title: Extract multiple columns from list of lists, and save in data.frame
body: <p>I have the following list:</p>
  
  <pre><code>library(rjson)
  j &lt;- fromJSON(file='https://esgf-data.dkrz.de/esg-search/search/?offset=0&amp;limit=1000&amp;type=Dataset&amp;replica=false&amp;latest=true&amp;project=CORDEX&amp;domain=EUR-11&amp;experiment=rcp85&amp;time_frequency=day&amp;facets=rcm_name%2Cproject%2Cproduct%2Cdomain%2Cinstitute%2Cdriving_model%2Cexperiment%2Cexperiment_family%2Censemble%2Crcm_version%2Ctime_frequency%2Cvariable%2Cvariable_long_name%2Ccf_standard_name%2Cdata_node&amp;format=application%2Fsolr%2Bjson')
  </code></pre>
  
  <p>I am interested in extracting data from this component: <code>j$response$docs</code>, which is a list of lists. The 'internal'  lists are all supposed to have the same names.</p>
  
  <p>I want to save the output to a <code>data.frame()</code> or <code>tibble()</code>.</p>
  
  <p>This below works and gives the desired output, for the few selected variables:</p>
  
  <pre><code>nmod &lt;- length(j$response$docs)
  for (i in 1:nmod) {
      #select one list at a time
      j1 &lt;- j$response$docs[[i]]
      tmp &lt;- data.frame(variable=j1$variable,
                          variable_long_name=j1$variable_long_name,
                          rcm_name=j1$rcm_name,
                          driving_model=j1$driving_model,
                          cf_standard_name=j1$cf_standard_name
                          )
      #join them
      if (i==1) {
          d &lt;- tmp
      } else {
          d &lt;- rbind(d, tmp)
      }
  }
  </code></pre>
  
  <p>However, I'd like to know if there is a more elegant and efficient way, maybe using <code>tidyr</code>, <code>dplyr</code> or <code>purrr</code>, which also would allow me to select all ¨columns¨, instead of just the few selected there.</p>