Redirector Help

Table of contents

1. What is Redirector?
2. Basic usage
   • Example url
   • Include pattern
   • Exclude pattern
   • Redirect to
   • Pattern type
   • Only if link exists
3. Wildcards
4. Regular expressions
5. XPath redirects
6. Examples

What is Redirector?

Redirector is an extension for Firefox that allows you to automatically redirect from one webpage to another. For example, every time you visit http://abc.com you will automatically load http://def.com instead. This can be useful for instance to always redirect articles to printer friendly versions, redirect http:// to https:// for sites that support both, bypass advertising pages that appear before being able to view certain pages and more.

Basic usage

To add a new redirect you can go to the Tools menuitem and select Redirector. That will open the Redirector settings window which shows all your redirects. The window can also be opened by right clicking on the R icon in your statusbar and selecting Manage redirects. There you can press the Add... button and then you can enter the details for the new redirect. A redirect consists of a few things:

• Example url: This is an example of an url you want to redirect. It is not really used for anything, it's just there to show what types of urls you're targetting. You can leave this out, but then you can't use the Test pattern button.
• Include pattern: This is pattern for the urls you want to redirect. In the simplest case, where you just want to redirect one specific url to another then this will just be the exact url you want to redirect. For instance, if you just want http://aaa.com to redirect to http://bbb.com then Include pattern will just be http://aaa.com. For more complex patterns that match many urls you can use either wildcards or regular expressions.
• Exclude pattern: Urls that match this pattern will never be redirected. This is not necessary to fill out, but can be useful when you want to redirect all urls that contain some text except if they contain some other text. Redirects like that can often be done with a complex regular expression, but using an exclude pattern makes it much simpler. The exclude patterns can use wildcard characters or regular expressions like the include patterns.
• Redirect to: This is the url that you will be redirected to when you open any page where the url matches the include pattern. You can use the special signs $1, $2, $3 etc. in the url, they will be replaced by the results of captures with regular expressions or stars with wildcards. For instance, if you have the include pattern http://google.com/*, redirect to http://froogle.com/$1 and you open the page http://google.com/foobar, then you will be redireced to http://froogle.com/foobar, since 'foobar' was what the star replaced. $1 is for the first star in the pattern, $2 for the second and so on. For regular expression $1 is for the first parantheses, $2 for the second etc. The redirect url can also be specified as a XPath expression.
• Pattern type: This specifies how Redirector should interpret the patterns, either as wildcards or regular expressions.
• Only if link exists: If this is checked then the redirect will only happen if there is a link to the target page on the page that matches the include pattern. For instance, if you have a redirect from http://foo.com to http://bar.com and check Only if link exists then http://foo.com has to have a hyperlink to http://bar.com, otherwise nothing will happen.

Wildcards

Wildcards are the simplest way to specify include and exclude patterns. When you create a wildcard pattern there is just one special character, the asterisk *. An asterisk in your pattern will match zero or more characters and you can have more than one star in your pattern. Some examples:

• http://example.com/* matches http://example.com/, http://example.com/foo, http://example.com/bar and all other urls that start with http://example.com/.
• http://*.example.com matches all subdomains of example.com, like http://www.example.com, http://mail.example.com.
• http*://example.com matches both http://example.com and https://example.com.
• http://example.com/index.asp* matches http://example.com/index.asp, http://example.com/index.asp?a=b&c=d.

• http://example.com/* matches http://example.com/foobar, $1 is foobar.
• http://*.example.com/* matches http://www.example.com/foobar, $1 is www, $2 is foobar.

Regular expressions

Regular expressions allow for more complicated patterns but they are a lot harder to learn than wildcards. I'm not gonna create a regex tutorial here but normal javascript regex syntax works, look at http://regular-expressions.info for an introduction to regular expressions. $1,$2 etc. can be used in the redirect url and will be replaced with contents of captures in the regular expressions. Captures are specified with parantheses. Example: http://example.com/index.asp\?id=(\d+) will match the url http://example.com/index.asp?id=12345 and $1 will be replaced by 12345. (A common mistake in regex patterns is to forget to escape the ? sign in the querystring of the url. ? is a special character in regular expressions so if you want to match an url with a querystring you should escape it as \?).

XPath redirects

The redirect url can be specified as an xpath expression by starting it with xpath: and then you will be redirected to the url that the xpath expression matches. Example: Redirect url is xpath:/div/span/a/@href, then you will be redirected to the href value of the first link that's inside a div in the original page.

Examples

To be continued in next version...