如何将json嵌套在双方括号中？

Question

Here is my sample:

dummy json: {json here: "asdas"}
[[table
  {json here: "asdas"}
]]
[[pre 
  {json here: "asdasx"}
]]
[[text {json here: "red"} ]]

and I want output like below:

{json here: "asdas"}
{json here: "asdasx"}
{json here: "red"}

UPDATE the json strings may contain curly brackets.

I just want to get all of the json strings, but I keep failing.
I've tried using #\\[\\[(table|pre|text).+({.*?}).+\\]\\]#s but I got the following output:

array(3) {
  [0]=>
  array(1) {
    [0]=>
    string(126) "[[table
      {json here: "asdas"}
    ]]
    [[pre 
      {json here: "asdasx"}
    ]]
    [[text {json here: "red"} ]]"
  }
  [1]=>
  array(1) {
    [0]=>
    string(5) "table"
  }
  [2]=>
  array(1) {
    [0]=>
    string(18) "{json here: "red"}"
  }
}

and btw I'm using php syntax preg_match_all to do above test.

Answer 1

I was able to get your code working by altering your regex to this:

\[\[(?:table|pre|text)\s*(\{.*?\})\s*\]\]

Note carefully that brackets need to be escaped if you intend for them to be literal; you weren't doing this in the regex you showed us.

Code:

$userinfo = "[[table  {json here: \"asdas\"}]] [[pre {json here: \"asdasx\"}]] [[text {json here: \"red\"} ]]";
preg_match_all ("/\[\[(?:table|pre|text)\s*(\{.*?\})\s*\]\]/", $userinfo, $pat_array);
print $pat_array[1][0]." <br> ".$pat_array[1][1]." <br> ".$pat_array[1][2];

Output:

{json here: "asdas"} <br> {json here: "asdasx"} <br> {json here: "red"}

Demo here:

Rextester

Answer 2

This is the fastest and simplest pattern: \\[\\[\\S+\\s+\\K{.*} ( Pattern Demo )

Explanation:

\[\[  #Match 2 opening square brackets
\S+   #Match 1 or more non-white-space characters
\s+   #Match 1 or more white-space characters
\K    #Start the fullstring match from this point (avoiding capture group)
{.*}  #Greedily match 0 or more non-line-terminating characters wrapped in curly brackets

*The curly brackets do not need to be escaped in my pattern because they are not mistaken for quantifiers.

Given the input value in my code to follow ( $in ), my pattern takes just 33 steps. Tim's pattern takes 116 steps and uses a capture group which makes preg_match_all() 's output array twice as big. inarilo's pattern takes 125 steps and uses a capture group.

If anyone particularly wants to have a capture group, this can be used: /\\[\\[\\S+\\s+({.*})/ costing just 36 steps.

Code ( PHP Demo ):

$in='dummy json: {json here: "asdas"}
[[table
  {json here: "asd{as}"}
]]
[[pre 
  {json here: "asdasx"}
]]
[[text {json here: "red"} ]]';

echo implode('<br>',(preg_match_all('/\[\[\S+\s+\K{.*}/',$in,$out)?$out[0]:[]));

Output:

{json here: "asd{as}"}<br>{json here: "asdasx"}<br>{json here: "red"}

Answer 3

Try this regex:

#^\[\[(?:table|pre|text)\s+(\{.*?\})\s+\]\]$#m

Removed the global modifier since you are using preg_match_all.

Answer 4

Following should work:

(\[\[[(table|pre|text) ]*[\n ].*)({.*})

https://regex101.com/r/Yv67gb/1

This narrow down the sample to start with [[table or [[pre or [[text and then start the json with { which ends with } containing and text in between.

Group 2 will be our result.

{json here: "asdas"}
{json here: "asdasx"}
{json here: "red"}