TarranJones
Reputation: 4242
PHP preg_replace find match in html but not if its a html attribute
I have two regex one which matches [value] and another which matches html attributes but i need to combine them into a single regex.
This is the regex I'm working with to find [value]
$tagregexp = '[a-zA-Z_\-][0-9a-zA-Z_\-\+]{2,}';
$pattern =
'\\[' // Opening bracket
. '(\\[?)' // 1: Optional second opening bracket for escaping shortcodes: [[tag]]
. "($tagregexp)" // 2: Shortcode name
. '(?![\\w-])' // Not followed by word character or hyphen
. '(' // 3: Unroll the loop: Inside the opening shortcode tag
. '[^\\]\\/]*' // Not a closing bracket or forward slash
. '(?:'
. '\\/(?!\\])' // A forward slash not followed by a closing bracket
. '[^\\]\\/]*' // Not a closing bracket or forward slash
. ')*?'
. ')'
. '(?:'
. '(\\/)' // 4: Self closing tag ...
. '\\]' // ... and closing bracket
. '|'
. '\\]' // Closing bracket
. '(?:'
. '(' // 5: Unroll the loop: Optionally, anything between the opening and closing shortcode tags
. '[^\\[]*+' // Not an opening bracket
. '(?:'
. '\\[(?!\\/\\2\\])' // An opening bracket not followed by the closing shortcode tag
. '[^\\[]*+' // Not an opening bracket
. ')*+'
. ')'
. '\\[\\/\\2\\]' // Closing shortcode tag
. ')?'
. ')'
. '(\\]?)'; // 6: Optional second closing bracket for escaping shortcodes: [[tag]]
This regex (\S+)=["']?((?:.(?!["']?\s+(?:\S+)=|[>"']))+.)["']? matches an attribute and a value.
example here
I would like the regex to match [value] in the following examples
<div [value] ></div><div>[value]</div>
but not find a match in this example
<input attr="attribute[value]"/>
Just need to make it into a single regex to use in my preg_replace_callback
preg_replace_callback($pattern, replace_matches, $html);
Upvotes: 0
Views: 319
Answers (1)
Ro Yo Mi
Reputation: 15000
Foreward
On the surface it looks like you're attempting to parse html code with a regular expression. I feel obligated to point out that it's not advisable to use a regex to parse HTML due to all the possible obscure edge cases that can crop up, but it seems that you have some control over the HTML so you should able to avoid many of the edge cases the regex police cry about.
Description
<\w+\s(?=(?:[^>=]|='[^']*'|="[^"]*"|=[^'"][^\s>]*)*?\[(?<DesiredValue>[^\]]*)\])
|
<\w+\s?(?:[^>=]|='[^']*'|="[^"]*"|=[^'"][^\s>]*)*>
(?:(?!<\/div>)(?!\[).)*\[(?<DesiredValue>[^\]]*)\]
This regular expression will do the following:
- capture the substring inside square brackets
[some value]- were
[value]is in the attributes of a tag - were
[value]is in not inside the attributes area of a tag - providing the substring is not nested inside another value
<input attrib=" [value] ">
- were
- the captured substring will not include the wrapping square brackets
- allow any tag name, or replace the
\wwith the desired tag names - allow
valueto be any string of characters - avoid difficult edge cases
Note: this regex is best used with the following flags:
- global
- dot matches new line
- ignore white space in expression
- allow duplicate named capture groups
Examples
Live Demo
https://regex101.com/r/tT0bN5/1
Sample Text
<div [value 1] ></div>
<div>[value 2]</div>
but not find a match in this example
<div attr="attribute[value 3]"/>
<img [value 4]>
<a href="http://[value 5]">[value 6]</a>
Sample Matches
MATCH 1
DesiredValue [6-13] `value 1`
MATCH 2
DesiredValue [29-36] `value 2`
MATCH 3
DesiredValue [121-128] `value 4`
MATCH 4
DesiredValue [159-166] `value 6`
Explanation
NODE EXPLANATION
----------------------------------------------------------------------
<div '<div'
----------------------------------------------------------------------
\s whitespace (\n, \r, \t, \f, and " ")
----------------------------------------------------------------------
(?= look ahead to see if there is:
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the least amount
possible)):
----------------------------------------------------------------------
[^>=] any character except: '>', '='
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
=' '=\''
----------------------------------------------------------------------
[^']* any character except: ''' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
' '\''
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
=" '="'
----------------------------------------------------------------------
[^"]* any character except: '"' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
" '"'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
= '='
----------------------------------------------------------------------
[^'"] any character except: ''', '"'
----------------------------------------------------------------------
[^\s>]* any character except: whitespace (\n,
\r, \t, \f, and " "), '>' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
)*? end of grouping
----------------------------------------------------------------------
\[ '['
----------------------------------------------------------------------
( group and capture to \1:
----------------------------------------------------------------------
[^\]]* any character except: '\]' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
) end of \1
----------------------------------------------------------------------
\] ']'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
<div '<div'
----------------------------------------------------------------------
\s? whitespace (\n, \r, \t, \f, and " ")
(optional (matching the most amount
possible))
----------------------------------------------------------------------
(?: group, but do not capture (0 or more times
(matching the most amount possible)):
----------------------------------------------------------------------
[^>=] any character except: '>', '='
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
=' '=\''
----------------------------------------------------------------------
[^']* any character except: ''' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
' '\''
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
=" '="'
----------------------------------------------------------------------
[^"]* any character except: '"' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
" '"'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
= '='
----------------------------------------------------------------------
[^'"] any character except: ''', '"'
----------------------------------------------------------------------
[^\s>]* any character except: whitespace (\n,
\r, \t, \f, and " "), '>' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
> '>'
----------------------------------------------------------------------
(?: group, but do not capture (0 or more times
(matching the most amount possible)):
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
< '<'
----------------------------------------------------------------------
\/ '/'
----------------------------------------------------------------------
div> 'div>'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
\[ '['
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
. any character
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
\[ '['
----------------------------------------------------------------------
( group and capture to \2:
----------------------------------------------------------------------
[^\]]* any character except: '\]' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
) end of \2
----------------------------------------------------------------------
\] ']'
Upvotes: 2