I'm making column shortcodes in WordPress and it always add </p> after the tag.
So the raw HTML result from dumping the variable looks like this:
<column class="size-5"></p>
....
</column>
I want to delete that lone </p> with regex, so I made this:
$content = preg_replace("/(?!<column[^<]+)<\/p>/", '', $content);
I matched</p> while excluding the column tag. Here's the Regexr link.
In regexr (which I assume uses JS syntax), it works perfectly. But in PHP, it matches every single </p> and remove it.
I have tried many variation for look behind ?<! and ?>! but doesn't work.
Has anyone experienced this same problem before?
Thanks
First of all, you should know that manipulating HTML with regex is vulnerable and may not work in 100% cases with arbitrary HTML code. You should only use it when you know what you are doing (you generate the HTML yourself in the unique way, or the HTML provider is known and uses a unqiue approach to HTML escaping, etc.).
Next, you do not need to use any negative lookaheads. The pattern you are using matches any </p> that is not a starting subsequence of <column[^<]+ subpattern, which is always true, and you effectively match any </p>.
In case you want to remove some text that appears in some specific known context, you may rely on capturing what you need and just matching what you want to replace. The only thing to do is to enclose the part of pattern you will need to keep with (...) and use a backreference to that group in the replacement pattern.
Use
$content = preg_replace('/(<column\b[^<]*>)<\/p>/', '$1', $content);
Alternatively, in PCRE, you may use \K operator that omits the whole text matched so far like
$content = preg_replace('/<column\b[^<]*>\s*\K<\/p>/', '', $content);
And you won't have to use any backreferences in the replacement pattern.
I added the \b (word boundary) to make sure column is matched as a whole word. Since it still can match column in column-editor, you might want to repace <column\b[^<]*> with <column(?:\s[^<]*)?>.
Related
The regex works perfectly but the problem is it also include the next occurrence instead of ending with the first occurrence then start again from the
Regex : (?=<appView)\s{0,1}(.*)(?<=<\/appView>)
String: <appView></appView> <appView></appView>
But my problem is it eat matches the whole word like
(Match 1)<appView></appView> <appView></appView>
I want it to search the group differently but i cant make it work.
Desired output : (Match 1) <appView></appView> (Match 2)<appView></appView>
\s{0,1} equals \s? You need to use (.*?) to be lazy instead of (.*)
Use this pattern: ~(?=<appView)\s?(.*?)(?<=</appView>)~
Demo Link
*note, you don't have to escape / in the closing tag if you use something other than a slash as your pattern delimiter. I am using ~ at the beginning and end of my pattern to avoid escaping.
I fully recommend to switch from regex to an actual sequential xml parser. Regex is aweful for parsing xml based files, for example because of the problems below.
That said, you can "fix" your regex by using ([^<>]*). This will match all characters without < or >, which will make sure that no other tags are nested inside. If done with all tags, you cannot match something like <appview><unclosedTag></appView>, because it is invalid. If you can be certain that the structure is correct, this is slightly less of an issue.
Another problem your approach has is that if you have nested tags like so: <appView> something <appView> something else </appView> else </appView>, your approach will make you end up with [replaced] else </appView>.
I've searched for this but couldn't find a solution that worked for me.
I need regex pattern that will match all text except html tags, so I can make it cyrilic (which would obviously ruin the entire html =))
So, for example:
<p>text1</p>
<p>text2 <span class="theClass">text3</span></p>
I need to match text1, text2, and text3, so something like
preg_match_all("/pattern/", $text, $matches)
and then I would just iterate over the matches, or if it can be done with preg_replace, to replace text1/2/3, with textA/B/C, that would be even better.
As you probably know, regex is not a great choice for this (the general advice here will be to use a Dom parser).
However, if you needed a quick regex solution, you use this (see demo):
<[^>]*>(*SKIP)(*F)|[^<]+
How this works is that on the left the <[^>]*> matches complete <tags>, then the (*SKIP)(*F) causes the regex to fail and the engine to advance to the position in the string that follows the last character of the matched tag.
This is an application of a general technique to exclude patterns from matches (read the linked question for more details).
If you don't want to allow the matches to span several lines, add \r\n to the negated character class that does your matching, like so:
<[^>]*>(*SKIP)(*F)|[^<\r\n]+
How about this RegEx:
/(?<=>)[\w\s]+(?=<)/g
Online Demo
Maybe this one (in Ruby):
/(?<!<)(?<!<\/)(?<![<\/\w+])([[:alpha:]])+(?!>)/
Enjoy !
