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How do I get to pick up the contents within an alt tag with regex
Given this text:
<img class="aligncenter" src="myblog.com/wp-content/image.jpg " alt=" I want to get this text " width=" 400 " height="300" />
How do I match I want to get this text
I've tried this alt=".*" but this yields alt=" I want to get this text " width=" 400 " height="300" which is undesirable.
Foreward
You should really use an html parser for this, but you seem to have creative control over the source string, and if it's really this simple then the edge cases should be reduced.
Description
<img\s(?=(?:[^>=]|='[^']*'|="[^"]*"|=[^'"][^\s>]*)*?\salt=['"]([^"]*)['"]?)
(?:[^>=]|='[^']*'|="[^"]*"|=[^'"\s]*)*"\s?\/?>
This regular expression will do the following:
find all the image tags
require the image tag to have a alt attribute
capture the alt attribute value and put into the capture group 1
allow the value to be surrounded in single, double, or no quotes
avoid some pretty difficult edge cases which would make matching HTML difficult
Example
Live Demo
https://regex101.com/r/cN0lD4/2
Sample text
Note the difficult edge case in the second img tag.
<img class="aligncenter" src="myblog.com/wp-content/image.jpg" alt=" I want to get this text" width =" 400 " height="300" />
<img onmouseover=' alt="This is not the droid you are looking for" ;' class="aligncenter" src="myblog.com/wp-content/image.jpg" alt="This is the droid I'm looking for." width =" 400 " height="300" />
Sample Matches
Capture group 0 gets the entire img tag
Capture group 1 gets just the value in the alt attribute, not including any surrounding quotes
[0][0] = <img class="aligncenter" src="myblog.com/wp-content/image.jpg" alt=" I want to get this text" width =" 400 " height="300" />
[0][1] = I want to get this text
[1][0] = <img onmouseover=' alt="This is not the droid you are looking for" ;' class="aligncenter" src="myblog.com/wp-content/image.jpg" alt="This is the droid I'm looking for." width =" 400 " height="300" />
[1][1] = This is the droid I'm looking for.
Explanation
NODE EXPLANATION
----------------------------------------------------------------------
<img '<img'
----------------------------------------------------------------------
\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
----------------------------------------------------------------------
\s whitespace (\n, \r, \t, \f, and " ")
----------------------------------------------------------------------
alt= 'alt='
----------------------------------------------------------------------
['"] any character of: ''', '"'
----------------------------------------------------------------------
( group and capture to \1:
----------------------------------------------------------------------
[^"]* any character except: '"' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
) end of \1
----------------------------------------------------------------------
['"]? any character of: ''', '"' (optional
(matching the most amount possible))
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?: 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
----------------------------------------------------------------------
= '='
----------------------------------------------------------------------
[^'"\s]* any character except: ''', '"',
whitespace (\n, \r, \t, \f, and " ") (0
or more times (matching the most amount
possible))
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
" '"'
----------------------------------------------------------------------
\s? whitespace (\n, \r, \t, \f, and " ")
(optional (matching the most amount
possible))
----------------------------------------------------------------------
\/? '/' (optional (matching the most amount
possible))
----------------------------------------------------------------------
> '>'
----------------------------------------------------------------------
Thanks to those who helped solved this:
'/<img.*?alt="(.*?)".*>/'
Related
i am using preg_split("/\"[^\"]*\"(*SKIP)(*F)|\x20/", $input_line); and run it on phpliveregex.com
it produce array :
array(10
0=><b>test</b>
1=>or
2=><em>oh
3=>yeah</em>
4=>and
5=><i>
6=>oh
7=>yeah
8=></i>
9=>"ye we 'hold' it"
)
NOT what i want, it should be seperate by spaces only outside html tags like this:
array(5
0=><b>test</b>
1=>or
2=><em>oh yeah</em>
3=>and
4=><i>oh yeah</i>
5=>"ye we 'hold' it"
)
in this regex i am only can add exception in "double quote" but realy need help to add more, like tag <img/><a></a><pre></pre><code></code><strong></strong><b></b><em></em><i></i>
any explanation about how that regex works also appreciate.
