Parse a JS script using PHP and REGEX to get a JS variable value

Question

I need to open a JS file from PHP, to find a json var in this file, and convert it to a php array.

Right now I can't figure out which regex to use.

// get the js file
$file = file_get_contents ("http://pve.proxmox.com/pve2-api-doc/apidoc.js");

// extract the json content of var pveapi
if ( preg_match ( "#pveapi = ({[^}]*})#", $file, $infoJson ) ) {
    $arrJson = json_decode ( $infoJson [1], true );
}

// shows nothing so far :((
print_r($arrJson);

I have found few examples to do that, but none would work for me. Anyone with decent skills in regex could help me please ?

Ben

edit: added a part of the js file :

var pveapi = [
   {
      "info" : {
         "GET" : {
            "parameters" : {
               "additionalProperties" : 0
            },
            "permissions" : {
               "user" : "all"
            },
            "returns" : {
               "type" : "array",
               "items" : {
                  "type" : "object",
                  "properties" : {}
               },
               "links" : [
                  {
                     "rel" : "child",
                     "href" : "{name}"
                  }
               ]
            },
            "name" : "index",
            "method" : "GET",
            "description" : "Cluster index."
         }
      }
    }
];

Ext.onReady(function() { ... }

thanks for the answer, i tried but it's still the same, not matching. — Asterix34, Feb 25 '15 at 13:13
if you know that the pveapi you need is the first instance of var pveapi = in your javascript, AND you know that the pveapi does not contain the string Ext.onReady , AND you know that right after the pveapi, there's a Ext.onReady , this should work ... unfortunately i think you'll need a full-fledged javascript interpreter to grab the code reliably — hanshenrik, Feb 25 '15 at 13:32

score 3 · Accepted Answer · answered Feb 25 '15 at 13:13

3

In this case, the end can be found by matching a semicolon at the end of a line:

if (preg_match('/^var pveapi = (.*?);$/ms', $js, $matches)) {
    $data = json_decode($matches[1]);
    print_r($data);
}

answered Feb 25 '15 at 13:13

Ja͢ck

170,779
38
263
309

thanks, this is exactly what i wanted - my account is too young to upvote, but I flagged it as resolved. – Asterix34 Feb 25 '15 at 13:22
and when the pveapi DOES contain a semicolon somewhere? :p – hanshenrik Feb 25 '15 at 13:33
@hanshenrik It may contain a semicolon, just not at the end of a line. – Ja͢ck Feb 25 '15 at 13:34
oh, didn't think about that. still not reliable unless you know the javascript is beautified though, i think~ – hanshenrik Feb 25 '15 at 13:37
@hanshenrik Yeah, it gets trickier if you can't rely on newlines not being part of string values :) – Ja͢ck Feb 25 '15 at 13:40

Flygenring · Answer 2 · 2015-02-25T13:40:47.213

0

Per default the RegEx engine operates greedily on individual lines, so you'd have to tell it to do the opposite – the RegEx you seem to be looking for would be

#\spveapi\s*=\s*(.*?);\s*$#s

What it does is:

#
Start the expression
\s
Make sure the variable name is preceded by whitespace, so it's not part of a different variable name
pveapi
Find the variable
\s*=\s*
Make sure there's an equal sign with optional whitespace around it
(.*?);\s*$
Get as few characters as possible before finding a semicolon – i.e. all characters until the first semicolon that is follow only by optional whitespace and a line ending
#ms
End the expression and tell it to let . match line endings too and match $ to the ending of each line

edited Feb 25 '15 at 13:40

answered Feb 25 '15 at 13:28

Flygenring

3,818
1
32
39

thanks for the answer and the details, there is little typo in your answer in the last part, you meant #ms instead of #s. – Asterix34 Feb 25 '15 at 14:01
Yeah, I saw that my answer could be more complete, so edited it to add the whitespace and line ending to the 'stop clause' and the `m` to use it ;) – Flygenring Feb 25 '15 at 14:09

Parse a JS script using PHP and REGEX to get a JS variable value

2 Answers2