| Nr | Description |
| 1 |
Anchor object |
| 2 |
Error message (HTML format) |
| 3 | Explanation of the error (HTML format) |
If the HTML file contains a separate message line
<div class="messagearea"></div>
the output is not in the form of a pop-up, but in this message line. If you have specified an explanation as the third parameter, the output is always a pop-up.
Both the message and the explanation are interpreted as HTML text, so you can use any HTML formatting.
HTML and JavaScript code for the example above:
<button type="button" class="button" onclick="upload_image(this, 'file_input')">
Upload
</button>
<input type="file" id="file_input" style="width:400px" accept="image/*" />
<script>
function upload_image(f, id) {
// <input> element
var h = document.getElementById(id);
if (h.files.length == 0) return;
if (h.files[0].size > 4*1024*1024) {
var msg = "Image file too large; the maximum size is 4MB."
+ "<br><br>"
+ "Your file has the size "
+ stringFileSize(h.files[0].size);
S10ErrorMessage(f, msg);
};
<!– upload image -->
…
}
function stringFileSize(number) {
if (number < 1024) return number + 'bytes';
number = number / 1024;
if (number < 1024) return number.toFixed(1) + 'KB';
number = number / 1024;
return number.toFixed(1) + 'MB';
}
</script>