Implement round filter

lawrencec · Jun 9, 2014 · 667ad0c · 667ad0c
1 parent bcc3632
commit 667ad0c
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Showing 5 changed files with 186 additions and 3 deletions.
diff --git a/src/twig.filters.js b/src/twig.filters.js
@@ -507,6 +507,28 @@ var Twig = (function (Twig) {
         raw: function(value) {
             //Raw filter shim
             return value;
+        },
+        round: function(value, params) {
+            params = params || [];
+
+            var precision = params.length > 0 ? params[0] : 0,
+                method = params.length > 1 ? params[1] : "common";
+
+            value = parseFloat(value);
+
+            if(precision && !Twig.lib.is("Number", precision)) {
+                throw new Twig.Error("round filter expects precision to be a number");
+            }
+
+            if (method === "common") {
+                return Twig.lib.round(value, precision);
+            }
+
+            if(!Twig.lib.is("Function", Math[method])) {
+                throw new Twig.Error("round filter expects method to be 'floor', 'ceil', or 'common'");
+            }
+
+            return Math[method](value * Math.pow(10, precision)) / Math.pow(10, precision);
         }
     };
 

diff --git a/src/twig.lib.js b/src/twig.lib.js
@@ -612,6 +612,60 @@ var Twig = (function(Twig) {
         return string.split(search).join(replace);
     };
 
+    Twig.lib.round = function round(value, precision, mode) {
+        //  discuss at: http://phpjs.org/functions/round/
+        // original by: Philip Peterson
+        //  revised by: Onno Marsman
+        //  revised by: T.Wild
+        //  revised by: Rafał Kukawski (http://blog.kukawski.pl/)
+        //    input by: Greenseed
+        //    input by: meo
+        //    input by: William
+        //    input by: Josep Sanz (http://www.ws3.es/)
+        // bugfixed by: Brett Zamir (http://brett-zamir.me)
+        //        note: Great work. Ideas for improvement:
+        //        note: - code more compliant with developer guidelines
+        //        note: - for implementing PHP constant arguments look at
+        //        note: the pathinfo() function, it offers the greatest
+        //        note: flexibility & compatibility possible
+        //   example 1: round(1241757, -3);
+        //   returns 1: 1242000
+        //   example 2: round(3.6);
+        //   returns 2: 4
+        //   example 3: round(2.835, 2);
+        //   returns 3: 2.84
+        //   example 4: round(1.1749999999999, 2);
+        //   returns 4: 1.17
+        //   example 5: round(58551.799999999996, 2);
+        //   returns 5: 58551.8
+
+        var m, f, isHalf, sgn; // helper variables
+        precision |= 0; // making sure precision is integer
+        m = Math.pow(10, precision);
+        value *= m;
+        sgn = (value > 0) | -(value < 0); // sign of the number
+        isHalf = value % 1 === 0.5 * sgn;
+        f = Math.floor(value);
+
+        if (isHalf) {
+            switch (mode) {
+                case 'PHP_ROUND_HALF_DOWN':
+                    value = f + (sgn < 0); // rounds .5 toward zero
+                    break;
+                case 'PHP_ROUND_HALF_EVEN':
+                    value = f + (f % 2 * sgn); // rouds .5 towards the next even integer
+                    break;
+                case 'PHP_ROUND_HALF_ODD':
+                    value = f + !(f % 2); // rounds .5 towards the next odd integer
+                    break;
+                default:
+                    value = f + (sgn > 0); // rounds .5 away from zero
+            }
+        }
+
+        return (isHalf ? value : Math.round(value)) / m;
+    }
+
     return Twig;
 
 })(Twig || { });
diff --git a/test/test.filters.js b/test/test.filters.js
@@ -480,6 +480,37 @@ describe("Twig.js Filters ->", function() {
         });
     });
 
