Implemented batch filter

twigjs · Jun 8, 2014 · 19fe85e · 19fe85e
1 parent bcc3632
commit 19fe85e
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Showing 3 changed files with 72 additions and 0 deletions.
diff --git a/src/twig.filters.js b/src/twig.filters.js
@@ -507,6 +507,38 @@ var Twig = (function (Twig) {
         raw: function(value) {
             //Raw filter shim
             return value;
+        },
+        batch: function(items, params) {
+            var size = params.shift(),
+                fill = params.shift(),
+                result,
+                last,
+                missing;
+
+            if (!Twig.lib.is("Array", items)) {
+                throw new Twig.Error("batch filter expects items to be an array");
+            }
+
+            if (!Twig.lib.is("Number", size)) {
+                throw new Twig.Error("batch filter expects size to be a number");
+            }
+
+            size = Math.ceil(size);
+
+            result = Twig.lib.chunkArray(items, size);
+
+            if (fill && items.length % size != 0) {
+                last = result.pop();
+                missing = size - last.length;
+
+                while (missing--) {
+                    last.push(fill);
+                }
+
+                result.push(last);
+            }
+
+            return result;
         }
     };
 

diff --git a/src/twig.lib.js b/src/twig.lib.js
@@ -612,6 +612,23 @@ var Twig = (function(Twig) {
         return string.split(search).join(replace);
     };
 
+    // chunk an array (arr) into arrays of (size) items, returns an array of arrays, or an empty array on invalid input
+    Twig.lib.chunkArray = function (arr, size) {
+        var returnVal = [],
+            x = 0,
+            len = arr.length;
+
+        if (size < 1 || !Twig.lib.is("Array", arr)) {
+            return [];
+        }
+
+        while (x < len) {
+            returnVal.push(arr.slice(x, x += size));
+        }
+
+        return returnVal;
+    };
+
     return Twig;
 
 })(Twig || { });
diff --git a/test/test.filters.js b/test/test.filters.js
@@ -465,6 +465,29 @@ describe("Twig.js Filters ->", function() {
         });
     });
 
+    describe('batch ->', function () {
+        it('should work with arrays that require filling (with fill specified)', function () {
+            var test_template = twig({data: "{{ ['a', 'b', 'c', 'd', 'e', 'f', 'g']|batch(3, 'x') }}"});
+            test_template.render().should.equal("a,b,c,d,e,f,g,x,x");
+        });
+        it('should work with arrays that require filling (without fill specified)', function () {
+            var test_template = twig({data: "{{ ['a', 'b', 'c', 'd', 'e', 'f', 'g']|batch(3) }}"});
+            test_template.render().should.equal("a,b,c,d,e,f,g");
+        });
+        it('should work with arrays that do not require filling (with fill specified)', function () {
+            var test_template = twig({data: "{{ ['a', 'b', 'c', 'd', 'e', 'f']|batch(3, 'x') }}"});
+            test_template.render().should.equal("a,b,c,d,e,f");
+        });
+        it('should work with arrays that do not require filling (without fill specified)', function () {
+            var test_template = twig({data: "{{ ['a', 'b', 'c', 'd', 'e', 'f']|batch(3) }}"});
+            test_template.render().should.equal("a,b,c,d,e,f");
+        });
+        it('should return an empty result for an empty array', function () {
+            var test_template = twig({data: "{{ []|batch(3, 'x') }}"});
+            test_template.render().should.equal("");
+        });
+    });
+
     describe('last ->', function () {
         it('should return last character in string', function () {
             var test_template = twig({data: "{{ 'abcd'|last }}"});