Please use PHP DOMDocument class to parse XML content :
PHP Doc
I am looking for a way to replace all string looking alike in entire page with their defined values
Please do not recommend me other methods of including language constants.
Strings like this :
[_HOME]
[_NEWS]
all of them are looking the same in [_*] part
Now the big issue is how to scan a HTML page and to replace the defined values .
One ways to parse the html page is to use DOMDocument and then pre_replace() it
but my main problem is writing a pattern for the replacement
$pattern = "/[_i]/";
$replacement= custom_lang("/i/");
$doc = new DOMDocument();
$htmlPage = $doc->loadHTML($html);
preg_replace($pattern, $replacement, $htmlPage);
In RegEx, [] are operators, so if you use them you need to escape them.
Other problem with your expression is _* which will match Zero or more _. You need to replace it with some meaningful match, Like, _.* which will match _ and any other characters after that. SO your full expression becomes,
/\[_.*?\]/
Hey, why an ?, you might be tempted to ask: The reason being that it performs a non-greedy match. Like,
[_foo] [_bar] is the query string then a greedy match shall return one match and give you the whole of it because your expression is fully valid for the string but a non-greedy match will get you two seperate matches. (More information)
You might be better-off in being more constrictive, by having an _ followed by Capital letters. Like,
/\[_[A-Z]+\]/
Update: Using the matched strings and replacing them. To do so we use the concept called back-refrencing.
Consider modifying the above expression, enclosing the string in parentheses, like, /\[_([A-Z]+)\]/
Now in preg-replace arguments we can use the expression in parentheses by back-referencing them with $1. So what you can use is,
preg_replce("/\[_([A-Z]+)\]/e", "my_wonderful_replacer('$1')", $html);
Note: We needed the e modifier to treat the second parameter as PHP code. (More information)
If you know the full keyword you are trying to replace (e.g. [_HOME]), then you can just use str_replace() to replace all instances.
No need to make things like this more complex by introducing regex.
I am trying to pull the anchor text from a link that is formatted this way:
<h3><b>File</b> : i_want_this</h3>
I want only the anchor text for the link : "i_want_this"
"variable_text" varies according to the filename so I need to ignore that.
I am using this regex:
<a href=\"\/en\/browse\/file\/variable_text\">(.*?)<\/a>
This is matching of course the complete link.
PHP uses a pretty close version to PCRE (PERL Regex). If you want to know a lot about regex, visit perlretut.org. Also, look into Regex generators like exspresso.
For your use, know that regex is greedy. That means that when you specify that you want something, follwed by anything (any repetitions) followed by something, it will keep on going until that second something is reached.
to be more clear, what you want is this:
<a href="
any character, any number of times (regex = .* )
">
any character, any number of times (regex = .* )
</a>
beyond that, you want to capture the second group of "any character, any number of times". You can do that using what are called capture groups (capture anything inside of parenthesis as a group for reference later, also called back references).
I would also look into named subpatterns, too - with those, you can reference your choice with a human readable string rather than an array index. Syntax for those in PHP are (?P<name>pattern) where name is the name you want and pattern is the actual regex. I'll use that below.
So all that being said, here's the "lazy web" for your regex:
<?php
$str = '<h3><b>File</b> : i_want_this</h3>';
$regex = '/(<a href\=".*">)(?P<target>.*)(<\/a>)/';
preg_match($regex, $str, $matches);
print $matches['target'];
?>
//This should output "i_want_this"
Oh, and one final thought. Depending on what you are doing exactly, you may want to look into SimpleXML instead of using regex for this. This would probably require that the tags that we see are just snippits of a larger whole as SimpleXML requires well-formed XML (or XHTML).
I'm sure someone will probably have a more elegant solution, but I think this will do what you want to done.
Where:
$subject = "<h3><b>File</b> : i_want_this</h3>";
Option 1:
$pattern1 = '/(<a href=")(.*)(">)(.*)(<\/a>)/i';
preg_match($pattern1, $subject, $matches1);
print($matches1[4]);
Option 2:
$pattern2 = '()(.*)()';
ereg($pattern2, $subject, $matches2);
print($matches2[4]);
Do not use regex to parse HTML. Use a DOM parser. Specify the language you're using, too.