It's easier to use the DOMDocument since you don't need to describe what a html tag is and how it looks. You only need to check the nodeType. When it's a textNode, split it with preg_match_all (it's more handy than to design a pattern for preg_split):
$html = 'spaces in a text node <b>test</b> or <em>oh yeah</em> and <i>oh yeah</i>
"ye we \'hold\' it"
"unclosed double quotes at the end';
$dom = new DOMDocument;
$dom->loadHTML('<div>' . $html . '</div>', LIBXML_HTML_NOIMPLIED);
$nodeList = $dom->documentElement->childNodes;
$results = [];
foreach ($nodeList as $childNode) {
if ($childNode->nodeType == XML_TEXT_NODE &&
preg_match_all('~[^\s"]+|"[^"]*"?~', $childNode->nodeValue, $m))
$results = array_merge($results, $m[0]);
else
$results[] = $dom->saveHTML($childNode);
}
print_r($results);
Note: I have chosen a default behaviour when a double quote part stays unclosed (without a closing quote), feel free to change it.
Note2: Sometimes LIBXML_ constants are not defined. You can solve this problem testing it before and defining it when needed:
if (!defined('LIBXML_HTML_NOIMPLIED'))
define('LIBXML_HTML_NOIMPLIED', 8192);
Description
Instead of using a split command just match the sections you want
<(?:(?:img)(?=[\s>\/])(?:[^>=]|=(?:'[^']*'|"[^"]*"|[^'"\s>]*))*\s?\/?>|(a|span|pre|code|strong|b|em|i)(?=[\s>\\])(?:[^>=]|=(?:'[^']*'|"[^"]*"|[^'"\s>]*))*\s?\/?>.*?<\/\1>)|(?:"[^"]*"|[^"<]*)*
Example
Live Demo
https://regex101.com/r/bK8iL3/1
Sample text
Note the difficult edge case in the second paragraph
<b>test</b> or <strong> this </strong><em> oh yeah </em> and <i>oh yeah</i> Here we are "ye we 'hold' it"
some<img/>gfsf<a html="droids.html" onmouseover=' var x=" Not the droid I am looking for " ; '>droides</a><pre></pre><code></code><strong></strong><b></b><em></em><i></i>
Sample Matches
MATCH 1
0. [0-11] `<b>test</b>`
MATCH 2
0. [11-15] ` or `
MATCH 3
0. [15-38] `<strong> this </strong>`
MATCH 4
0. [38-56] `<em> oh yeah </em>`
MATCH 5
0. [56-61] ` and `
MATCH 6
0. [61-75] `<i>oh yeah</i>`
MATCH 7
0. [75-111] ` Here we are "ye we 'hold' it" some`
MATCH 8
0. [111-117] `<img/>`
MATCH 9
0. [117-121] `gfsf`
MATCH 10
0. [121-213] `<a html="droids.html" onmouseover=' var x=" Not the droid I am looking for " ; '>droides</a>`
MATCH 11
0. [213-224] `<pre></pre>`
MATCH 12
0. [224-237] `<code></code>`
MATCH 13
0. [237-254] `<strong></strong>`
MATCH 14
0. [254-261] `<b></b>`
MATCH 15
0. [261-270] `<em></em>`
MATCH 16
0. [270-277] `<i></i>`
Explanation
NODE EXPLANATION
----------------------------------------------------------------------
< '<'
----------------------------------------------------------------------
(?: group, but do not capture:
----------------------------------------------------------------------
(?: group, but do not capture:
----------------------------------------------------------------------
img 'img'
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
(?= look ahead to see if there is:
----------------------------------------------------------------------
[\s>\/] any character of: whitespace (\n, \r,
\t, \f, and " "), '>', '\/'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[^>=] any character except: '>', '='
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
= '='
----------------------------------------------------------------------
(?: group, but do not capture:
----------------------------------------------------------------------
' '\''
----------------------------------------------------------------------
[^']* 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
----------------------------------------------------------------------
[^'"\s>]* any character except: ''', '"',
whitespace (\n, \r, \t, \f, and "
"), '>' (0 or more times (matching
the most amount possible))
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
\s? whitespace (\n, \r, \t, \f, and " ")
(optional (matching the most amount
possible))
----------------------------------------------------------------------
\/? '/' (optional (matching the most amount
possible))
----------------------------------------------------------------------
> '>'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
( group and capture to \1:
----------------------------------------------------------------------
a 'a'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
