Using a renderIntent lib function instead of this identifier

A 'this' identifier is quite useless with compressed JavaScript,
and in fact it turned out to fail in advanced mode when trying
to access a feature's renderIntent property with it. The added
renderIntent lib function as a Call expression does the job
well.

examples/select-features.js

@@ -25,7 +25,7 @@ var vector = new ol.layer.Vector({
   style: new ol.style.Style({
     rules: [
       new ol.style.Rule({
-        filter: 'this.renderIntent == "selected"',
+        filter: 'renderIntent("selected")',
         symbolizers: [
           new ol.style.Fill({
             color: '#ffffff',

src/ol/expr/expression.js

@@ -99,6 +99,7 @@ ol.expr.functions = {
   EXTENT: 'extent',
   FID: 'fid',
   GEOMETRY_TYPE: 'geometryType',
+  RENDER_INTENT: 'renderIntent',
   INTERSECTS: 'intersects',
   CONTAINS: 'contains',
   DWITHIN: 'dwithin',
@@ -252,6 +253,17 @@ ol.expr.lib[ol.expr.functions.GEOMETRY_TYPE] = function(type) {
 };
 
 
+/**
+ * Determine if a feature's renderIntent matches the given one.
+ * @param {string} renderIntent Render intent.
+ * @return {boolean} The feature's renderIntent matches the given one.
+ * @this {ol.Feature}
+ */
+ol.expr.lib[ol.expr.functions.RENDER_INTENT] = function(renderIntent) {
+  return this.renderIntent == renderIntent;
+};
+
+
 ol.expr.lib[ol.expr.functions.INTERSECTS] = function(geom, opt_projection,
     opt_attribute) {
   throw new Error('Spatial function not implemented: ' +

src/ol/expr/expressions.js

@@ -10,7 +10,6 @@ goog.provide('ol.expr.Math');
 goog.provide('ol.expr.MathOp');
 goog.provide('ol.expr.Member');
 goog.provide('ol.expr.Not');
-goog.provide('ol.expr.ThisIdentifier');
 
 
 
@@ -625,24 +624,3 @@ ol.expr.Not.prototype.evaluate = function(opt_scope, opt_fns, opt_this) {
 ol.expr.Not.prototype.getArgument = function() {
   return this.argument_;
 };
-
-
-
-/**
- * An identifier for the 'this' keyword.
- *
- * @constructor
- * @extends {ol.expr.Expression}
- */
-ol.expr.ThisIdentifier = function() {};
-goog.inherits(ol.expr.ThisIdentifier, ol.expr.Expression);
-goog.addSingletonGetter(ol.expr.ThisIdentifier);
-
-
-/**
- * @inheritDoc
- */
-ol.expr.ThisIdentifier.prototype.evaluate =
-    function(opt_scope, opt_fns, opt_this) {
-  return opt_this;
-};

src/ol/expr/lexer.js

@@ -516,8 +516,7 @@ ol.expr.Lexer.prototype.scanIdentifier_ = function(code) {
   if (id.length === 1) {
     type = ol.expr.TokenType.IDENTIFIER;
   } else if (this.isKeyword_(id)) {
-    type = (id === 'this') ?
-        ol.expr.TokenType.THIS_IDENTIFIER : ol.expr.TokenType.KEYWORD;
+    type = ol.expr.TokenType.KEYWORD;
   } else if (id === 'null') {
     type = ol.expr.TokenType.NULL_LITERAL;
   } else if (id === 'true' || id === 'false') {

src/ol/expr/parser.js

@@ -30,7 +30,6 @@ goog.require('ol.expr.Math');
 goog.require('ol.expr.MathOp');
 goog.require('ol.expr.Member');
 goog.require('ol.expr.Not');
-goog.require('ol.expr.ThisIdentifier');
 goog.require('ol.expr.Token');
 goog.require('ol.expr.TokenType');
 goog.require('ol.expr.UnexpectedToken');
@@ -199,16 +198,6 @@ ol.expr.Parser.prototype.createMemberExpression_ = function(object,
 };
 
 
-/**
- * Create a 'this' identifier.
- * @return {ol.expr.ThisIdentifier} The 'this' identifier.
- * @private
- */
-ol.expr.Parser.prototype.createThisIdentifier_ = function() {
-  return ol.expr.ThisIdentifier.getInstance();
-};
-
-
 /**
  * Create a unary expression.  The only true unary operator supported here is
  * "!".  For +/-, we apply the operator to literal expressions and return
@@ -445,8 +434,6 @@ ol.expr.Parser.prototype.parsePrimaryExpression_ = function(lexer) {
     expr = this.createLiteral_(token.value === 'true');
   } else if (type === ol.expr.TokenType.NULL_LITERAL) {
     expr = this.createLiteral_(null);
-  } else if (type === ol.expr.TokenType.THIS_IDENTIFIER) {
-    expr = this.createThisIdentifier_();
   } else {
     throw new ol.expr.UnexpectedToken(token);
   }

test/spec/ol/expr/expression.test.js

@@ -92,12 +92,6 @@ describe('ol.expr.parse()', function() {
       expect(expr.evaluate(scope)).to.be(42);
     });
 
-    it('parses member expressions in the \'this\' scope', function() {
-      var expr = ol.expr.parse('this.foo');
-      var thisScope = {foo: 'bar'};
-      expect(expr.evaluate(undefined, undefined, thisScope)).to.be('bar');
-    });
-
     it('consumes whitespace as expected', function() {
       var expr = ol.expr.parse(' foo . bar . baz ');
       expect(expr).to.be.a(ol.expr.Member);
@@ -878,6 +872,24 @@ describe('ol.expr.lib', function() {
 
   });
 
+  describe('renderIntent()', function() {
+
+    var feature = new ol.Feature();
+    feature.renderIntent = 'foo';
+
+    var isFoo = parse('renderIntent("foo")');
+    var isBar = parse('renderIntent("bar")');
+
+    it('True when renderIntent matches', function() {
+      expect(evaluate(isFoo, feature), true);
+    });
+
+    it('False when renderIntent does not match', function() {
+      expect(evaluate(isBar, feature), false);
+    });
+
+  });
+
 });
 
 describe('ol.expr.register()', function() {

test/spec/ol/expr/expressions.test.js

@@ -624,25 +624,6 @@ describe('ol.expr.Not', function() {
 });
 
 
-describe('ol.expr.ThisIdentifier', function() {
-
-  describe('#getInstance()', function() {
-    it('has a getInstance method to return the singleton', function() {
-      expect(ol.expr.ThisIdentifier.getInstance())
-          .to.be.a(ol.expr.ThisIdentifier);
-    });
-  });
-
-  describe('#evaluate()', function() {
-    it('evaluates to the passed scope', function() {
-      expect(ol.expr.ThisIdentifier.getInstance()
-          .evaluate(undefined, undefined, 'foo')).to.be('foo');
-    });
-  });
-
-});
-
-
 goog.require('ol.expr.Call');
 goog.require('ol.expr.Comparison');
 goog.require('ol.expr.ComparisonOp');
@@ -655,4 +636,3 @@ goog.require('ol.expr.Math');
 goog.require('ol.expr.MathOp');
 goog.require('ol.expr.Member');
 goog.require('ol.expr.Not');
-goog.require('ol.expr.ThisIdentifier');