feat: add popperTargetRef prop for custom popper positioning

docs-site/src/components/Examples/config.tsx

@@ -15,6 +15,7 @@ import CloseOnScroll from "../../examples/ts/closeOnScroll?raw";
 import CloseOnScrollCallback from "../../examples/ts/closeOnScrollCallback?raw";
 import ConfigureFloatingUI from "../../examples/ts/configureFloatingUI?raw";
 import CustomInput from "../../examples/ts/customInput?raw";
+import PopperTargetRef from "../../examples/ts/popperTargetRef?raw";
 import RenderCustomHeader from "../../examples/ts/renderCustomHeader?raw";
 import RenderCustomHeaderTwoMonths from "../../examples/ts/renderCustomHeaderTwoMonths?raw";
 import RenderCustomDayName from "../../examples/ts/renderCustomDayName?raw";
@@ -178,6 +179,12 @@ export const EXAMPLE_CONFIG: IExampleConfig[] = [
     title: "Custom input",
     component: CustomInput,
   },
+  {
+    title: "Custom input with popper positioning",
+    component: PopperTargetRef,
+    description:
+      "Use popperTargetRef to position the calendar relative to a specific element within your custom input, rather than the wrapper div.",
+  },
   {
     title: "Custom header",
     component: RenderCustomHeader,

docs-site/src/examples/ts/popperTargetRef.tsx

@@ -0,0 +1,60 @@
+/**
+ * When using a customInput with multiple elements (like a text display and a button),
+ * you can use popperTargetRef to control which element the calendar positions relative to.
+ *
+ * Without popperTargetRef, the calendar positions relative to the wrapper div.
+ * With popperTargetRef, it positions relative to the specific element you choose.
+ */
+
+type CustomInputWithButtonProps = {
+  value?: string;
+  onClick?: () => void;
+  buttonRef?: React.RefObject<HTMLButtonElement | null>;
+};
+
+const CustomInputWithButton: React.FC<CustomInputWithButtonProps> = ({
+  value,
+  onClick,
+  buttonRef,
+}) => (
+  <div
+    style={{
+      display: "flex",
+      alignItems: "center",
+      gap: "8px",
+      padding: "8px",
+      border: "1px solid #ccc",
+      borderRadius: "4px",
+      width: "250px",
+    }}
+  >
+    <span style={{ flex: 1 }}>{value || "Select a date"}</span>
+    <button
+      ref={buttonRef}
+      onClick={onClick}
+      type="button"
+      style={{
+        padding: "4px 8px",
+        cursor: "pointer",
+      }}
+    >
+      📅
+    </button>
+  </div>
+);
+
+const PopperTargetRef = () => {
+  const [selectedDate, setSelectedDate] = useState<Date | null>(new Date());
+  const buttonRef = useRef<HTMLButtonElement>(null);
+
+  return (
+    <DatePicker
+      selected={selectedDate}
+      onChange={setSelectedDate}
+      customInput={<CustomInputWithButton buttonRef={buttonRef} />}
+      popperTargetRef={buttonRef}
+    />
+  );
+};
+
+render(PopperTargetRef);

src/index.tsx

@@ -149,6 +149,7 @@ export type DatePickerProps = OmitUnion<
     onKeyDown?: (event: React.KeyboardEvent<HTMLElement>) => void;
     popperClassName?: PopperComponentProps["className"];
     showPopperArrow?: PopperComponentProps["showArrow"];
+    popperTargetRef?: React.RefObject<HTMLElement | null>;
     open?: boolean;
     disabled?: boolean;
     readOnly?: boolean;

src/popper_component.tsx

@@ -1,6 +1,6 @@
 import { FloatingArrow } from "@floating-ui/react";
 import { clsx } from "clsx";
-import React, { createElement } from "react";
+import React, { createElement, useEffect } from "react";
 
 import Portal from "./portal";
 import TabLoop from "./tab_loop";
@@ -28,6 +28,7 @@ interface PopperComponentProps
   popperOnKeyDown: React.KeyboardEventHandler<HTMLDivElement>;
   showArrow?: boolean;
   portalId?: PortalProps["portalId"];
+  popperTargetRef?: React.RefObject<HTMLElement | null>;
   monthHeaderPosition?: "top" | "middle" | "bottom";
 }
 
@@ -45,9 +46,19 @@ export const PopperComponent: React.FC<PopperComponentProps> = (props) => {
     portalHost,
     popperProps,
     showArrow,
+    popperTargetRef,
     monthHeaderPosition,
   } = props;
 
+  // When a custom popperTargetRef is provided, use it as the position reference
+  // This allows the popper to be positioned relative to a specific element
+  // within the custom input, rather than the wrapper div
+  useEffect(() => {
+    if (popperTargetRef?.current) {
+      popperProps.refs.setPositionReference(popperTargetRef.current);
+    }
+  }, [popperTargetRef, popperProps.refs]);
+
   let popper: React.ReactElement | undefined = undefined;
 
   if (!hidePopper) {

src/test/datepicker_test.test.tsx

@@ -293,6 +293,52 @@ describe("DatePicker", () => {
     expect(popper[0]?.classList.contains("some-class-name")).toBe(true);
   });
 
+  it("should use popperTargetRef for positioning when provided", () => {
+    const buttonRef = React.createRef<HTMLButtonElement>();
+
+    /* eslint-disable react-hooks/refs -- passing ref object and callbacks as props, not accessing .current */
+    // Custom input component that exposes a button ref separately from the main input ref
+    const CustomInputWithButton: React.FC<{
+      value?: string;
+      onClick?: () => void;
+      buttonRef?: React.RefObject<HTMLButtonElement | null>;
+    }> = (props) => {
+      return (
+        <div style={{ display: "flex", width: "300px" }}>
+          <input value={props.value || ""} readOnly onClick={props.onClick} />
+          <button
+            ref={props.buttonRef}
+            onClick={props.onClick}
+            data-testid="custom-button"
+          >
+            Open
+          </button>
+        </div>
+      );
+    };
+    /* eslint-enable react-hooks/refs */
+
+    const { container } = render(
+      <DatePicker
+        customInput={<CustomInputWithButton buttonRef={buttonRef} />}
+        popperTargetRef={buttonRef}
+      />,
+    );
+
+    const button = safeQuerySelector<HTMLButtonElement>(
+      container,
+      '[data-testid="custom-button"]',
+    );
+    fireEvent.click(button);
+
+    // Verify the popper is shown
+    const popper = container.querySelector(".react-datepicker-popper");
+    expect(popper).not.toBeNull();
+
+    // Verify the button ref was properly set
+    expect(buttonRef.current).toBe(button);
+  });
+
   it("should show the calendar when clicking on the date input", () => {
     const { container } = render(<DatePicker />);