Add popFromColumn

spec/api.load-spec.js

@@ -123,26 +123,75 @@ describe('c3 api load', function () {
             chart.loadColumns([['data1', 0, 100, 200]]);
             chart.appendToColumn(['data1', 300, 400, 500]);
 
-            var data = chart.getDataById('data1');
-
-            for(var i = 0; i < data.length; i++){
-                expect(data[i].value).toBe(i*100);
-            }
+            setTimeout(function(){
+                var data = chart.getDataById('data1');
+                for(var i = 0; i < data.length; i++){
+                    expect(data[i].value).toBe(i*100);
+                }
 
-            done();
+                done();
+            }, 500);
         });
 
         it('should append values to non-existing column', function(done){
             chart.appendToColumn(['data5', 0, 100, 200, 300]);
 
-            var data = chart.getDataById('data5');
+            setTimeout(function(){
+                var data = chart.getDataById('data5');
+                for(var i = 0; i < data.length; i++){
+                    expect(data[i].value).toBe(i*100);
+                }
+
+                done();
+            }, 500);
+        });
+    });
+
+    describe("popFromColumn", function(){
+        it("should pop values from column", function(done){
+            chart.loadColumns([['data1', 0, 100, 200, 300]]);
+            chart.loadColumns([['data2', 0, -100, -200, -300]]);
+
+            chart.popFromColumn('data1', 1);
+            chart.popFromColumn('data2', 3);
+
+            setTimeout(function(){
+                var data1 = chart.getDataById('data1');
+                var data2 = chart.getDataById('data2');
+
+                expect(data1.length).toBe(3);
+                expect(data2.length).toBe(1);
 
-            for(var i = 0; i < data.length; i++){
-                expect(data[i].value).toBe(i*100);
-            }
+                for(var i = 0; i < data1.length; i++){
+                    expect(data1[i].value).toBe(i*100);
+                }
+                for(var i = 0; i < data2.length; i++){
+                    expect(data2[i].value).toBe(-i*100)
+                }
+
+                done();
+            }, 500);
+        });
 
+        it("should throw when non-existing sequence given", function(done){
+            expect(function(){
+                chart.popFromColumn('data2015', 2);
+            }).toThrow();
             done();
         });
+
+        it("shouldn't throw when popping more values than there is", function(done){
+            chart.loadColumns([['data1', 10, 20]]);
+
+            chart.popFromColumn('data1', 3);
+            expect(chart.getDataById('data1').length).toBe(0);
+
+            chart.popFromColumn('data1', 2);
+            expect(chart.getDataById('data1').length).toBe(0);
+
+            done();
+        });
+
     });
 
 });

src/api.load.js

@@ -69,6 +69,21 @@ c3_chart_fn.appendToColumn = function(col) {
     $$.api.loadColumns([col]);
 };
 
+c3_chart_fn.popFromColumn = function(id, amount){
+    var $$ = this.internal;
+    var columns = $$.api.getDataById(id);
+
+    if(isUndefined(columns)){
+        throw new Error("Popping values from non-existing sequence");
+    }
+
+    for(var i = 0; i < amount; i++){
+        columns.pop();
+    }
+
+    $$.api.loadColumns(columns);
+};
+
 c3_chart_fn.loadColumns = function(cols){
     var $$ = this.internal;
     $$.api.load({