Difference between revisions of "Umlaut partial html API javascript helper"

Revision as of 19:56, 2 October 2008

If you want to include Umlaut-generated HTML directly on a third party page via javascript, there is a javascript helper script to make that very easy. This helper uses the Umlaut partial HTML api, but does everything for you. The helper will update your divs, and keep polling Umlaut for new results, continuing to re-update your divs until Umlaut is finished. How often it polls is configured by application config 'poll_wait_seconds', which defaults to 4.

Overview

You need to specify your Umlaut base URL in a global javascript variable called umlaut_base. This is not your link resolver base url which for Umlaut ends in /resolve, but the actual Umlaut application base URL, which should be the same, without the /resolve. At JHU, it's "http://findit.library.jhu.edu".

You also need to put a URL-formatted (KEV) OpenURL context object in a global js variable called umlaut_openurl_kev_co.

You then specify mappings from Umlaut html sections to HTML divs on your page in global js variable called umlaut_section_map containing a hash. Umlaut html sections are configured in Umlaut in the "partial_html_map" configuration param, which by default is set to the "bg_update_map" config params :divs key. To see the sections in a default Umlaut installation, see: environment.rb in svn, look for bg_update_map. The :divs key of the hash there is an array of hashes, each individual hash has a :div_id key that corresponds to the html_sections id in this api response. For Umlaut developers, the :partial key tells you what Rails partial is used to generate this section.

You can also optionally use some javascript callbacks to perform behavior after or during loading. In the following example, we'll demo using a javascript callback to only show a div for search_inside functionality if there are search_inside tools provided.

The umlaut_embed.js script will check if the javascript Prototype library is loaded into the host page, and load it if not. Among other things, this means you can use Prototype in your callbacks.

The html loaded will sometimes include a "spinner" with a message "loading more", if the content is not yet loaded.

An example is best:

Example

  <H1>Here is an article page. </h1>

  <p>We're looking up Cytoplasmic Control of nuclear behavior by Masui. Of course normally this
     would be dynamically generated, not in static html like this.<p>

  <!-- umlaut full text will be loaded here. You might want to include some initial content
       here for browsers without javascript. For browsers with javascript, this will be overwritten.-->
  <div id="my_fulltext">
     <a href="http://umlaut.university.edu/resolve?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft_id=info:doi/10.1002/jez.1401770202&rfr_id=info:sid/university.edu:myapplication&rft.genre=article&rft.jtitle=J.%20Exp.%20Zool&rft.date=1971&rft.atitle=Cytoplasmic%20control%20of%20nuclear%20behavior&rft.aulast=Masui">
        Link to umlaut
      </a>
  </div>

  <!-- we hide this div to start out with, our js callback later 
       will show it there is full text. But we avoid a "spinner" showing up
       here before everything is fully loaded.  -->
  <div id="my_search_inside" style="display:none;"></div>

  <div id="my_cover"></div>

  <div id="my_see_also"</div>

  <div id="my_excerpts"></div>

  
  <!-- now the javascript to actually load content in those divs -->

  <script type="text/javascript">
    // You have to generate an OpenURL context object somehow, and set it in a js global var. 
    // Normally this would be generated dynamically, not static HTML like this, of course.
    // You may want to include a rfr_id to identify your application as a source, demo below. 

    umlaut_openurl_kev_co = 'url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft_id=info:doi/10.1002/jez.1401770202&rfr_id=info:sid/university.edu:myapplication&rft.genre=article&rft.jtitle=J.%20Exp.%20Zool&rft.date=1971&rft.atitle=Cytoplasmic%20control%20of%20nuclear%20behavior&rft.aulast=Masui';

    // set global js var to tell script where to find umlaut
    umlaut_base = 'http://umlaut.university.edu';

    // Map of umlaut section id to: div id we want to put it on the page
    // Note the js call back for search_inside_wrapper, to only show the
    // div on our page if there are elements. Js callback function gets one
    // argument, which will be number of Umlaut responses in the section. 
    // Note also that we can use Prototype in the callback. 

    umlaut_section_map = {
      'fulltext_wrapper': 'my_fulltext',
      'highlighted_links': 'my_see_also',
      'excerpts_wrapper': 'my_excerpts',
      'cover_image': 'my_cover',
      'search_inside_wrapper': {'host_div_id': 'my_search_inside', 
                                'after_update':
                                  function(count) {
                                    if ( count > 0) {
                                        $('my_search_inside').show();
                                    }
                                  }
                              }
      };
    </script>

    <!-- now actually load the umlaut js helper, which will do the magic for you -->
    <script type="text/javascript" src="http://umlaut.university.edu/javascripts/embed/umlaut-embed.js"></script>