[Qt-interest] Problem with RegExp extraction value from Json kind of response

[Denis Akhmetzyanov]

P.S. QRegExp doesn't support using a question mark after the quantifier to
make him lazy. The note from QRegExp documentation:

Notes for Perl Users
...

Non-greedy matching cannot be applied to individual quantifiers, but can be
applied to all the quantifiers in the pattern. For example, to match the
Perl regexp *ro+?m* requires:

 QRegExp rx("ro+m");
 rx.setMinimal(true);

Therefore don't move out '?' (it's my fault), simply remove it :)


2010/3/25 Denis Akhmetzyanov <dakhmetzyanov at smartlabs.tv>

> Hello!
> You should move '?' out of the parentheses (i.e. 'one or zero key') and
> remove '\' before ':' (because this 'unknown escape sequence'). Also set
> QRegExp::setMinimal(true) - because QRegExp is greedy by default and matched
> all characters until last comma. Then code:
>
>     QString http_response =
> "{\"key\":\"a99fdd865c2-10000\",\"oid\":1000055,\"expires\":0000,\"secret\":\"509c03edfdc7\",\"sign\":\"f0dd9e5226d0e77\"}";
>     // or even if i use QRegExp::escape on the string it dosn't work
>     QRegExp rx("\"key\":(.*)?\",");
>     rx.setMinimal(true);
>     int yy = rx.indexIn(http_response);
>     QString cap = rx.cap(1);
>
>     qDebug() << yy; // prints '1'
>     qDebug() << cap; // prints '"a99fdd865c2-10000'
>
>
> 2010/3/25 Meir Yanovich <meiry242 at gmail.com>
>
>> Hello all
>> im trying to extract value by key from http Json kind of struct by  using
>> simple RegExp
>> here is my code i like to extract the key value from the string:
>>
>> QString http_response =
>> "{\"key\":\"a99fdd865c2-10000\",\"oid\":1000055,\"expires\":0000,\"secret\":\"509c03edfdc7\",\"sign\":\"f0dd9e5226d0e77\"}";
>> // or even if i use QRegExp::escape on the string it dosn't work
>> QRegExp rx("\"key\"\:(.*?)\",");
>> int yy = rx.indexIn(http_response);
>> QString cap = rx.cap(1);
>>
>> but i cant capture the string and the yy variable always gives me -1
>> i tested this regexp in this regexp tester : http://gskinner.com/RegExr/and its working fine
>> what im doing wrong here ?
>>
>>
>> _______________________________________________
>> Qt-interest mailing list
>> Qt-interest at trolltech.com
>> http://lists.trolltech.com/mailman/listinfo/qt-interest
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.qt-project.org/pipermail/qt-interest-old/attachments/20100325/5112bf96/attachment.html