# Resource Header Customization (Open-Source Resource Calendar) | DayPilot Lite for JavaScript Demo

> The resource header displays an "edit" icon using an active area added in the onBeforeHeaderRender event handler. Read more about [column header active areas](https://doc.daypilot.org/calendar/column-header-active-areas/) [doc.daypilot.org].

## Links

- Canonical HTML: /demo/lite/calendar/resourceicons.html
- Source HTML folder: /demo/lite/calendar/
- Catalog root: /demo/lite/
- Catalog: /demo/lite/llms.txt

## Source

### Inline demo script 1

```javascript
const dp = new DayPilot.Calendar("dp", {
            startDate: "2022-06-24",
            viewType: "Resources",
            columns: [
                {name: "Room A", id: "A"},
                {name: "Room B", id: "B"},
                {name: "Room C", id: "C"},
                {name: "Room D", id: "D"},
            ],
            headerHeight: 40,
            onTimeRangeSelected: async (args) => {
                const modal = await DayPilot.Modal.prompt("New event name:", "Event");
                dp.clearSelection();
                if (modal.canceled) {
                    return;
                }
                const name = modal.result;
                dp.events.add({
                    start: args.start,
                    end: args.end,
                    resource: args.resource,
                    id: DayPilot.guid(),
                    text: name
                });
            },
            onBeforeHeaderRender: args => {
                args.header.areas = [
                    {
                        right: "5",
                        top: 5,
                        width: 30,
                        height: 30,
                        fontColor: "#999999",
                        symbol: "../icons/daypilot.svg#edit",
                        padding: 3,
                        cssClass: "icon",
                        toolTip: "Edit...",
                        onClick: async args => {
                            const form = [
                                {name: "Name", id: "name"},
                            ];
                            const data = args.source.data;
                            console.log(data);
                            const modal = await DayPilot.Modal.form(form, data);
                            if (modal.canceled) {
                                return;
                            }
                            const name = modal.result.name;
                            args.source.data.name = name;
                            dp.update();
                        }
                    }
                ];
            }
        });
        dp.init();

        const app = {
            loadEventData() {
                const events = [
                    {
                        start: "2022-06-24T12:00:00",
                        end: "2022-06-24T15:00:00",
                        resource: "B",
                        id: DayPilot.guid(),
                        text: "Room reservation"
                    }
                ];
                dp.update({events});
            },
            init() {
                this.loadEventData();
            }
        };
        app.init();
```