- Last Updated: [[2020-12-04]] - [[JMeter Regular Expression Extractor]] [[Correlation of dynamic values]] - - Here's an example of how to use the regular expression extractor in JMeter to correlate a long string and get two variables out of it. - # Raw data to be parsed - ```javascript {"Id":907,"ShortName":"ReportingHazardIncidentInvestigation","LongName":"Resident Investigation Incident"} ``` - Imagine that there are many more strings like this in the response, and we want to get a random one. - # Put this in the regular expression extractor - ```javascript Reference name: `formcreated` Regular expression: `"Id":([0-9]+),"ShortName":"([^"]+)","LongName":"([^"]+)"` Template: `$1$2$3 Match No. (0 for Random): 0 Default value: NOT_FOUND``` - Using a default value of `NOT_FOUND` or something similarly unique will give you a clue that there was something wrong with the extractor. In contrast, if you don't set a default value, you won't know whether the script has simply not executed the extractor yet or if the extractor failed. - This takes the long string, and saves the groups (those delineated by parentheses) into variables). - # Variables created by the extractor - To be able to see what variables are created by the extractor, use the [[JMeter/Debug Post Processor]]. Here's what was created by the extractor above. - ```javascript formcreated=907ReportingHazardIncidentInvestigationResident Investigation Incident formcreated_g=3 formcreated_g0="Id":907,"ShortName":"ReportingHazardIncidentInvestigation","LongName":"Resident Investigation Incident" formcreated_g1=907 formcreated_g2=ReportingHazardIncidentInvestigation formcreated_g3=Resident Investigation Incident``` - `formcreated` is the entire string, without the selectors having been removed. - The `_g` refers to the number of groups that have been extracted. Each group corresponds to the selectors in the regular expression. (__Note: It's zero-indexed, so 3 actually means 4.__) - # Using the extractor variables - ## In a POST request - ```javascript {"Title":"${formcreated_g2}","DateStart":"${oneyearinfuture}","DateEnd":"Invalid date","TimeDue":"1800","LeadTime":0,"TaskNotes":"testing","CeaseRecurrence":1,"Frequency":0,"ScheduleDefinitionType":2,"FacilityId":${facilityid},"FormId":${formcreated_g1},"ResidentIds":[]} ``` -