I would like to parse shortcode into array via "preg_split".
This is example shortcode:
[contactform id="8411" label="This is \" first label" label2='This is second \' label']
and this should be result array:
Array
(
[id] => 8411
[label] => This is \" first label
[label2] => This is second \' label
)
I have this regexp:
$atts_arr = preg_split('~\s+(?=(?:[^\'"]*[\'"][^\'"]*[\'"])*[^\'"]*$)~', trim($shortcode, '[]'));
Unfortunately, this works only if there is no escaping of quotes \' or \".
Thx in advance!
Using preg_split is not always handy or appropriate in particular when you have to deal with escaped quotes. So, a better approach consists to use preg_match_all, example:
$pattern = <<<'EOD'
~
(\w+) \s*=
(?|
\s* "([^"\\]*(?:\\.[^"\\]*)*)"
|
\s* '([^'\\]*(?:\\.[^'\\]*)*)'
# | uncomment if you want to handle unquoted attributes
# ([^]\s]*)
)
~xs
EOD;
if (preg_match_all($pattern, $yourshortcode, $matches))
$attributes = array_combine($matches[1], $matches[2]);
The pattern uses the branch reset feature (?|...(..)...|...(...)..) that gives the same number(s) to the capture groups for each branch.
I was speaking about the \G anchor in my comment, this anchor succeeds if the current position is immediatly after the last match. It can be useful if you want to check the syntax of your shortcode from start to end at the same time (otherwise it is totally useless). Example:
$pattern2 = <<<'EOD'
~
(?:
\G(?!\A) # anchor for the position after the last match
# it ensures that all matches are contiguous
|
\[(?<tagName>\w+) # begining of the shortcode
)
\s+
(?<key>\w+) \s*=
(?|
\s* "(?<value>[^"\\]*(?:\\.[^"\\]*)*)"
|
\s* '([^'\\]*(?:\\.[^'\\]*)*')
# | uncomment if you want to handle unquoted attributes
# ([^]\s]*)
)
(?<end>\s*+]\z)? # check that the end has been reached
~xs
EOD;
if (preg_match_all($pattern2, $yourshortcode, $matches) && isset($matches['end']))
$attributes = array_combine($matches['key'], $matches['value']);
Related
Well, hello community. I'm workin' on a CSV decoder in PHP (yeah, I know there's already one, but as a challenge for me, since I'm learning it in my free time). Now the problem: Well, the rows are split up by PHP_EOL.
In this line:
foreach(explode($sep, $str) as $line) {
where sep is the variable which splits up the rows and str the string I wanna decode.
But if I wanna split up the columns by a semicolon there might be a situation where a semicolon is content of one column. And as I researched this problem is solved by surrounding the whole column by quote signs like this:
Input:
"0;0";1;2;3;4
Expected output:
0;0 | 1 | 2 | 3 | 4
I already thought of lookahead/lookbehind. But as I didn't use it in past and maybe this could be a good practice for it I don't know how to include it in the regex. My decoding function returns a 2D-array (like a table...) and I thought of adding rows to the array like this (Yep, the regex is f***ed up...):
$res[] = preg_split("/(?<!\")". preg_quote($delim). "(?!\")/", $line);
And at last my full code:
function csv_decode($str, $delim = ";", $sep = PHP_EOL) {
if($delim == "\"") $delim = ";";
$res = [];
foreach(explode($sep, $str) as $line) {
$res[] = preg_split("/(?<!\")". preg_quote($delim). "(?!\")/", $line);
}
return $res;
}
Thanks in advance!
It's a bit counter-intuitive, but the simplest way to split a string by regex is often to use preg_match_all in place of preg_split:
preg_match_all('~("[^"]*"|[^;"]*)(?:;|$)~A', $line, $m);
$res[] = $m[1];
The A modifier ensures the contiguity of the successive matches from the start of the string.
