title: What's the best method to catenate together multiple input parameters in Robot Framework?
body: <p>I am trying to minimize my Robot Keywords and in my URL testing I sometimes have to build up a URL from a group of inputs, that can vary depending on the test.  The length can be anywhere from 4 to 7 input parameters that I am catenating to pass back one URL with whatever input parameters are passed in.</p>
  
  <p>If I have a keyword that does the following:</p>
  
  <pre><code>inputs: ${location01} ${location02} ${location03}=${EMPTY} ${location04}=${EMPTY}
  ${my_url} = Catenate SEPARATOR=/ ${location01} ${location02} ${location03} ${location04}
  [Return] ${my_url}
  </code></pre>
  
  <p>What is the best method to test if ${location03} is empty, and I can therefore skip the rest?</p>
  
  <p>When I have tried to test for ${EMPTY}, so that the following will be false</p>
  
  <pre><code>${my_url} Run Keyword IF '${location03}'!='${EMPTY} Catenate SEPARATOR=/ ${location01} ${location02} ${location03} ${location04}
  </code></pre>
  
  <p>I still get a catenated string but end up with extra /'s at the end, so ${my_url} looks like:</p>
  
  <pre><code>${my_url} = ${location01}/${location02}//
  </code></pre>
  
  <p>When I want:</p>
  
  <pre><code>${my_url} = ${location01}/${location02}
  </code></pre>
  
  <p>I may be missing how Robot is doing checks, and initializing my variables, I'm sure there is a way to do this that is eluding me at the moment.</p>