Testing ASP.NET Web pages will require two hidden fields (_VIEWSTATE and _EVENTVALIDATION) to be passed for subsequent requests to a web page once the hidden fields have been set in the body. This can be achieved by creating two post Processor elements of the type 'Regular Expression Extractor' and then setting the details of the Regular Expressions as follows:
Response Field to check: Body
Reference Name: VIEWSTATE
Regular Expression: id="_VIEWSTATE" value="([\\w/-_].+)"
Template: $1$
Match No. : 1
Default Value: NOT FOUND
Response Field to check: Body
Reference Name: EVENTVALIDATION
Regular Expression: id="_EVENTVALIDATION" value="([\\w/-_].+)"
Template: $1$
Match No. : 1
Default Value: NOT FOUND
Then in order to ensure these extracted values are passed in subsequent HTTP requests, for each request specify the following to be the Send Parameters for the Request:
Name: _VIEWSTATE
Value: ${VIEWSTATE}
Name: _EVENTVALIDATION
Value: ${EVENTVALIDATION}
Additional Note: (FrankZimper) When testing an ASP.NET 2.0 site I had to add an additional leading underscore to the id fields in the regexes. Is the number of underscores dependent on the version of ASP.NET?
Additional Note: (EmmanuelGuyot) What about the cases where VIEWSTATE is split into different part ? The field VIEWSTATEFIELDCOUNT is easy, but as _''_VIEWSTATExx fields number varies, is it possible to set a dynamic NAME in the Request ?
Additional Note: (SonamChauhan) Concurring with FrankZimper - while testing an ASP.NET 2.0 site, the fields it used had two leading underscores. I used regexs to extract and pass three fields between ASP.NET pages: +PREVIOUSPAGE, +VIEWSTATE, __EVENTVALIDATION. These fields existed on all the ASP.NET pages, either cleanly stored in hidden HTML form fields, or in a couple of instances, strangely jammed in as invisible parts of the DOM using a weird, pipe-delimited syntax.
For extracting out hidden form fields, I used a simpler regular expression than the one in the article: id="+PREVIOUSPAGE"\s*value="(.*?)". For pages that had 'jammed-in' pipe-delimited data, I use this type of regular expression instead: |+PREVIOUSPAGE|(.*?)|
Note the '?' used to specify non-greedy regular-expression matching. I'm reluctant to replace the one in the main article, unless I know the reason for it.
I normally strip the automatically-generated 'Browser-derived headers' HTTP Header Manager element from my scripts. I found that doing so with the ASP.NET site resulted in page load errors. I can only ASP.NET assume uses the Header referrer for some strange reason. So, you may have to keep the 'Browser-derived headers' in.