Tip #13: Checking for empty variable using IF controller

Sometimes you need to add HTTP samplers with dynamic URL or with dynamic part of the URL which are stored in some variable after HTTP sampler post-processing.

But if Regular Expression Extractor will not find any matching string result variable will be set to default value (empty value in our case). We should test this variable for emptyness before we will use it.

Now if the News page has not any news we are sure that JMeter will handle this situation correctly.

Tip #12: How to add HTTP Request sampler with dynamic URL

If you need to add HTTP Request sampler with dynamic URL that can be different each time from testing to testing you must use one of the Post-Processors offered by JMeter. I usually use Regular Expression Extractor for this purposes.

So, let's imaging that you have "Popular News" web page which contains the links to "News Story" web pages that contains the full texts of news and you want to write a test which will include both "News" page and random "News Story" page.

For this you must include "News" page HTTP Request sampler inside Simple Controller with a Regular Expression Extractor to store random "News Story" page URL to a variable:

Then use the variable with the stored random "News Story" page URL in "News Story" HTTP sampler: