Let me ask in another way, if it is possible to include other websites’ index (not WordPress) using some api in Solr or Elasticsearch, and make them connect to WPSolr so as to combine all the results in WordPress?
Upon your reply, all we need to do for making it searchable in files’ contents with extensions like pdf, ppt, docx… is uploading the files via media in wordpress. Remaining process is controlled by WPSolr no matter what search engine we choose.
About activating the plugin, could you provide us the web addresses that needs to access when activating the plugin?