If you don't want the quotes to be included in the result, you can use the branch reset feature (?|..(..)..|..(..)..):
preg_match_all('~(?|"([^"]*)"|([^;"]*))(?:;|$)~A', $line, $m);
Other workaround, but this time for preg_split: include the part you want to avoid before the delimiter and discard it from the whole match using the \K feature:
$res[] = preg_split('~(?:"[^"]*")?\K;~', $line);
You can use this function str_getcsv in this you can specify a custom delimiter(;) as well.
Try this code snippet
<?php
$string='"0;0";1;2;3;4';
print_r(str_getcsv($string,";"));
Output:
Array
(
[0] => 0;0
[1] => 1
[2] => 2
[3] => 3
[4] => 4
)
Split is not a good choice for csv type lines.
You could use the old tried and true \G anchor with a find globally type func.
Practical
Regex: '~\G(?:(?:^|;)\s*)(?|"([^"]*)"|([^;]*?))(?:\s*(?:(?=;)|$))~'
Info:
\G # G anchor, start where last match left off
(?: # leading BOL or ;
(?: ^ | ; )
\s* # optional whitespaces
)
(?| # branch reset
"
( [^"]* ) # (1), double quoted string data
"
| # or
( [^;]*? ) # (1), non-quoted field
)
(?: # trailing optional whitespaces
\s*
(?:
(?= ; ) # lookahead for ;
| $ # or EOL
)
)
I have a string describing a [ variable operator value ] structure like this:
type == 'prova' && padposition == "stefano" or 10>var_name
I need to build a regular expression to extract the variable name list:
type
padposition
var_name
to apply a post processing on them (basically converting them into key of a PHP array):
$arr_name['type']
$arr_name['padposition']
$arr_name['var_name']
I've found the way to match string delimited by single or double quotes:
('|")(\w*\w)('|")
but I'm not able (I'm too ignorant!) to negate it or simply to extract any word non single or double quote delimited.
A way to do it (highly readable and easy to maintain):
$str = 'type == \'prova\' && padposition == "stefano" or 10>var_name';
$pattern = <<<'EOD'
~
# you define first the basic elements (as for a lexer) with named groups
(?(DEFINE)
(?<var> [a-z_]\w* ) # variable name
(?<dqstr> (?<=") [^\\"]*+ (?s:\\.[^\\"]*)*+ (?=") ) # double quoted string
(?<sqstr> (?<=') [^\\']*+ (?s:\\.[^\\']*)*+ (?=') ) # single quoted string
(?<string> \g<dqstr> | \g<sqstr> ) # any string
(?<num> [0-9]+(?:\.[0-9]+)? ) # a number
(?<value> \g<string> | \g<num> ) # any value
(?<comp> [!><=]= | =?[><] ) # comparison operator
)
# Then you write the pattern using these named groups
(?J) # allow duplicate named groups
# variable op value
(?<key> \g<var> ) \h* \g<comp> \h* ["']? (?<val> \g<value> ) ['"]?
| # OR
# value op variable
["']? (?<val> \g<value> ) ['"]? \h* \g<comp> \h* (?<key> \g<var> )
~xi
EOD;
if (preg_match_all($pattern, $str, $matches, PREG_SET_ORDER)) {
$arr_name = [];
foreach($matches as $m) {
$arr_name[$m['key']] = $m['val'];
}
print_r($arr_name);
}
Pattern demo
I've found several partial answers to this question, but none that cover all my needs...
I am trying to parse a user generated string as if it were a series of php function arguments to determine the number of arguments:
This string:
$arg1,$arg2='ABC,DEF',$arg3="GHI\",JKL",$arg4=array(1,'2)',"3\"),")
will be inserted as the arguments of a function:
function my_function( [insert string here] ){ ... }
I need to parse the string on the commas, taking into account single- and double-quotes, parentheses, and escaped quotes and parentheses to create an array:
array(4) {
[0] => $arg1
[1] => $arg2='ABC,DEF'
[2] => $arg3="GHI\",JKL"
[3] => $arg4=array(1,'2)',"3\"),")
}
Any help with a regular expression or parser function to accomplish this is appreciated!
