How to attach same RewriteCond to different RewriteRule in .htaccess? – Apache

/news/detail.html?id=1 -> /api/v1/informations/ogp/1?lang=ja
/news/detail.html?id=1&lang=en -> /api/v1/informations/ogp/1?lang=en

/sport/detail.html?id=1 -> /api/v1/sports/ogp/1?lang=ja
/sport/detail.html?id=1&lang=en -> /api/v1/sports/ogp/1?lang=en

/event/common/detail.html?id=1 -> /api/v1/events/ogp/1?lang=ja
/event/common/detail.html?id=1&lang=en -> /api/v1/events/ogp/1?lang=en

/event/special/detail.html?id=2 -> /api/v1/events/ogp/2?lang=ja
/event/special/detail.html?id=2&lang=en -> /api/v1/events/ogp/2?lang=en

This is really only 4 URL mappings (when the lang param is omitted it assigned a default – the target remains the same), so you only need 4 rules (if you extract the lang param). And the last 2 redirect to the same target so these can be easily combined (using regex alternation (common|special)), leaving just 3 separate rules that are required.

You could do it like this to avoid any repetition:

RewriteEngine On
RewriteBase /api/v1

# Get "lang" (default to "ja")
RewriteRule ^ - [E=LANG:ja]
RewriteCond %{QUERY_STRING} (?:^|&)lang=(w+)($|&)
RewriteRule ^ - [E=LANG:%1]

# Get "id" (if any)
RewriteCond %{QUERY_STRING} (?:^|&)id=(d+)($|&)
RewriteRule ^ - [E=ID:%1]

# If not Facebook|Twitter OR no ID then skip the next 3 rules
RewriteCond %{HTTP_USER_AGENT} !^(facebook(externalhit|platform)|twitterbot) [NC,OR]
RewriteCond %{ENV:ID} ^$
RewriteRule ^ - [S=3]

# If here then Facebook|Twitter and "id" param are passed, LANG already set
RewriteRule ^news/detail.html$ informations/ogp/%{ENV:ID}?lang=%{ENV:LANG} [R,L]
RewriteRule ^sport/detail.html$ sports/ogp/%{ENV:ID}?lang=%{ENV:LANG} [R,L]
RewriteRule ^event/(common|special)/detail.html$ events/ogp/%{ENV:ID}?lang=%{ENV:LANG} [R,L]

The trick here is the use of the S (skip) flag to skip over the following 3 rules when the User-Agent is not Facebook or Twitter (or there is no id URL param present) – reversing the logic. Which means that the last 3 rules are only processed when the User-Agent is Facebook or Twitter and the id URL param is present.

Note that I used non-capturing subpatterns to ensure that the backreferences (ie. %1) only refer to the group we are interested in.

NB: I changed the RewriteBase to "simplify" the last 3 rules. Although if you have other directives then you may want to change this back.

I tried the method of using the If directive, but it didn’t work

Your current rules would have failed to match inside an <If> directive (Apache 2.4), because in this context the RewriteRule directive matches against the absolute file-path, not a relative URL-path (probably because <If> containers are merged very late).

Providing there are no conflicts, a simple workaround here is to just remove the start-of-string anchor (^) from the start of the RewriteRule pattern so as to be able to match a file-path of the form /absolute/file/path/to/public_html/news/detail.php. (Although I would probably add a slash prefix in order to avoid any partial path-segment matches.)

So, you could potentially write it like this instead using an <If> expression:

RewriteEngine On

# Get "id" (if any)
RewriteCond %{QUERY_STRING} (?:^|&)id=(d+)($|&)
RewriteRule ^ - [E=ID:%1]

# Facebook|Twitter AND "id" param are passed
<If "%{HTTP_USER_AGENT} =~ /^(?i)(facebook(externalhit|platform)|twitterbot)/ && reqenv('ID') =~ /d+/">
    # Get "lang" (default to "ja")
    RewriteRule ^ - [E=LANG:ja]
    RewriteCond %{QUERY_STRING} (?:^|&)lang=(w+)($|&)
    RewriteRule ^ - [E=LANG:%1]

    # Redirects
    RewriteRule /news/detail.html$ /api/v1/informations/ogp/%{ENV:ID}?lang=%{ENV:LANG} [R,L]
    RewriteRule /sport/detail.html$ /api/v1/sports/ogp/%{ENV:ID}?lang=%{ENV:LANG} [R,L]
    RewriteRule /event/(common|special)/detail.html$ /api/v1/events/ogp/%{ENV:ID}?lang=%{ENV:LANG} [R,L]
</If>