diff --git a/src/operations/category-chart.component.ts b/src/operations/category-chart.component.ts
index 57fb11b..079fa39 100644
--- a/src/operations/category-chart.component.ts
+++ b/src/operations/category-chart.component.ts
@@ -1,24 +1,5 @@
-// vim: set tw=80 ts=4 sw=4 sts=4:
-/*
-    This file is part of Accountant.
+// vim: set tw=80 ts=2 sw=2 sts=2 :
 
-    Accountant is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    Accountant is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU Affero General Public License for more details.
-
-    You should have received a copy of the GNU Affero General Public License
-    along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
- */
-/* jshint node: true */
-'use strict';
-
-import * as moment from 'moment';
 import * as c3 from 'c3';
 
 import {
@@ -27,101 +8,103 @@ import {
   OnInit, OnChanges
 } from '@angular/core';
 
+import { Logger } from '@nsalaun/ng-logger';
+
 import { Account } from '../accounts/account';
 import { CategoryService } from './category.service';
 
 @Component({
-    selector: 'category-chart',
-    template: '<div></div>'
+  selector: 'category-chart',
+  template: '<div></div>'
 })
 export class CategoryChartComponent implements OnInit, OnChanges {
-    @Input() minDate: Date;
-    @Input() maxDate: Date;
-    @Input() account: Account;
+  @Input() minDate: Date;
+  @Input() maxDate: Date;
+  @Input() account: Account;
 
-    chart: c3.ChartAPI;
+  chart: c3.ChartAPI;
 
-    constructor(
-        private elementRef: ElementRef,
-        private categoryService: CategoryService,
-    ) {}
+  constructor(
+    private elementRef: ElementRef,
+    private categoryService: CategoryService,
+    private logger: Logger,
+  ) {}
 
-            loadData(account: Account) {
-                this.categoryService.query(
-                    account.id,
-                    this.minDate,
-                    this.maxDate
-                ).subscribe((results) => {
-                    var expenses=[],
-                        revenues=[],
-                        colors={},
-                        names={};
+  loadData(account: Account) {
+    this.categoryService.query(
+      account.id,
+      this.minDate,
+      this.maxDate
+    ).subscribe((results) => {
+      var expenses=[],
+        revenues=[],
+        colors={},
+        names={};
 
-                    var revenuesColor = 'green',
-                        expensesColor = 'orange';
+      var revenuesColor = 'green',
+        expensesColor = 'orange';
 
-                    for(let result of results) {
+      for(let result of results) {
+        if(result.revenues > 0) {
+          var revenuesName = 'revenues-' + result.category;
 
-                        if(result.revenues > 0) {
-                            var revenuesName = 'revenues-' + result.category;
+          revenues.push([revenuesName, result.revenues]);
+          names[revenuesName] = result.category;
+          colors[revenuesName] = revenuesColor;
+        }
 
-                            revenues.push([revenuesName, result.revenues]);
-                            names[revenuesName] = result.category;
-                            colors[revenuesName] = revenuesColor;
-                        }
+        if(result.expenses < 0) {
+          var expensesName = 'expenses-' + result.category;
 
-                        if(result.expenses < 0) {
-                            var expensesName = 'expenses-' + result.category;
+          expenses.splice(0, 0, [expensesName, -result.expenses]);
+          names[expensesName] = result.category;
+          colors[expensesName] = expensesColor;
+        }
+      };
 
-                            expenses.splice(0, 0, [expensesName, -result.expenses]);
-                            names[expensesName] = result.category;
-                            colors[expensesName] = expensesColor;
-                        }
-                    };
+      this.chart.unload();
 
-                    this.chart.unload();
+      this.chart.load({
+        columns: revenues.concat(expenses),
+        names: names,
+        colors: colors
+      });
+    });
+  };
 
-                    this.chart.load({
-                        columns: revenues.concat(expenses),
-                        names: names,
-                        colors: colors
-                    });
-                });
-            };
+  ngOnInit() {
+    this.chart = c3.generate({
+      bindto: this.elementRef.nativeElement.children[0],
+      data: {
+        columns: [],
+        type: 'donut',
+        order: null,
+      },
+      tooltip: {
+        format: {
+          value: function(value, ratio, id, index) {
+            return value + '€';
+          }
+        }
+      },
+      donut: {
+        label: {
+          format: function(value) {
+            return value + '€';
+          }
+        }
+      },
+      legend: {
+        show: false
+      }
+    });
+  };
 
-            ngOnInit() {
-                this.chart = c3.generate({
-                    bindto: this.elementRef.nativeElement.children[0],
-                    data: {
-                        columns: [],
-                        type: 'donut',
-                        order: null,
-                    },
-                    tooltip: {
-                        format: {
-                            value: function(value, ratio, id, index) {
-                                return value + '€';
-                            }
-                        }
-                    },
-                    donut: {
-                        label: {
-                            format: function(value) {
-                                return value + '€';
-                            }
-                        }
-                    },
-                    legend: {
-                        show: false
-                    }
-                });
-            };
-
-            ngOnChanges(changes) {
-                if('account' in changes && changes.account.currentValue) {
-                    this.loadData(changes.account.currentValue);
-                } else if (this.account) {
-                    this.loadData(this.account);
-                }
-            };
+  ngOnChanges(changes) {
+    if('account' in changes && changes.account.currentValue) {
+      this.loadData(changes.account.currentValue);
+    } else if (this.account) {
+      this.loadData(this.account);
+    }
+  };
 }