正则表达式仅匹配第一个内容

Question

I have the following html code.

<script type="application/ld+json">
    {"foo" : "bar"}
</script>

<script type="application/ld+json">
    {"foo" : "bar"}
</script>

<script type="application/ld+json">
    {"foo" : "bar"}
</script>

I am trying to grab the json content from inside the first script. But if I do

/<script type="application\/ld\+json">{.*}<\/script>/

it gives everything before the first script opening tag and the last script closing tag. if I do

/<script type="application\/ld\+json">{.*?}<\/script>/

for some reason, I only get the second part.

Is there anyway to get the {} json part from the first tag?

Answer 1

that should not even compile.. but anyway looks like you confused greedy and nongreedy and the type of brackets, {X} means that the group before can be there x amount of time, and not whatever is in x any amount of time that's []*

what you need is something like this

/<script type="application\/ld\+json">[^\{]*?{(.*?)\}[^\}]*?<\/script>/s

Use the object index 1 in the match object returned from the preg_match and you will have your JSON.

repl.it for a running PHP example(code below): https://repl.it/GNdD/0

link to try the regex out: https://regex101.com/r/AouzRm/10

$in = '<script type="application/ld+json">';
$in .= '{"foo" : "bar"}';
$in .= '</script>';

$in .= '<script type="application/ld+json">';
$in .= '    {"foo" : { "bar" : "boo" } }';
$in .= '</script>';

$in .= '<script type="application/ld+json">';
$in .= '    {"foo" : { "bar" : { "boo" : "goo" }}}';
$in .= '</script>';

$matches = [];
$allMatches = [];

preg_match('/<script type="application\/ld\+json">[^\{]*?{(.*?)\}[^\}]*?<\/script>/s',$in,$matches);
preg_match_all('/<script type="application\/ld\+json">[^\{]*?{(.*?)\}[^\}]*?<\/script>/s',$in,$allMatches);

echo "from the preg_match:\n";
print_r("$matches[1]\n\n");

echo "from the preg_match_all:\n";
print_r($allMatches[1]);

Answer 2

As @Denziloe said, your regex looks alright.

It might be a problem with the fact you are not accounting for newlines and whitespace within the script tags.

Check this example and see if that fixes it, otherwise there is probably something wrong with your implementation. I also think you want to add a capture group like I did to have easier access to the JSON part itself

<script type="application\\/ld\\+json">\\s*({.*?})\\s*<\\/script> working example

Answer 3

Try using the following regex :

(?s)>.*?(?={)\K.*?}

see regex demo / explanation

PHP ( demo )

$r = '/(?s)>.*?(?={)\K.*?}/';
$s = '<script type="application/ld+json">
    {"foo1" : "bar1"}
</script>

<script type="application/ld+json">
    {"foo2" : "bar2"}
</script>

<script type="application/ld+json">
    {"foo3" : "bar3"}
</script>';
preg_match($r, $s, $o);
print_r($o);

Answer 4

From a PHP standpoint... Maybe you're not accessing $matches correctly? Assuming you'd want {"one" : "bar"} from the following example

<?php

$html = '<script type="application/ld+json">
    {"one" : "bar"}
</script>

<script type="application/ld+json">
    {"two" : "bar"}
</script>

<script type="application/ld+json">
    {"three" : "bar"}
</script>';

$pattern = '/<script type="application\/ld\+json">\s*(\{.*?\})\s*<\/script>/s';

preg_match_all($pattern, $html, $matches);

$whatYouWant = $matches[1][0];

echo $whatYouWant;

You can see the execution of this code here