Javascript Examples :: View topic

starrwriter · 16 Apr 2004

Can anyone tell me how to stop the script below from removing the back slashes in the image URL? Here's the result I get in the alert:

<img src=C:WindowsDesktopimage1.jpg width="100" height="100" border="0">

function getImageDims(imgurl)
{
var oImage = new Image();
oImage.onload = new Function(
'alert("<img src='+imgurl + ' width="+this.width + " height="+this.height + [" border=0>"])'
);
oImage.src = load.value;
}
</script>
</head>
<body>
<input type="file" name="load"> <input type="button" value="Get Image Data" onclick="getImageDims(load.value)">

The URL is displayed correctly with slashes in the <input type="file" text field, but the script changes load.value by removing the slashes.

EricMEvans · 23 Sep 2002

To JavaScript, "\" is a special character referred to as Escapse. It is used to indicate that the next character is something special. So to indicate that the \ is the one you want, you have to escape it like \\. Before you submit if you were to go through and put in \\ wherever there is a \, it would work. This is the same for all C languages.

Yeah, it is a pain to have to go through and manually fix the \ so, to make it easier, you need to use a replace statement as I did below. It uses regular expressions which is a totally different topic. The four slashes are actually two sets of \\.

Code:

<SCRIPT LANGUAGE="JavaScript">
function getImageDims(imgurl)
{
imgurl = imgurl.replace(/\\/g, "\\\\");
var oImage = new Image();
oImage.onload = new Function('alert("<img src='+imgurl + ' width="+this.width + " height="+this.height + [" border=0>"])');
oImage.src = load.value;
}
</script>
</head>
<body>
<input type="file" name="load"> <input type="button" value="Get Image Data" onclick="getImageDims(load.value)">

starrwriter · 16 Apr 2004

EricMEvans wrote:

To JavaScript, "\" is a special character referred to as Escapse. It is used to indicate that the next character is something special. So to indicate that the \ is the one you want, you have to escape it like \\. Before you submit if you were to go through and put in \\ wherever there is a \, it would work. This is the same for all C languages.

Yeah, it is a pain to have to go through and manually fix the \ so, to make it easier, you need to use a replace statement as I did below. It uses regular expressions which is a totally different topic. The four slashes are actually two sets of \\.

Code:

<SCRIPT LANGUAGE="JavaScript">
function getImageDims(imgurl)
{
imgurl = imgurl.replace(/\\/g, "\\\\");
var oImage = new Image();
oImage.onload = new Function('alert("<img src='+imgurl + ' width="+this.width + " height="+this.height + [" border=0>"])');
oImage.src = load.value;
}
</script>
</head>
<body>
<input type="file" name="load"> <input type="button" value="Get Image Data" onclick="getImageDims(load.value)">

That works, but I forgot about the quotes that go around the image URL in an image tag. I'll figure it out. Thanks for your help.

EricMEvans · 23 Sep 2002

Here it is with the other quotes

Code:

<SCRIPT LANGUAGE="JavaScript">
function getImageDims(imgurl)
{
imgurl = imgurl.replace(/\\/g, "\\\\");
var oImage = new Image();
oImage.onload = new Function('alert("<img src=\\"'+imgurl + '\\" width="+this.width + " height="+this.height + [" border=0>"])');
oImage.src = load.value;
}
</script>
</head>
<body>
<input type="file" name="load"> <input type="button" value="Get Image Data" onclick="getImageDims(load.value)">