Valid URL separators - url

I have a long URL with several values.
Example 1:
http://www.domain.com/list?seach_type[]=0&search_period[]=1&search_min=3000&search_max=21000&search_area=6855%3B7470%3B7700%3B7730%3B7741%3B7742%3B7752%3B7755%3B7760%3B7770%3B7800%3B7840%3B7850%3B7860%3B7870%3B7884%3B7900%3B7950%3B7960%3B7970%3B7980%3B7990%3B8620%3B8643%3B8800%3B8830%3B8831%3B8832%3B8840%3B8850%3B8860%3B8881%3B9620%3B9631%3B9632
My variable search area contains only 4 number digits (example 4000, 5000), but can contain a lot of them. Right now I seperate these in the URL by using ; as separator symbol. Though as seen in Example 1, the ; is converted into %3B. This makes me believe that this is a bad symbol to use.
What is the best URL separator?

Moontear, I think you have misread the linked document. That limitation only applies to the "scheme" portion of the URL. In the case of WWW URLs, that is the "http".
The next section of the document goes on to say:
Thus, only alphanumerics, the special characters "$-_.+!*'(),", and
reserved characters used for their reserved purposes may be used
unencoded within a URL.
I'd personally use comma (,). However, plus (+) and dash (-) are both reasonable options as well.
BTW, that document also mentions that semi-colon (;) is reserved in some schemes.

Well, according to RFC1738, valid URLs may only contain the letters a-z, the plus sign (+), period and hyphen (-).
Generally I would go with a plus to separate your search areas. So your URL would become http://www.domain.com/list?seach_type=0&search_period=1&search_min=3000&search_max=21000&search_area=6855+7470+7700+...
--EDIT--
As GinoA pointed out I misread the document. Hence "$-_.+!*'()," are valid characters too. I'd still go with the + sign though.

If there are only numbers to separate, you have a large choice of separators. You can choose any letter for example.
Probably a space can be a good choice. It will be transformed into + character in the URL, so will be more readable than a letter.
Example: search_area=4000+5000+6000

I'm very late to the party, but a valid query string can repeat variables so instead of...
http://x.y.z/list?type=0&period=1&min=3000&max=21000&area=6855+7470+7700
...you could also use...
http://x.y.z/list?type=0&period=1&min=3000&max=21000&area=6855&area=7470&area=7700

"+" is to be interpreted as a space " " when the content-type is application/x-www-form-urlencoded (standard for HTML forms). This may be handled by your server software.
I prefer "!". It doesn't get URL encoded (at least not in Chrome) and it reserves "+" for use as a real space character in the typical case.

Related

How is it possible to include a space in a URL

When using Chatstep, I noticed when typing a room name, it automatically updates in the URL bar, plus spaces are allowed! You can even share the link with a space, and the recepient can join seamlessly. Here is an example of what I'm talking about: "https://chatstep.com/#this is a space test" (just copy and paste inside the quotations, SE is messing up the clickable link)
As I thought spaces in links were impossible, how is this possible?
URLs always need to be encoded if they contain any kind of special characters, including space. That is usually done with percent encoding, but for space characters the special encoding to a plus sign '+' can be used.
(A literal '+' itself is a reserved character before encoding and would need to be encoded to '%2B'.)
However, modern browsers show some intelligence when dealing with URLs and can apply that encoding transparently when necessary. If you're on Firefox, try using Live HTTP Headers or Firebug to see the request actually sent to the server when you click that link.
Another way would be to enforce the percent character in the URL. If %20 equals "Space" and %25 equals "%", then replacing spaces by %2520 will write %20 in your URL, keeping it unified (rather than separated by spaces).
Example: https://chatstep.com/#this%2520is%2520a%2520space%2520test
Result: https://chatstep.com/#this%20is%20a%20space%20test

Is there a character that is illegal in all parts of a URI?

I need a character to separate two or more URIs in one string. Later I will the split the string to get each URI separately.
The problem is I'm not sure what character to pick here. Is there a good character to choose here that definitely can't be part of a URI itself? Or is ultimately pretty much all characters allowed in a URI?
I know certain characters are illegal in certain parts of the URI, but I'm talking about a URI as a whole, like this:
scheme://username:password#domain.tld/path/to/file.ext?key=value#blah
I'm thinking maybe space, although technically I suppose that could be part of the password, or would it be escaped as %20 in that case?
Any of the control characters should be good for this, such as TAB, FF and so on.
RFC3986 (a) controls the URI specification and Appendix A of that RFC states that the characters are limited to:
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
0123456789-._~:/?#[]#!$&'()*+,;=
(and the % encoding character, of course, for all other characters not listed above).
So, basically, any other character should be okay as a delimiter.
(a) This has actually been augmented by RFC6874 which has to do with changes to the IPv6 part of the URI, adding a zone identifier. Since the zone ID consists of % and "unreserved" characters already included above, it doesn't change the set of characters allowed.

Using commas in URL's can break the URL sometimes?

