WMS without client projection example

Example of two WMS layers using the projection EPSG:21781, which is unknown to the client.

As long as no coordinate transformations are required, OpenLayers 3 works fine with projections that are only configured with a code and units.

wms, projection
<!DOCTYPE html>
<html>
<head>
<title>WMS without client projection example</title>
<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://openlayers.org/en/v3.9.0/css/ol.css" type="text/css">
<script src="http://openlayers.org/en/v3.9.0/build/ol.js"></script>

</head>
<body>
<div class="container-fluid">

<div class="row-fluid">
  <div class="span12">
    <div id="map" class="map"></div>
  </div>
</div>

</div>
<script>
var layers = [
  new ol.layer.Tile({
    source: new ol.source.TileWMS({
      attributions: [new ol.Attribution({
        html: '&copy; ' +
            '<a href="http://www.geo.admin.ch/internet/geoportal/' +
            'en/home.html">' +
            'Pixelmap 1:1000000 / geo.admin.ch</a>'
      })],
      crossOrigin: 'anonymous',
      params: {
        'LAYERS': 'ch.swisstopo.pixelkarte-farbe-pk1000.noscale',
        'FORMAT': 'image/jpeg'
      },
      url: 'http://wms.geo.admin.ch/'
    })
  }),
  new ol.layer.Image({
    source: new ol.source.ImageWMS({
      attributions: [new ol.Attribution({
        html: '&copy; ' +
            '<a href="http://www.geo.admin.ch/internet/geoportal/' +
            'en/home.html">' +
            'National parks / geo.admin.ch</a>'
      })],
      crossOrigin: 'anonymous',
      params: {'LAYERS': 'ch.bafu.schutzgebiete-paerke_nationaler_bedeutung'},
      serverType: 'mapserver',
      url: 'http://wms.geo.admin.ch/'
    })
  })
];

// A minimal projection object is configured with only the SRS code and the map
// units. No client-side coordinate transforms are possible with such a
// projection object. Requesting tiles only needs the code together with a
// tile grid of Cartesian coordinates; it does not matter how those
// coordinates relate to latitude or longitude.
var projection = new ol.proj.Projection({
  code: 'EPSG:21781',
  units: 'm'
});

var map = new ol.Map({
  layers: layers,
  target: 'map',
  view: new ol.View({
    center: [660000, 190000],
    projection: projection,
    zoom: 9
  })
});

</script>
</body>
</html>