
  document.getElementById(outImage).className="";
}
// End -->
</script>
</head>
<body>
<table border="0" cellspacing="0" cellpadding="0" class="newproducttable">
      <tr>
        <td class="fixedleftwidth">Main Image <span class="asterix">*</span></td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField1" src="#" class="hideMe"></td>
        <td><input type="file" name="image1" id="image1" onchange="preview(this)"/></td>
      </tr>
      <tr class="alternativerowtr">
        <td class="fixedleftwidth">Second Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField2" src="#" class="hideMe" /></td>
        <td><input type="file" name="image2" id="image2" onchange="preview(this)"/></td>
      </tr>
      <tr>
        <td class="fixedleftwidth">Third Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField3" src="#" class="hideMe" /></td>
        <td><input type="file" name="image3" id="image3" onchange="preview(this)"/></td>
      </tr>
      <tr class="alternativerowtr">
        <td class="fixedleftwidth">Fourth Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField4" src="#" class="hideMe" /></td>
        <td><input type="file" name="image4" id="image4" onchange="preview(this)"/></td>
      </tr>
      <tr>
        <td class="fixedleftwidth">Fifth Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField5" src="#" class="hideMe" /></td>
        <td><input type="file" name="image5" id="image5" onchange="preview(this)"/></td>
      </tr>

       <tr class="alternativerowtr">
        <td class="fixedleftwidth">Sixth Image (Optional)</td>
        <td class="img-preview-column"><img alt="Graphic will preview here" id="picField6" src="#" class="hideMe" /></td>
        <td><input type="file" name="image6" id="image6" onchange="preview(this)"/></td>
      </tr>

    </table>
</body>
</html>

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You need to upload the file before having the preview
Applet, ActiveX, Flash (with Javascript or not) allow you to have the preview without uploading first
@garethtnash:
I don't know where you got that script from, but I hope it was stated clearly that it was meant just for IE.  For other browsers you will need to upload the image first.

>>You need to upload the file before having the preview
The above works fine for IE because I provides the full path to the image file instead of just the filename.
Thanks both, i guess this is an idea for the bin then?
ASKER CERTIFIED SOLUTION
Avatar of hielo
hielo
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Thank you