span 'span'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
pre 'pre'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
code 'code'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
strong 'strong'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
b 'b'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
em 'em'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
i 'i'
----------------------------------------------------------------------
) end of \1
----------------------------------------------------------------------
(?= look ahead to see if there is:
----------------------------------------------------------------------
[\s>\\] any character of: whitespace (\n, \r,
\t, \f, and " "), '>', '\\'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[^>=] any character except: '>', '='
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
= '='
----------------------------------------------------------------------
(?: group, but do not capture:
----------------------------------------------------------------------
' '\''
----------------------------------------------------------------------
[^']* 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
----------------------------------------------------------------------
[^'"\s>]* any character except: ''', '"',
whitespace (\n, \r, \t, \f, and "
"), '>' (0 or more times (matching
the most amount possible))
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
\s? whitespace (\n, \r, \t, \f, and " ")
(optional (matching the most amount
possible))
----------------------------------------------------------------------
\/? '/' (optional (matching the most amount
possible))
----------------------------------------------------------------------
> '>'
----------------------------------------------------------------------
.*? any character (0 or more times (matching
the least amount possible))
----------------------------------------------------------------------
< '<'
----------------------------------------------------------------------
\/ '/'
----------------------------------------------------------------------
\1 what was matched by capture \1
----------------------------------------------------------------------
> '>'
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
(?: group, but do not capture (0 or more times
(matching the most amount possible)):
----------------------------------------------------------------------
" '"'
----------------------------------------------------------------------
[^"]* 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))
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
I want to create a proper preg_match pattern to extract all <link *rel="stylesheet"* /> within the <head> of some webpages. So this pattern: #<link (.+?)>#is worked fine until I realized it catches also the <link rel="shortcut icon" href="favicon.ico" /> that's in the <head>. So I want to alter the pattern so that it makes sure there IS the word stylesheet somewhere WITHIN the link. I think it needs to use some lookaround but I'm not sure how to do it. Any help will be much appreciated.
Here we go again... don't use a regex to parse html, use an html parser like PHP DOMDocument.
Here's an example of how to use it:
$html = file_get_contents("https://stackoverflow.com");
$dom = new DOMDocument();
libxml_use_internal_errors(true);
$dom->loadHTML($html);
$xpath = new DOMXpath($dom);
foreach ($xpath->query("//link[#rel='stylesheet']") as $link)
{
echo $link->getAttribute("href");
}
PHPFiddle Demo
To do this with regular expressions, it would be best to do this as a two part operation, the first part is to separate out the head from the body to ensure you're only working within the head.
Then second part will parse the head looking for the desired links
Parsing Links
<link\s*(?=(?:[^>=]|='[^']*'|="[^"]*"|=[^'"][^\s>]*)*?rel=['"]?stylesheet)(?:[^>=]|='(?:[^']|\\')*'|="(?:[^"]|\\")*"|=[^'"][^\s>]*)*\s*>
This expression will do the following:
find all the <link tags
ensure the link tag has the desired attribute rel='stylesheet
allow attribute values to have single, double or no quotes
avoid messy and difficult edge cases that the HTML Parse Police cry about
Example
Live Demo
https://regex101.com/r/hC5dD0/1
Sample Text
Note the difficult edge case in the last line.