+    describe('round ->', function () {
+        it('should round up (common)', function () {
+            var test_template = twig({data: "{{ 2.7|round }}"});
+            test_template.render().should.equal("3");
+        });
+        it('should round down (common)', function () {
+            var test_template = twig({data: "{{ 2.1|round }}"});
+            test_template.render().should.equal("2");
+        });
+        it('should truncate input when input decimal places exceeds precision (floor)', function () {
+            var test_template = twig({data: "{{ 2.1234|round(3, 'floor') }}" });
+            test_template.render().should.equal("2.123");
+        });
+        it('should round up (ceil)', function () {
+            var test_template = twig({data: "{{ 2.1|round(0, 'ceil') }}" });
+            test_template.render().should.equal("3");
+        });
+        it('should truncate precision when a negative precision is passed (common)', function () {
+            var test_template = twig({data: "{{ 21.3|round(-1)}}" });
+            test_template.render().should.equal("20");
+        });
+        it('should round up and truncate precision when a negative precision is passed (ceil)', function () {
+            var test_template = twig({data: "{{ 21.3|round(-1, 'ceil')}}" });
+            test_template.render().should.equal("30");
+        });
+        it('should round down and truncate precision when a negative precision is passed (floor)', function () {
+            var test_template = twig({data: "{{ 21.3|round(-1, 'ceil')}}" });
+            test_template.render().should.equal("30");
+        });
+    });
+
     it("should chain", function() {
         var test_template = twig({data: '{{ ["a", "b", "c"]|keys|reverse }}' });
         test_template.render().should.equal("2,1,0");

diff --git a/twig.js b/twig.js
@@ -1706,6 +1706,60 @@ var Twig = (function(Twig) {
         return string.split(search).join(replace);
     };
 
+    Twig.lib.round = function round(value, precision, mode) {
+        //  discuss at: http://phpjs.org/functions/round/
+        // original by: Philip Peterson
+        //  revised by: Onno Marsman
+        //  revised by: T.Wild
+        //  revised by: Rafał Kukawski (http://blog.kukawski.pl/)
+        //    input by: Greenseed
+        //    input by: meo
+        //    input by: William
+        //    input by: Josep Sanz (http://www.ws3.es/)
+        // bugfixed by: Brett Zamir (http://brett-zamir.me)
+        //        note: Great work. Ideas for improvement:
+        //        note: - code more compliant with developer guidelines
+        //        note: - for implementing PHP constant arguments look at
+        //        note: the pathinfo() function, it offers the greatest
+        //        note: flexibility & compatibility possible
+        //   example 1: round(1241757, -3);
+        //   returns 1: 1242000
+        //   example 2: round(3.6);
+        //   returns 2: 4
+        //   example 3: round(2.835, 2);
+        //   returns 3: 2.84
+        //   example 4: round(1.1749999999999, 2);
+        //   returns 4: 1.17
+        //   example 5: round(58551.799999999996, 2);
+        //   returns 5: 58551.8
+
+        var m, f, isHalf, sgn; // helper variables
+        precision |= 0; // making sure precision is integer
+        m = Math.pow(10, precision);
+        value *= m;
+        sgn = (value > 0) | -(value < 0); // sign of the number
+        isHalf = value % 1 === 0.5 * sgn;
+        f = Math.floor(value);
+
+        if (isHalf) {
+            switch (mode) {
+                case 'PHP_ROUND_HALF_DOWN':
+                    value = f + (sgn < 0); // rounds .5 toward zero
+                    break;
+                case 'PHP_ROUND_HALF_EVEN':
+                    value = f + (f % 2 * sgn); // rouds .5 towards the next even integer
+                    break;
+                case 'PHP_ROUND_HALF_ODD':
+                    value = f + !(f % 2); // rounds .5 towards the next odd integer
+                    break;
+                default:
+                    value = f + (sgn > 0); // rounds .5 away from zero
+            }
+        }
+
+        return (isHalf ? value : Math.round(value)) / m;
+    };
+
     return Twig;
 
 })(Twig || { });
@@ -4521,6 +4575,28 @@ var Twig = (function (Twig) {
         raw: function(value) {
             //Raw filter shim
             return value;
+        },
+        round: function(value, params) {
+            params = params || [];
+
+            var precision = params.length > 0 ? params[0] : 0,
+                method = params.length > 1 ? params[1] : "common";
+
+            value = parseFloat(value);
+
+            if(precision && !Twig.lib.is("Number", precision)) {
+                throw new Twig.Error("round filter expects precision to be a number");
+            }
+
+            if (method === "common") {
+                return Twig.lib.round(value, precision);
+            }
+
+            if(!Twig.lib.is("Function", Math[method])) {
+                throw new Twig.Error("round filter expects method to be 'floor', 'ceil', or 'common'");
+            }
+
+            return Math[method](value * Math.pow(10, precision)) / Math.pow(10, precision);
         }
     };
 

diff --git a/twig.min.js b/twig.min.js