User:Thesevenseas/pagediff.js

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if (typeof (pagediff) == 'undefined') { // Guard against double inclusions

 var pagediff = {
  page1: "",
  page2: "",

  callback: function(jsonobj) {
    
    if( jsonobj && jsonobj.query ) {
     var revid1 = 0;
     var revid2 = 0;
     for (var page in jsonobj.query.pages) {
       var p = jsonobj.query.pages[page];
       if( !revid1 ) revid1 = p.revisions[0].revid;
       else revid2 = p.revisions[0].revid;
     }
    }
    document.location.href = wgScript + "?title=" + encodeURIComponent( "User:Thesevenseas/Pagediff"  )+ "&oldid=" + revid1 + "&diff=" + revid2;
  },

  setup: function() {
    pagediff.page1 = getURLParamValue( "oldpage" ).replace( "+", "_" );
    pagediff.page2 = getURLParamValue( "newpage" ).replace( "+", "_" );

    mw.loader.load( wgScriptPath + "/api.php?action=query&format=json&prop=revisions&rvprop=ids&titles=" + encodeURIComponent(pagediff.page1) + "|" + encodeURIComponent(pagediff.page2) + "&callback=pagediff.callback"  );
  }

 }
}

pagediff.setup();