I created a simple test page on my website www.xaisoft.com and it had no errors, but it came back with the following warning and I am not sure what it means.
The Unicode Byte-Order Mark (BOM) in UTF-8 encoded files is known to cause problems for some text editors and older browsers. You may want to consider avoiding its use until it is better supported.
To find out what the BOM is, you can take a look at the Unicode FAQ (quoting) :
Q: What is a BOM?
A: A byte order mark (BOM) consists of
the character code U+FEFF at the
beginning of a data stream, where it
can be used as a signature defining
the byte order and encoding form,
primarily of unmarked plaintext files.
Under some higher level protocols, use
of a BOM may be mandatory (or
prohibited) in the Unicode data stream
defined in that protocol.
Depending on your editor, you might find an option in the preferences to indicate it should save unicode documents without a BOM... or change editor ^^
Some text editors - notably Notepad - put an extra character at the front of the text file to indicate that it's Unicode and what byte-order it is in. You don't expect Notepad to do this sort of thing, and you don't see it when you edit with Notepad. You need to open the file and explicitly resave it as ANSI. If you're using fancy characters like smart quotes, trademark symbols, circle-r, or that sort of thing, don't. Use the HTML entities instead.
Related
I am building a ASP.NET webservice loading other webpages and then hand it clients.
I have been doing quite well with character code treatment, reading the meta tag from HTML then use that codeset to read the file.
But nevertheless, some less educated users just don't understand code sets. They declare a specific encoding method e.g. "gb2312", but in fact, he is just using normal UTF8. When I use gb2312 to decode the text, everything turns out a holy mess.
How can I detect whether the text is properly decoded? I loaded that page into my IE, which correctly use UTF-8 to decode the page. How does it achieve that?
Based on the BOM you can tell what encoding is used.
BOM and encoding
If you want to detect character set you could use the C# port of mozilla's character set detector.
CharDetSharp
If you want to make it extra sure that you are using a correct one, you maybe could be looking for special characters that are not supposed to be there. It is not very likely to include "óké". So you could be looking for such characters and try to use different encoding/character set to process your file.
Actually it is really hard to make your application completely "fool-proof".
Trying to create custom types, aspects and properties for Alfresco, I followed the Alfresco Developer Series guide. When I reached the localization section I found out that Alfresco does not handle UTF-8 encoding in the .properties files that you create. Greek characters are not displayed correctly in Share.
Checking out other built-in .properties files (/opt/alfresco-4.0.e/tomcat/webapps/alfresco/WEB-INF/classes/alfresco/messages) I noticed that in Japanese, for example, the characters are in this notation: \u3059\u3079\u3066\u306e...
So, the question is: do I have to convert the greek words in the above mentioned notation for Share to display them correctly, or is there another -more elegant- way to do it?
The \u#### form is the Java form of the Unicode Escape Sequence, and is used to reference unicode characters without having to worry about the encoding of the file storing them.
This question has some information on how to create and decode them
Another way, which is what Alfresco developers tend to use, is the Native2ASCII tool which ships with Java itself. With that, you can initially write your strings in a UTF-8 (for example) file, then use the tool to turn them into their escaped form.
Someone in email sent me letters like this
IVIØR†€™
correct should be
IVIØR†€™
suppose to be
How do I represent them in their original Portuguese langauge, it got altered after being passed through HTTP GET request.
I probably will not be able to fix the site.. but maybe create a repair tool to repair these broken encoded letters? or anyone know of any repair tool? or how to do it manually by hand? Seems like nothing is lost.. just badly interpreted
What happened here is that UTF-8 got misinterpreted as ISO-8859-1; and then other kinds of mangling (the bad ISO-8859-1 string being re-UTF-8-encoded; the non-breaking space character '\xA0' being converted to regular space '\x20') seem to have happened afterward, though those may just be a result of pasting it into Stack Overflow.
Due to the subsequent mangling, there's no really good way to completely undo it, but you can largely undo it by passing it through a not-very-strict UTF-8 interpreter. For example, if I save "IVIØR†€™" as a text-file on my computer, using Notepad, with the "ANSI" (single-byte) encoding, and then I open it in Firefox and tell it to interpret it as UTF-8 (Firefox > Web Developer > Character Encoding > Unicode (UTF-8)), then it displays "IVIØR� €™". (The "�" is because of the '\xA0' having been changed to '\x20', which broke the UTF-8 encoding.)
They're probably not broken. It's just a difference between the encoding they were sent in, vs. the decoding you're viewing them in.
Figure out what encoding was originally used, and use the same one to decode it, and it should look like the original. In terms of writing a "fix-it" tool, you'd always need to know what encoding they were originally created in, which can be complicated depending on the source, and whether or not you have access to said information.
If i have a HTML page with setting to be UTF-8.
and then I input Chinese characters with encoding big5 in the form and submit.
what encoding it is at server side ?
is it automatically converted to UTF-8?
Or how it works ??
Thanks!
Supplement1:
Actually i am really not sure, why the browser can decide which encoding to use ? since the encode was generated by IME. for example: the tool i used to input Chinese character, right ?
supplement2:
if everything just like what "Michael Madsen" said at the below response, then how can asp.net handle this, such that whatever and no matter how i input the characters in the forms, it will not get corrupted always but jsp can't?