It isn't possible to solve this problem with a classical csv tool since there is more than one character able to protect parts of the string.
Using preg_split is possible but will result in a very complicated and inefficient pattern. So the best way is to use preg_match_all. There are however several problems to solve:
as needed, a comma enclosed in quotes or parenthesis must be ignored (seen as a character without special meaning, not as a delimiter)
you need to extract the params, but you need to check if the string has the good format too, otherwise the match results may be totally false!
For the first point, you can define subpatterns to describe each cases: the quoted parts, the parts enclosed between parenthesis, and a more general subpattern able to match a complete param and that uses the two previous subpatterns when needed.
Note that the parenthesis subpattern needs to refer to the general subpattern too, since it can contain anything (and commas too).
The second point can be solved using the \G anchor that ensures that all matchs are contiguous. But you need to be sure that the end of the string has been reached. To do that, you can add an optional empty capture group at the end of the main pattern that is created only if the anchor for the end of the string \z succeeds.
$subject = <<<'EOD'
$arg1,$arg2='ABC,DEF',$arg3="GHI\",JKL",$arg4=array(1,'2)',"3\"),")
EOD;
$pattern = <<<'EOD'
~
# named groups definitions
(?(DEFINE) # this definition group allows to define the subpatterns you want
# without matching anything
(?<quotes>
' [^'\\]*+ (?s:\\.[^'\\]*)*+ ' | " [^"\\]*+ (?s:\\.[^"\\]*)*+ "
)
(?<brackets> \( \g<content> (?: ,+ \g<content> )*+ \) )
(?<content> [^,'"()]*+ # ' # (<-- comment for SO syntax highlighting)
(?:
(?: \g<brackets> | \g<quotes> )
[^,'"()]* # ' #
)*+
)
)
# the main pattern
(?: # two possible beginings
\G(?!\A) , # a comma contiguous to a previous match
| # OR
\A # the start of the string
)
(?<param> \g<content> )
(?: \z (?<check>) )? # create an item "check" when the end is reached
~x
EOD;
$result = false;
if ( preg_match_all($pattern, $subject, $matches, PREG_SET_ORDER) &&
isset(end($matches)['check']) )
$result = array_map(function ($i) { return $i['param']; }, $matches);
else
echo 'bad format' . PHP_EOL;
var_dump($result);
demo
You could split the argument string at ,$ and then append $ back the array values:
$args_array = explode(',$', $arg_str);
foreach($args_array as $key => $arg_raw) {
$args_array[$key] = '$'.ltrim($arg_raw, '$');
}
print_r($args_array);
Output:
(
[0] => $arg1
[1] => $arg2='ABC,DEF'
[2] => $arg3="GHI\",JKL"
[3] => $arg4=array(1,'2)',"3\"),")
)
If you want to use a regex, you can use something like this:
(.+?)(?:,(?=\$)|$)
Working demo
Php code:
$re = '/(.+?)(?:,(?=\$)|$)/';
$str = "\$arg1,\$arg2='ABC,DEF',\$arg3=\"GHI\",JKL\",\$arg4=array(1,'2)',\"3\"),\")\n";
preg_match_all($re, $str, $matches);
Match information:
MATCH 1
1. [0-5] `$arg1`
MATCH 2
1. [6-21] `$arg2='ABC,DEF'`
MATCH 3
1. [22-39] `$arg3="GHI\",JKL"`
MATCH 4
1. [40-67] `$arg4=array(1,'2)',"3\"),")`
I'm unsure if I should be using preg_match, preg_match_all, or preg_split with delim capture. I'm also unsure of the correct regex.
