Allow getMetersPerUnit to work without units identifier (see #814)

externs/proj4js.js

@@ -76,6 +76,12 @@ Proj4js.Proj.prototype.units;
 Proj4js.Proj.prototype.srsCode;
 
 
+/**
+ * @type {number}
+ */
+Proj4js.Proj.prototype.to_meter;
+
+
 /**
  * @nosideeffects
  * @param {Proj4js.Proj} source

src/ol/proj/proj.js

@@ -143,7 +143,15 @@ ol.Projection.prototype.getUnits = function() {
  * @return {number} Meters.
  */
 ol.Projection.prototype.getMetersPerUnit = function() {
-  return ol.METERS_PER_UNIT[this.units_];
+  var metersPerUnit;
+  if (!goog.isNull(this.units_)) {
+    metersPerUnit = ol.METERS_PER_UNIT[this.units_];
+  } else {
+    if (this instanceof ol.Proj4jsProjection_) {
+      metersPerUnit = this.getProj4jsProj().to_meter;
+    }
+  }
+  return metersPerUnit;
 };
 
 

test/spec/ol/proj/proj.test.js

@@ -313,11 +313,31 @@ describe('ol.proj', function() {
 
   describe('ol.Projection.prototype.getMetersPerUnit()', function() {
 
+    beforeEach(function() {
+      Proj4js.defs['EPSG:26782'] =
+          '+proj=lcc +lat_1=29.3 +lat_2=30.7 +lat_0=28.66666666666667 ' +
+          '+lon_0=-91.33333333333333 +x_0=609601.2192024384 +y_0=0 ' +
+          '+ellps=clrk66 +datum=NAD27 +to_meter=0.3048006096012192 +no_defs';
+      ol.proj.configureProj4jsProjection({
+        code: 'EPSG:26782'
+      });
+    });
+
+    afterEach(function() {
+      ol.proj.proj4jsProjections_ = {};
+      delete Proj4js.defs['EPSG:26782'];
+    });
+
     it('returns value in meters', function() {
       var epsg4326 = ol.proj.get('EPSG:4326');
       expect(epsg4326.getMetersPerUnit()).to.eql(111194.87428468118);
     });
 
+    it('works for proj4js projections without units', function() {
+      var epsg26782 = ol.proj.get('EPSG:26782');
+      expect(epsg26782.getMetersPerUnit()).to.eql(0.3048006096012192);
+    });
+
   });
 
   describe('ol.proj.configureProj4jsProjection()', function() {