More fun with [E], escaping quotes

[csdude55]

Shout out to @w3dk for telling me this one:

Instead of backslash escaping spaces, you can surround the entire flags argument with double quotes:

"[E=example:Lorem ipsum dolor sit amet consectetur]"

Now I'm expanding upon that...

I'm setting a variable that's a string like this:

<H3 data-logo onClick="location.href='%{ENV:home}';">${lc:$1}</H3>

It's actually a bit longer than that, but I'm cutting out a chunk of it for this post. I originally had it as a switch-case in PHP, but processing it this way seems to be notably faster. Note that the string has both double-quotes and single-quotes, though.

So at first I did it like this:

RewriteRule ^ - [E=foo:<H3\ data-logo\ onClick="location.href=\ '%{ENV:home}';">${lc:$1}</H3>]

and now, based on @w3dk 's explanation, I'm trying to do it like this:

RewriteRule ^ - '[E=foo:<H3 data-logo onClick="location.href='%{ENV:home}';">${lc:$1}</H3>]'

In testing, though, I discovered that these all throw an error of RewriteRule: bad flag delimiters:

# Using \ to escape the nested '
RewriteRule ^ - '[E=foo:<H3 data-logo onClick="location.href= \'%{ENV:home}\';">${lc:$1}</H3>]'

# Double-escaping
RewriteRule ^ - '[E=foo:<H3 data-logo onClick="location.href= \\'%{ENV:home}\\';">${lc:$1}</H3>]'

# Triple-escaping
RewriteRule ^ - '[E=foo:<H3 data-logo onClick="location.href= \\\'%{ENV:home}\\\';">${lc:$1}</H3>]'

# Using a double quote to wrap, then escaping the doubles instead
RewriteRule ^ - "[E=foo:<H3 data-logo onClick=\"location.href= '%{ENV:home}';\">${lc:$1}</H3>]"

# Using a tilde to wrap instead of '
RewriteRule ^ - `[E=foo:<H3 data-logo onClick="location.href= '%{ENV:home}';">${lc:$1}</H3>]`

I know that I could encode it with something like %squot; (or anything, really) and then use str_replace in PHP to swap it back to a single quote, but that would kinda defeat the purpose. So before I give up and go back to escaping the whitespaces with no wrapping quotes, is there some other way of escaping the nested quotes that I'm overlooking?

[w3dk]

It looks like you are going beyond what "simple environment variables" are meant to be used for.

If you have an environment variable value that should contain all three... spaces, single-quotes and double-quotes, then it does look like you would need to revert to backslash escaping the literal spaces. The single and double-quotes can then be used as-is in the env var value.

However, you can also build up the final value using multiple directives to avoid complex escaping. For example:

RewriteRule ^ - [E=foo:"location.href='%{ENV:home}';"]
RewriteRule ^ - "[E=foo:<H3 data-logo onClick=%{ENV:foo}>${lc:$1}</H3>]"

(The space after "location.href=" is not required, so this simplifies the first assignment.)

I'm setting a variable that's a string like this:

<H3 data-logo onClick="location.href='%{ENV:home}';">${lc:$1}</H3>

I assume you are expecting "%{ENV:home}" and "${lc:$1}" to be evaluated before the value is assigned to the env var (ie. you don't want to store this literal text in the env var?!), but what is "$1" supposed to refer to in this example? (In the examples you posted, the $1 backreference is always empty.)

[csdude55]

It looks like you are going beyond what "simple environment variables" are meant to be used for.

Yes and no. What I have is 55 domains parked on top of a main domain, and I used to use PHP to read the domain name and then set variables based on that domain. If the user was at the default domain then I would use the second level of the URL; eg, example.com/no_domain

What I found, though, was that I was shaving a good amount of time off of every pageview by moving it to Apache. So it's not REALLY that complex, just lengthy.

I assume you are expecting "%{ENV:home}" and "${lc:$1}" to be evaluated before the value is assigned to the env var (ie. you don't want to store this literal text in the env var?!), but what is "$1" supposed to refer to in this example? (In the examples you posted, the $1 backreference is always empty.)

Oops, sorry about that! I was trying to make things easier to read for you, and just made it harder :-/

The actual code looks like this:

# %{ENV:domain} is determined earlier
RewriteCond %{ENV:domain} ^example?$

# I also let the user define the domain with example.com?default=whatever
RewriteCond %{QUERY_STRING} !(?:^|&)default=[a-z]+ [NC]

# define all of the allowed first-level pages
# if it's not one of these then the first level must be one of the pre-defined possibilities
RewriteCond %{REQUEST_URI} !^/(?:lorem|ipsum|53_others)[/$] [NC]

# $1 is the first level of the URL
# %{ENV:home} is defined earlier, too
# I actually set 4 variables here, so this is abbreviated to the relevant part
RewriteRule ^/([a-z]+) - [E=foo:<H3\ data-logo\ onClick="location.href='%{ENV:home}';">${lc:$1}</H3>]

However, you can also build up the final value using multiple directives to avoid complex escaping.

That's pretty slick :-) I wouldn't need the "location.href=whatever" unless these 3 conditions match, but there's no reason that I couldn't create it ahead of time and just not use it if they don't match. Eg,

RewriteRule ^ - [E=bar:"location.href='%{ENV:home}';"]

RewriteCond %{ENV:domain} ^example?$
RewriteCond %{QUERY_STRING} !(?:^|&)default=[a-z]+ [NC]
RewriteCond %{REQUEST_URI} !^/(?:lorem|ipsum|53_others)[/$] [NC]
RewriteRule ^/([a-z]+) - "[E=foo:<H3 data-logo onClick=%{ENV:bar}>${lc:$1}</H3>]"