Given the following:
$string = " ok 'that\\'s cool' \"yeah that's \\\"cool\\\"\"";
I want to get an array with the following elems:
[0] = "ok"
[1] = "that\'s"
[2] = "yeah that's \"cool\""
You can not do this with a regular expression because you're trying to parse a non-context-free grammar. Write a parser.
Outline:
read character by character, if you see a \ remember it.
if you see a " or ' check if the previous character was \. You now have your delimiting condition.
record all the tokens in this manner
Your desired result set seems to trim spaces, you also lost a couple of the \s, perhaps this is a mistake but it can be important.
I would expect:
[0] = " ok " // <-- spaces here
[1] = "that\\'s cool"
[2] = " \"yeah that's \\\"cool\\\"\"" // leading space here, and \" remains
Actually, you might be surprised to find that you can do this in regex:
preg_match_all("((?|\"((?:\\\\.|[^\"])+)\"|'((?:\\\\.|[^'])+)'|(\w+)))",$string,$m);
The desired result array will be in $m[1].
You can do it with a regex:
$pattern = <<<'LOD'
~
(?J)
# Definitions #
(?(DEFINE)
(?<ens> (?> \\{2} )+ ) # even number of backslashes
(?<sqc> (?> [^\s'\\]++ | \s++ (?!'|$) | \g<ens> | \\ '?+ )+ ) # single quotes content
(?<dqc> (?> [^\s"\\]++ | \s++ (?!"|$) | \g<ens> | \\ "?+ )+ ) # double quotes content
(?<con> (?> [^\s"'\\]++ | \s++ (?!["']|$) | \g<ens> | \\ ["']?+ )+ ) # content
)
# Pattern #
\s*+ (?<res> \g<con>)
| ' \s*+ (?<res> \g<sqc>) \s*+ '?+
| " \s*+ (?<res> \g<dqc>) \s*+ "?+
~x
LOD;
$subject = " ok 'that\\'s cool' \"yeah that's \\\"cool\\\"\"";
preg_match_all($pattern, $subject, $matches, PREG_SET_ORDER);
foreach($matches as $match) {
var_dump($match['res']);
}
I made the choice to trim spaces in all results, then " abcd " will give abcd. This pattern allows all backslashes you want, anywhere you want. If a quoted string is not closed at the end of the string, the end of the string is considered as the closing quote (this is why i have made the closing quotes optional). So, abcd " ef'gh will give you abcd and ef'gh
Quite simple problem (but difficult solution): I got a string in PHP like as follows:
['one']['two']['three']
And from this, i must extract the last tags, so i finally got three
it is also possible that there is a number, like
[1][2][3]
and then i must get 3
How can i solve this?
Thanks for your help!
Flo
Your tag is \[[^\]]+\].
3 Tags are: (\[[^\]]+\]){3}
3 Tags at end are: (\[[^\]]+\]){3}$
N Tags at end are: (\[[^\]]+\])*$ (N 0..n)
Example:
<?php
$string = "['one']['two']['three'][1][2][3]['last']";
preg_match("/((?:\[[^\]+]*\]){3})$/", $string, $match);
print_r($match); // Array ( [0] => [2][3]['last'] [1] => [2][3]['last'] )
This tested code may work for you:
function getLastTag($text) {
$re = '/
# Match contents of last [Tag].
\[ # Literal start of last tag.
(?: # Group tag contents alternatives.
\'([^\']+)\' # Either $1: single quoted,
| (\d+) # or $2: un-quoted digits.
) # End group of tag contents alts.
\] # Literal end of last tag.
\s* # Allow trailing whitespace.
$ # Anchor to end of string.
/x';
if (preg_match($re, $text, $matches)) {
if ($matches[1]) return $matches[1]; // Either single quoted,
if ($matches[2]) return $matches[2]; // or non quoted digit.
}
return null; // No match. Return NULL.
}
Here is a regex that may work for you. Try this:
[^\[\]']*(?='?\]$)