In this article, we will discuss about the next set of JMeter elements i.e Pre-Processors and Post-Processors. Lets discuss in detail, how do we use these elements to build a effective test scripts . In case if you have missed the older articles click here.
Pre Processor Elements
A Pre-Processor elements executes some action prior to a Sampler Request being made. If a Pre-Processor is attached to a Sampler element, then it will execute just prior to that sampler element running. A Pre-Processor is most often used to modify the settings of a Sample Request just before it runs, or to update variables that aren’t extracted from response text.
Post Processor Elements
A Post-Processor elements executes some action after a Sampler Request has been made. If a Post-Processor is attached to a Sampler element, then it will execute just after that sampler element runs. A Post-Processor is most often used to process the response data, often to extract values from it.
Execution order of the Elements:
Lets understand in which order JMeter process the elements when multiple elements are added to the thread group.
Please note that Timers, Assertions, Pre- and Post-Processors are only processed if there is a sampler to which they apply. Logic Controllers and Samplers are processed in the order in which they appear in the tree. Other test elements are processed according to the scope in which they are found, and the type of test element.