Is anyone aware of any problems with using commas in SEO friendly URL's? I'm working with some software that uses a lot of commas in it's SEO friendly URL's; but I am 100% certain I have seen some instances where some programs/platforms don't recognize the URL correctly & cut the "linking" of the URL off after the first comma.
I just tested this out with thunderbird, gmail, hotmail & on a SMF forum with no problems; however I know I have seen the issue before.
So my question is, is there anything in particular that would cause some platforms to stop linking URL's with a comma? Such as a certain character after the comma?
There will be countless implementations that will cut the automatical linking at that point. As with many other characters, too. But that’s not a problem because of using these characters, but because of a wrong/incomplete implementation.
See for example this very site, Stack Overflow. It will cut off the link at the * when manually entering/pasting this URL (see bug; in case it gets fixed, here’s a screenshot of it):
http://wayback.archive.org/web/*/http://www.example.com/
But when using the hyperlink syntax, it works fine:
http://wayback.archive.org/web/*/http://www.example.com/
The * character is allowed in an HTTP URL path, so the link detection should have recognized the first URL instead of breaking it at the occurence of *.
Regarding the comma:
The comma is a reserved character and its meaning is relevant for the URL path (bold emphasis mine):
Aside from dot-segments in hierarchical paths, a path segment is
considered opaque by the generic syntax. URI producing applications
often use the reserved characters allowed in a segment to delimit
scheme-specific or dereference-handler-specific subcomponents. For
example, the semicolon (";") and equals ("=") reserved characters are
often used to delimit parameters and parameter values applicable to
that segment. The comma (",") reserved character is often used for
similar purposes. For example, one URI producer might use a segment
such as "name;v=1.1" to indicate a reference to version 1.1 of
"name", whereas another might use a segment such as "name,1.1" to
indicate the same.
So, if you don’t intend to use the comma for the function it has as reserved character, you may want to percent-encode it with %2C. Users copying such an URL from their browser’s address bar would paste it in the encoded form, so it should work almost everywhere.
However, especially because it’s a reserved character, the unencoded form should work, too.

why use - instead off _ in url

why use - instead off _ in url?
Url contain '_' seems like no bad effects.
Underscores are not allowed in a host name. Thus some_place.com is not a valid URL because the host name is not valid. Underscores are permissible in URLS. Thus some-place.com/which_place/ is perfectly legitimate, other concerns aside.
From RFC 1738:
host
[...] Fully qualified domain names take the form as described
in Section 3.5 of RFC 1034 [13] and Section 2.1 of RFC 1123
[5]: a sequence of domain labels separated by ".", each domain
label starting and ending with an alphanumerical character and
possibly also containing "-" characters. The rightmost domain
label will never start with a digit, though, which
syntactically distinguishes all domain names from the IP
addresses.
When you read a_long_sentence_with_many_underscores, because you are reading it by letter or word recognition, your eye tracks along the middle of the line, but when you reach an underscore, your eye is more likely to track down a bit and back up for the next word.
When you read a-long-sentence-with-many-dashes, your eye keeps tracking along the same horizon, and by sight, it is easier for your brain to try and ignore them.
Another good reason is that Google and other search engines rank urls that match to search terms higher when the word separator is a dash.
One main reason is that most anchor tags have text-decoration:underline which effectively hides your underscore.
And, a non-tech savvy user wont automatically assume that there is an underscore :)
By the way... it seems several Java network libraries will not be able to interpret a URL correctly when using underscore:
URI uri = URI.create("http://www.google-plus.com/");
System.out.println(uri.getHost()); // prints www.google-plus.com
URI uri = URI.create("http://www.google_plus.com/");
System.out.println(uri.getHost()); // prints null
It's easier to type (at least on my german keyboard) and see.

Why do you need to encode URLs?

Why do you need to encode urls? Is there a good reason why you have to change every space in the GET data to %20?
Because some characters have special meanings.
For instance, in a query string, the ampersand (&) is used as a separator between key-value pairs. If you were to put an ampersand into one of those values, it would look like the separator between the end of a value and the beginning of the next key. So for special characters like this, we use percent encoding so that we can be sure that the data is unambiguously encoded.
From RFC 2936, section 2.4.3:
The space character is excluded
because significant spaces may
disappear and insignificant spaces may
be introduced when URI are transcribed
or typeset or subjected to the
treatment of word- processing
programs. Whitespace is also used to
delimit URI in many contexts.
originally older browsers could get confused by the spaces (not really an issue anymore).
now, if someone copies the url to send as a link - the space can break the hyperlink - ie
Hey! Check out this derping cat playing a piano!
http://www.mysite.com/?video=funny cat plays piano.
See how the link breaks?
Now look at this:
http://www.mysite.com/?video=funny%20cat%20plays%20piano.
Let's break down your question.
Why do you need to encode URL?
A URL is composed of only a limited number of characters and those are digits(0-9), letters(A-Z, a-z), and a few special characters("-", ".", "_", "~").
So does it mean that we cannot use any other character?
The answer to this question is "YES". But wait a minute, there is a hack and the hack is URL Encoding or Perchantage Encoding. So if you want to transmit any character which is not a member of the above mentioned (digits, letters, and special chars), then we need to encode them. And that is why we need to encode "space" as "%20".
OK? Is this enough for URL encoding? No this is not enough, there's a lot about URL encoding but here, I'm not gonna make it a pretty big, boring technical answer. But If you want to know more, then you can read it from here: https://www.urlencoder.io/learn/ (Credit goes to this writer)
Well, you do so because every different browsers knows how the string that makes up the URL is encoded. converting the space to %20, etc makes that URL/URI portable. It could be latin-1 it could be unicode. It needs normalized to something that is understood universally. Take a look at rfc3986 https://www.rfc-editor.org/rfc/rfc3986#section-2.1

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