问题
I'm in the process of migrating content from phpBB to WordPress. I have suceeded up to the point of translating the bbcode into html.
The BBCode is complicated by an alphanumeric string that is injected into each tag.
A common post will contain text like so...
[url=url] Click here [/url:583ow9wo]
[b:583ow9wo] BOLD [/b:583ow9wo]
[img:583ow9wo] jpg [/img:583ow9wo]
I am inexperienced with Regular Expressions but believe this may be a way out, as I found some help from the following post https://stackoverflow.com/a/5505874/4356865 (use regex [/?b:\d{5}] ) but the regex in this instance will only remove the numeric characters from this example.
Any help appreciated.
回答1:
Something like this will work for tags that have no attributes:
\[(b|i|u)(:[a-z0-9]+)?\](.*?)\[\/\1(?:\2)?\]
\[ -- matches literal "["
(b|i|u) -- matches b, i, or u, captures as backreference 1
(:[a-z0-9]+)? -- matches colon and then alphanumeric string, captures as backreference 2
-- the question mark allows the :string not to be present.
\] -- matches literal "]"
(.*?) -- matches anything*, as few times as required to finish the match, creates backreference 3.
\[ -- matches literal "["
\/ -- matches literal "/"
\1 -- invokes backreference 1 to make sure the opening/closing tags match
(?:\2)? -- invokes backreference 2 to further make sure it's the same tag
\] -- matches literal "]"
Matching a tag like url is easy enough
With tags that have attributes, they do different things with their attributes, and so it's probably easier to handle a tag like URL seperately from a tag like IMG.
\[(url)(?:\s*=\s*(.*?))?(:[a-z0-9]+)\](.*?)\[\/\1(?:\3)?\]
\[ -- matches literal "["
(url) -- matches literal "url", in parentheses so we can invoke backreference 1 later, easier for you to modify
(?: -- ?: signifies a non-capturing group, so it creates a group without creating a backreference, or altering the backreference count.
\s*=\s* -- matches literal "=", padded by any amount of whitespace on either side
(.*?) -- matches any character, as few times as possible, to complete the match, creates backreference 2
) -- closes the noncapturing group
(:[a-z0-9]+) -- matches the alphanumeric string as backreference 3.
\] -- matches literal "]"
(.*?) -- matches any character as few times as possible to complete the match, backreference 4
\[ -- matches literal "["
\/ -- matches literal "/"
\1 -- invokes backreference 1
(?:\3)? -- invokes backreference 3
\] -- matches literal "["
For your replacing, the contents of the tags are in backreferences themselves so you can do something like this for the b/i/u tags.
<\1>\3</\1>
For the url tag, it's something like this
<A href="\2">\4</A>
I say that the dot/period matches any character in multiple places. It matches any character except newline. You can turn the newline modifier in your regex on by using the "dotall"
modifier s
like this
/(.*)<foo>/s
来源:https://stackoverflow.com/questions/27459103/phpbb-bbcode-to-html-regex-or-otherwise