<link *rel="stylesheet"* />
<link rel="shortcut icon" href="favicon.ico" />
<link onmouseover=' rel="stylesheet" ' rel="shortcut icon" href="favicon.ico">
Sample Matches
<link *rel="stylesheet"* />
Explanation
NODE EXPLANATION
----------------------------------------------------------------------
<link '<link'
----------------------------------------------------------------------
\s* whitespace (\n, \r, \t, \f, and " ") (0 or
more times (matching the most amount
possible))
----------------------------------------------------------------------
(?= 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
----------------------------------------------------------------------
rel= 'rel='
----------------------------------------------------------------------
['"]? any character of: ''', '"' (optional
(matching the most amount possible))
----------------------------------------------------------------------
stylesheet 'stylesheet'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?: group, but do not capture (0 or more times
(matching the most amount possible)):
----------------------------------------------------------------------
[^>=] any character except: '>', '='
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
=' '=\''
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[^'] any character except: '''
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
\\ '\'
----------------------------------------------------------------------
' '\''
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
' '\''
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
=" '="'
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[^"] any character except: '"'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
\\ '\'
----------------------------------------------------------------------
" '"'
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
" '"'
----------------------------------------------------------------------
| 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
----------------------------------------------------------------------
\s* whitespace (\n, \r, \t, \f, and " ") (0 or
more times (matching the most amount
possible))
----------------------------------------------------------------------
> '>'
----------------------------------------------------------------------
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]]
example here
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);
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] ">
the captured substring will not include the wrapping square brackets
allow any tag name, or replace the \w with the desired tag names
allow value to 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]>
[value 6]
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
----------------------------------------------------------------------
\] ']'
I have a large XML file with products inside. I'm trying to delete all products which are out of stock. File size is over 20MB.
<product>
<name>bla1</name>
<price>50$</price>
<stock>yes</stock>
<description>bla</description>
</product>
<product>
<name>bla2</name>
<price>60$</price>
<stock>no</stock>
<description>bla</description>
</product>
...
Is it possible to delete them using Notepad++'s regex or should I use simpleXML(PHP) or something similar?
My basic PHP code:
$url = 'input/products.xml';
$xml = new SimpleXMLElement(file_get_contents($url));
foreach ($xml->product->children() as $product) {
//finding out of stock products and deleting them
}
$xml->asXml('output/products.xml');
Forward
Doing pattern matching via regular expression is not ideal, if you have access to PHP, then I recommend using a proper HTLM parsing tool. With that said, I offer a solution you can use in Notepad++
Description
<product\s*(?:[^>=]|='[^']*'|="[^"]*"|=[^'"][^\s>]*)*?\s?\/?>(?:(?!</product).)*<stock\s*(?:[^>=]|='[^']*'|="[^"]*"|=[^'"][^\s>]*)*?\s?\/?>no</stock>(?:(?!</product).)*<\/product>
Replace with: nothing
To view the image better, you can right click it and select view in new window.
This Regular Expression will do the following:
find the entire product section
require the subtag stock
require the subtag stock to have a value of no
avoid extremely edge cases that makes pattern matching in HTML difficult
From Notepad ++
From Notepad++, note that you should be using notpad++ version 6.1 or later as there were problems with regular expressions in an older version that have been solved now.
press the ctrlh to enter the find and replace
mode
Select the Regular Expression option
In the "Find what" field place the regular expression
in the "Replace with" field enter ``
Click Replace all
Example
Live Demo
https://regex101.com/r/cW9nC5/1
Sample text
<product>
<name>bla1</name>
<price>50$</price>
<stock>yes</stock>
<description>bla</description>
</product>
<product>
<name>bla2</name>
<price>60$</price>
<stock>no</stock>
<description>bla</description>
</product>
After Replace
<product>
<name>bla1</name>
<price>50$</price>
<stock>yes</stock>
<description>bla</description>
</product>
Explanation
NODE EXPLANATION
----------------------------------------------------------------------
<product '<product'
----------------------------------------------------------------------
\s* whitespace (\n, \r, \t, \f, and " ") (0 or
more times (matching the most amount
possible))
----------------------------------------------------------------------
(?: 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
----------------------------------------------------------------------
\s? whitespace (\n, \r, \t, \f, and " ")
(optional (matching the most amount
possible))
----------------------------------------------------------------------
