Disqus embed code for a single page javascript app, with optional SSO.

disqus.js

// Enable or reset Disqus for this page as required, with optional SSO.
// There must be a div with id "disqus_thread" when called.
// 
// config is required and should have the format:
//
//  { 
//    shortname:  "..",
//    title:      "..",
//    identifier: "..",
//    url:        ".."
//  }
//
//  config.shortname *should not* change between invocations.
//
// sso_config is optional and if present should have the format:
//
//  { 
//    api_key:   "..", 
//    message:   "..", 
//    sig:       "..", 
//    timestamp: 2487239473
//  }
function enableDisqus(config, sso_config) { 
  if (enableDisqus.loaded) {
    DISQUS.reset({
      reload: true,
      config: function () {  
        this.page.identifier = config.identifier;
        this.page.url        = config.url;
        this.page.title      = config.title;
      }
    });
  } else {
    var body = "var disqus_shortname  = \"" + config.shortname  + "\";\n" + 
               "var disqus_title      = \"" + config.title      + "\";\n" + 
               "var disqus_identifier = \"" + config.identifier + "\";\n" +
               "var disqus_url        = \"" + config.url        + "\";\n";
    if (config.developer) {
      body +=  "var disqus_developer  = 1;\n"
    }
    appendScriptTagWithBody(body);
 
    (function() {
      var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
      dsq.src = 'http://' + disqus_shortname + '.disqus.com/embed.js';
      (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
    })();
 
    if (sso_config) {
      var remote_auth_s3 = sso_config.message + " " + sso_config.sig + " " + sso_config.timestamp;
      var body = "var disqus_config = function() {\n" + 
                 "  this.page.remote_auth_s3 = \"" + remote_auth_s3     + "\";\n" + 
                 "  this.page.api_key        = \"" + sso_config.api_key + "\";\n" + 
                 "};\n"
      appendScriptTagWithBody(body)
    }
 
    enableDisqus.loaded = true;
  }
}
 
function appendScriptTagWithBody(body) {
  var dso   = document.createElement("script");
  dso.type  = "text/javascript";
  dso.async = true;
  dso.text  = body;
  console.log(body);
  document.getElementsByTagName('body')[0].appendChild(dso);
}