title: Loop pages and crawler excel file path using rvest
body: <p>For the entries from <a href="http://www.csrc.gov.cn/csrc/c100121/common_list.shtml" rel="nofollow noreferrer">this link</a>, I need to click each entry, then crawler url of excel file's path in the left bottom part of page:</p>
  <p><a href="https://i.stack.imgur.com/r56kd.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/r56kd.png" alt="enter image description here" /></a></p>
  <p>How could I achieve that using web scrapy packages in R such as <code>rvest</code>, etc.? Sincere thanks at advance.</p>
  <pre><code>library(rvest)
  
  # Start by reading a HTML page with read_html():
  common_list &lt;- read_html(&quot;http://www.csrc.gov.cn/csrc/c100121/common_list.shtml&quot;)
  common_list %&gt;%
    # extract paragraphs
    rvest::html_nodes(&quot;a&quot;) %&gt;%
    # extract text
    rvest::html_text() -&gt; webtxt
  # inspect
  head(webtxt)
  </code></pre>
  <p>First, my question is how could I correctly set <code>html_nodes</code> to get url of each web page?</p>
  <p><a href="https://i.stack.imgur.com/jdJkH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jdJkH.png" alt="enter image description here" /></a></p>
  <p><strong>Update:</strong></p>
  <pre><code>&gt; driver
  $client
  [1] &quot;No sessionInfo. Client browser is mostly likely not opened.&quot;
  
  $server
  PROCESS 'file105483d2b3a.bat', running, pid 37512.
  &gt; remDr
  $remoteServerAddr
  [1] &quot;localhost&quot;
  
  $port
  [1] 4567
  
  $browserName
  [1] &quot;chrome&quot;
  
  $version
  [1] &quot;&quot;
  
  $platform
  [1] &quot;ANY&quot;
  
  $javascript
  [1] TRUE
  
  $nativeEvents
  [1] TRUE
  
  $extraCapabilities
  list()
  </code></pre>
  <p>When I run <code>remDr$navigate(url)</code>:</p>
  <pre><code>Error in checkError(res) : 
    Undefined error in httr call. httr output: length(url) == 1 is not TRUE
  </code></pre>