Since it's in a captured group and since you claim it's matching, you should be able to reference it through $1 or \1 depending on the language.
$blah = preg_match( $pattern, $subject, $matches );
print_r($matches);
The thing to remember is that regex's return everything you searched for if it matches. You need to specify that only care about the part you've surrounded in parenthesis (the anchor text). I'm not sure what language you're using the regex in, but here's an example in Ruby:
string = 'i_want_this'
data = string.match(/<a href=\"\/en\/browse\/file\/variable_text\">(.*?)<\/a>/)
puts data # => outputs 'i_want_this'
If you specify what you want in parenthesis, you can reference it:
string = 'i_want_this'
data = string.match(/<a href=\"\/en\/browse\/file\/variable_text\">(.*?)<\/a>/)[1]
puts data # => outputs 'i_want_this'
Perl will have you use $1 instead of [1] like this:
$string = 'i_want_this';
$string =~ m/<a href=\"\/en\/browse\/file\/variable_text\">(.*?)<\/a>/;
$data = $1;
print $data . "\n";
Hope that helps.
I'm not 100% sure if I understand what you want. This will match the content between the anchor tags. The URL must start with /en/browse/file/, but may end with anything.
#(.*?)#
I used # as a delimiter as it made it clearer. It'll also help if you put them in single quotes instead of double quotes so you don't have to escape anything at all.
If you want to limit to numbers instead, you can use:
#(.*?)#
If it should have just 5 numbers:
#(.*?)#
If it should have between 3 and 6 numbers:
#(.*?)#
If it should have more than 2 numbers:
#(.*?)#
This should work:
<a href="[^"]*">([^<]*)
this says that take EVERYTHING you find until you meet "
[^"]*
same! take everything with you till you meet <
[^<]*
The paratese around [^<]*
([^<]*)
group it! so you can collect that data in PHP! If you look in the PHP manual om preg_match you will se many fine examples there!
Good luck!
And for your concrete example:
<a href="/en/browse/file/variable_text">([^<]*)
I use
[^<]*
because in some examples...
.*?
can be extremely slow! Shoudln't use that if you can use
[^<]*
You should use the tool Expresso for creating regular expression... Pretty handy..
http://www.ultrapico.com/Expresso.htm
Hi Guys I'm very new to regex, can you help me with this.
I have a string like this "<input attribute='value' >" where attribute='value' could be anything and I want to get do a preg_replace to get just <input />
How do I specify a wildcard to replace any number of any characters in a srting?
like this? preg_replace("/<input.*>/",$replacement,$string);
Many thanks
What you have:
.*
will match "any character, and as many as possible.
what you mean is
[^>]+
which translates to "any character, thats not a ">", and there must be at least one
or altertaively,
.*?
which means
"any character, but only enough to make this rule work"
BUT DONT
Parsing HTML with regexps is Bad
use any of the existing html parsers, DOM librarys, anything, Just NOT NAïVE REGEX
For example:
<foo attr=">">
Will get grabbed wrongly by regex as
'<foo attr=" ' with following text of '">'
Which will lead you to this regex:
`<[a-zA-Z]+( [a-zA-Z]+=['"][^"']['"])*)> etc etc
at which point you'll discover this lovely gem:
<foo attr="'>\'\"">
and your head will explode.
( the syntax highlighter verifies my point, and incorrectly matches thinking i've ended the tag. )
Some people were close... but not 100%:
This:
preg_replace("<input[^>]*>", $replacement, $string);
should be this:
preg_replace("<input[^>]*?>", $replacement, $string);
You don't want that to be a greedy match.
preg_replace("<input[^>]*>", $replacement, $string);
// [^>] means "any character except the greater than symbol / right tag bracket"
This is really basic stuff, you should catch up with some reading. :-)
If I understand the question correctly, you have the code:
preg_replace("/<input.*>/",$replacement,$string);
and you want us to tell you what you should use for $replacement to delete what was matched by .*
You have to go about this the other way around. Use capturing groups to capture what you want to keep, and reinsert that into the replacement. E.g.:
preg_replace("/(<input).*(>)/","$1$2",$string);
Of course, you don't really need capturing groups here, as you're only reinserting literal text. Bet the above shows the technique, in case you want to do this in a situation where the tag can vary. This is a better solution:
preg_replace("/<input [^>]*>/","<input />",$string);
The negated character class is more specific than the dot. This regex will work if there are two HTML tags in the string. Your original regex won't.