What is this "FF" meaning ?
When I was posting a form this char make submits errors.
the FF character is a Form Feed character. See this answer for details on the distinctions between CR (Carriage Return) LF (Line Feed) and FF
Related
I have the following code
<td colspan="#missingGridColumnCount">** <span translate="MissingItems">.MissingInstruments</span> **</td>
This prints correctly through the browser but when I print to my Zebra printer, I get the following on the label:
**_áMissing Items_á**
I have looked through Zebra Label documentation but cannot find a way to convert this or accept the for the labels.
This is a character encoding issue.
The probable chain of events is this:
The browser is rendering the entity into the Unicode code point "U+00A0 NO-BREAK SPACE".
This is being encoded in UTF-8, as the sequence of bytes C2 A0.
These bytes are being interpreted by the Zebra printer according to Code page 850, where C2 is mapped to "┴" (U+2534 BOX DRAWINGS LIGHT UP AND HORIZONTAL) and A0 to "á" (U+00E1 LATIN SMALL LETTER A WITH ACUTE).
In code page 850, a non-breaking space is represented by the byte FF.
You may be able to tell the whatever is interpreting the HTML to use Code page 850 instead of UTF-8, and it will send the byte sequences the printer is expecting. You will need to make sure your input doesn't contain any literal UTF-8 - escape all non-ASCII characters as HTML entities.
Otherwise, you will need to substitute byte-wise before sending to the printer, or encode in some other way.
We have a record in SQL database, which contains a ASCII 26 character:
SELECT char(26)
From the looking, it's like a arrow, which we can see it in the Eclipse debugging. However, when we try to output it to HTML front-end, it just skipped that character. What's more strange is, the arrow does appear in page source.
It seems 26 belongs to control characters. So is it possible to display the arrow in HTML? Why some place like the debugging window of Eclipse can show it well?
It's a control character, unprintable by definition. Some character sets (or fonts, not sure which determines that) do print control characters; Unicode is not one of them. See Browser Test Page for Unicode Character 'SUBSTITUTE' (U+001A).
Decide what you actually want to display, and replace this character with an actually printable Unicode character.
You could for example use →, →, Unicode Character 'RIGHTWARDS ARROW' (U+2192).
In JSP file, the source code is
|13|<%="\u0031\u0080\u0033" %>|
The result on the page is:
|1€3|13|
Why is the Euro symbol represented differently ?
The HTML numerical character references in the range 0x80–0x9F don't actually correspond to the characters U+0080–U+009F. Instead, they refer to the characters mapped into the bytes 0x80–0x9F from the windows-1252 encoding.
This is a weird historical artefact from the days before browsers did Unicode. HTML5 sort-of standardises it, in that although it's invalid parsers are required to parse it this way. This does not happen in XML/XHTML.
So \u0080 gives you the actual character U+0080, which you can't see because it's an invisible control character, but gives you code page 1252 byte 0x80, which is U+20AC Euro Sign.
This question has bothered me for a million years... whenever I create a website with a textarea that allows multi-line (such as a "Bio" for a user's profile) I always end up writing the following paranoid code:
// C# code sample...
bio = bio.Replace("\r\n", "\n").Replace("\r", "\n");
bio = Regex.Replace(#"\n{2,}", "\n\n");
So, what do browsers send up for a <textarea name="Bio"></textarea> if it has multiple lines?
The HTTP and MIME specs specify that header lines must end with \r\n, but they aren't clear (some would argue that it isn't clear if they are clear) about what to do with the contents of a TEXTAREA. (See, for instance, this thread from an HTML working group about the issue.)
Here's a quote from the HTTP/1.1 spec about message headers:
The line terminator for message-header fields is the sequence CRLF. However, we recommend that applications, when parsing such headers, recognize a single LF as a line terminator and ignore the leading CR.
I think that is a good strategy in general: be strict about what you produce but liberal in what you accept. You should assume that you will receive all sorts of line terminators. (Note that in addition to CRLF and LF, Mac OS-9 used CR alone, and there are still a few of those around. The Unicode standard (section 5.8) specifies a wide range of character sequences that should be recognized as line terminators; there's a list of them here.)
what do browsers send up for a <textarea></textarea> if it has multiple lines?
All modern browsers send CRLF (\r\n). However this is not something that has been satisfactorily standardised so I would definitely consider it worthwhile to normalise the newlines of all multi-line input text.
When the value is read through JavaScript rather than being submitted directly from a form, browser behaviour differs. IE and Opera return strings with CRLFs in; Firefox and WebKit return LF. So any form that gets submitted with JavaScript/XMLHttpRequest help is likely to come in either form.
In html made by fckeditor i find the following character:
What is this character?
Looks like the ASCII code for Carriage Return, encoded as an XML character reference.
When you code in windows, and use "DOS/Windows" line endings, the your lines will end like this "\r\n".
In some xhtml editors, that "\r" is illegal so te editor converts it to "
".