\/? '/' (optional (matching the most amount
possible))
----------------------------------------------------------------------
> '>\r\n'
----------------------------------------------------------------------
(?: group, but do not capture (0 or more times
(matching the most amount possible)):
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
</product '</product'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
. any character except \n
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
<stock '<stock'
----------------------------------------------------------------------
\s* whitespace (\n, \r, \t, \f, and " ") (0 or
more times (matching the most amount
possible))
----------------------------------------------------------------------
(?: 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
----------------------------------------------------------------------
\s? whitespace (\n, \r, \t, \f, and " ")
(optional (matching the most amount
possible))
----------------------------------------------------------------------
\/? '/' (optional (matching the most amount
possible))
----------------------------------------------------------------------
>no</stock> '>no</stock>'
----------------------------------------------------------------------
(?: group, but do not capture (0 or more times
(matching the most amount possible)):
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
</product '</product'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
. any character except \n
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
< '<'
----------------------------------------------------------------------
\/ '/'
----------------------------------------------------------------------
product> 'product>'
----------------------------------------------------------------------
I guess notepad++ will be easier, i.e.:
FIND : <product>\s+<name>.*?<\/name>\s+<price>.*?<\/price>\s+<stock>no<\/stock>\s+<description>.*?\/description>\s+<\/product>
REPLACE : with nothing
DEMO
https://regex101.com/r/fH0mM7/1
NOTE
Make sure you checkRegular Expression at the bottom
You can do this with PHP using the below code
<?php
$url = 'input/products.xml';
$xml = new SimpleXMLElement(file_get_contents($url));
$i = count($xml) - 1;
for ($i; $i >= 0; --$i) {
$product = $xml->product[$i];
if ($product->stock == "no") {
unset($xml->product[$i]);
}
}
$xml->asXml('output/products.xml');
?>
I am really bad in regex expression,
there is below code i saw in my existing application in php but not really understanding what it is doing.
$content = preg_replace('/(<?xml[^>]*)encoding=["\']([^>"\']*)?["\']([^>]*?>)/', '$1encoding="' . $encoding . '"$3', $content);
return $content;
If any expert can share some info that would be really great.
Update
Trying to run this but not working is there anything i am missing here..
$encoding = 'UTF-32';
$content = '<?xml version="1.0" encoding="UTF-8" ?><rss version="2.0" xmlns:media="http://search.yahoo.com/mrss/" xmlns:atom="http://www.w3.org/2005/Atom">
<channel></channel>';
echo preg_replace('/(<?xml[^>]*)encoding=["\']([^>"\']*)?["\']([^>]*?>)/', '$1encoding="' . $encoding . '"$3', $content);
update
It may sound stupid.. but it was working... as it is XML tag so for that i need to do display source in chrome and it will display it...
Thank you everyone.. specially M42
regards,
Mona
It will change the encoding present in the file by a new one contained in the variable $encoding
Example:
<?xml blah blah encode="XXX" blah blah?>
will be changed to (assuming $encoding='UTF-8';):
<?xml blah blah encode="UTF-8" blah blah?>
$1 contains: <xml blah blah
$3 contains: blah blah>
The result is the concatenation of $1, encode="UTF-8" and $3.
Regex explanation:
The regular expression:
(<?xml[^>]*)encoding=["\']([^>"\']*)?["\']([^>]*?>)
matches as follows:
NODE EXPLANATION
----------------------------------------------------------------------
( group and capture to \1:
----------------------------------------------------------------------
<? '<' (optional (matching the most amount
possible))
----------------------------------------------------------------------
xml 'xml'
----------------------------------------------------------------------
[^>]* any character except: '>' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
) end of \1
----------------------------------------------------------------------
encoding= 'encoding='
----------------------------------------------------------------------
["\'] any character of: '"', '\''
----------------------------------------------------------------------
( group and capture to \2 (optional
(matching the most amount possible)):
----------------------------------------------------------------------
[^>"\']* any character except: '>', '"', '\'' (0
or more times (matching the most amount
possible))
----------------------------------------------------------------------
)? end of \2 (NOTE: because you are using a
quantifier on this capture, only the LAST
repetition of the captured pattern will be
stored in \2)
----------------------------------------------------------------------
["\'] any character of: '"', '\''
----------------------------------------------------------------------
( group and capture to \3:
----------------------------------------------------------------------
[^>]*? any character except: '>' (0 or more
times (matching the least amount
possible))
----------------------------------------------------------------------
> '>'
----------------------------------------------------------------------
) end of \3
----------------------------------------------------------------------