The browser works with Unicode - when the characters are typed in there, they're internally stored as Unicode. When the form is submitted, it outputs the characters in whatever encoding is appropriate - usually the encoding of the page.
If you're talking about copy/pasting from a Big5 document, then it will already have been converted to Unicode when it's inserted into the clipboard - maybe even when the document is loaded, depending on your editor.
If you're talking about using some IME to input the characters, the question is kind of faulty, since your IME should be working exclusively with Unicode and Big5 encoding is therefore never involved. If it is, then there's some layer inbetween doing the conversion to/from Unicode anyway, so regardless of that part, the browser never knows the source encoding.
The browser can send up its post in big5 if it wants to, and the server should be able to handle that. But what do you mean by "I input Chinese characters with encoding big5 in the form"? When you input the characters, it's up to the browser to decide which encoding to use, surely?
Has anyone had experience generating files that have filenames containing non-ascii international language characters?
Is doing this an easy thing to achieve, or is it fraught with danger?
Is this functionality expected from Japanese/Chinese speaking web users?
Should file extensions also be international language characters?
Info: We currently support multilanguage on our site, but our filenames are always ASCII. We are using ASP.NET on the .NET framework. This would be used in a scenario where international users could choose a common format and name for there files.
Is this functionality expected from Japanese/Chinese speaking web users?
Yes.
Is doing this an easy thing to achieve, or is it fraught with danger?
There are issues. If you are serving files directly, or otherwise have the filename in the URL (eg.: http://www.example.com/files/こんにちは.txt -> http://www.example.com/files/%E3%81%93%E3%82%93%E3%81%AB%E3%81%A1%E3%81%AF.txt), you're generally OK.
But if you're serving files with the filename generated by the script, you can have problems. The issue is with the header:
Content-Disposition: attachment;filename="こんにちは.txt"
How do we encode those characters into the filename parameter? Well it would be nice if we could just dump it in in UTF-8. And that will work in some browsers. But not IE, which uses the system codepage to decode characters from HTTP headers. On Windows, the system codepage might be cp1252 (Latin-1) for Western users, or cp932 (Shift-JIS) for Japanese, or something else completely, but it will never be UTF-8 and you can't really guess what it's going to be in advance of sending the header.
Tedious aside: what does the standard say should happen? Well, it doesn't really. The HTTP standard, RFC2616, says that bytes in HTTP headers are ISO-8859-1, which wouldn't allow us to use Japanese. It goes on to say that non-Latin-1 characters can be embedded in a header by the rules of RFC2047, but RFC2047 explicitly denies that its encoded-words can fit in a quoted-string. Normally in RFC822-family headers you would use RFC2231 rules to embed Unicode characters in a parameter of a Content-Disposition (RFC2183) header, and RFC2616 does defer to RFC2183 for definition of that header. But HTTP is not actually an RFC822-family protocol and its header syntax is not completely compatible with the 822 family anyway. In summary, the standard is a bloody mess and no-one knows what to do, certainly not the browser manufacturers who pay no attention to it whatsoever. Hell, they can't even get the ‘quoted-string’ format of ‘filename="..."’ right, never mind character encodings.
So if you want to serve a file dynamically with non-ASCII characters in the name, the trick is to avoid sending the ‘filename’ parameter and instead dump the filename you want in a trailing part of the URL.
Should file extensions also be international language characters?
In principle yes, file extensions are just part of the filename and can contain any character.
In practice on Windows I know of no application that has ever used a non-ASCII file extension.
One final thing to look out for on systems for East Asian users: you will find them typing weird, non-ASCII versions of Latin characters sometimes. These are known as the full-width and half-width forms, and are designed to allow Asians to type Latin characters that line up with the square grid used by their ideographic (Han etc.) characters.
That's all very well in free text, but for fields you expect to parse as Latin text or numbers, receiving an unexpected ‘４２’ integer or ‘．ｔｘｔ’ file extension can trip you up. To convert these ‘compatibility characters’ down to plain Latin, normalise your strings to ‘Unicode Normal Form NFKC’ before doing anything with them.
Refer to this overview of file name limitations on Wikipedia.
You will have to consider where your files will travel, and stay within the most restrictive set of rules.
From my experience in Japan, filenames are typically saved in Japanese with the standard English extension. Apply the same to any other language.
The only problem you will run into is that in an unsupported environment for that character set, people will usually just see a whole bunch of squares with an extension. Obviously this won't be a problem for your target users.
I have been playing around with Unicode and Indian languages for a while now. Here are my views on your questions:
Its easy. You will need two things: Enable Unicode (UTF-8/16/32) support in your OS so that you can type those characters and get Unicode compatible editors/tools so that your tools understand those characters.
Also, since you are looking at a localised web application, you have to ensure or atleast inform your visitor that he/she needs to have a browser which uses relevant encoding.
Your file extensions need not be i18-ned.
My two cents:
Key thing to international file names is to make URLs like bobince suggested:
www.example.com/files/%E3%81%93%E3%82%93%E3.txt
I had to make special routine for IE7 since it crop filename if its longer then 30 characters. So instead of "Your very long file name.txt" file will appear as "%d4y long file name.txt". However interesting thing is that IE7 actually understands header attachment;filename=%E3%81%93%E3%82%93%E3.txt correctly.