From dff08ae3e3f36ce4a798d9808756cab45ed36054 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Greg=20Berg=C3=A9?= <berge.greg@gmail.com>
Date: Thu, 30 Jan 2025 15:01:59 +0100
Subject: [PATCH] Load Scalar only when the button is pressed (#2790)

---
 .changeset/selfish-badgers-smile.md           |  5 ++
 .../react-openapi/src/OpenAPICodeSample.tsx   |  6 +-
 .../react-openapi/src/OpenAPIOperation.tsx    | 68 +++++++--------
 .../react-openapi/src/ScalarApiButton.tsx     | 86 +++++++++++++++++--
 4 files changed, 120 insertions(+), 45 deletions(-)
 create mode 100644 .changeset/selfish-badgers-smile.md

diff --git a/.changeset/selfish-badgers-smile.md b/.changeset/selfish-badgers-smile.md
new file mode 100644
index 000000000..58a5f9e55
--- /dev/null
+++ b/.changeset/selfish-badgers-smile.md
@@ -0,0 +1,5 @@
+---
+'@gitbook/react-openapi': patch
+---
+
+Improve performances by loading Scalar API Client only when the button is clicked
diff --git a/packages/react-openapi/src/OpenAPICodeSample.tsx b/packages/react-openapi/src/OpenAPICodeSample.tsx
index 5b1118d59..8ed04e303 100644
--- a/packages/react-openapi/src/OpenAPICodeSample.tsx
+++ b/packages/react-openapi/src/OpenAPICodeSample.tsx
@@ -123,7 +123,11 @@ export function OpenAPICodeSample(props: {
             tabs={samples}
             overlay={
                 data['x-hideTryItPanel'] || data.operation['x-hideTryItPanel'] ? null : (
-                    <ScalarApiButton method={data.method} path={data.path} />
+                    <ScalarApiButton
+                        method={data.method}
+                        path={data.path}
+                        specUrl={context.specUrl}
+                    />
                 )
             }
         />
diff --git a/packages/react-openapi/src/OpenAPIOperation.tsx b/packages/react-openapi/src/OpenAPIOperation.tsx
index 618a3cf06..ffb2269d6 100644
--- a/packages/react-openapi/src/OpenAPIOperation.tsx
+++ b/packages/react-openapi/src/OpenAPIOperation.tsx
@@ -1,6 +1,5 @@
 import * as React from 'react';
 import classNames from 'classnames';
-import { ApiClientModalProvider } from '@scalar/api-client-react';
 
 import { OpenAPIOperationData } from './fetchOpenAPIOperation';
 import { Markdown } from './Markdown';
@@ -28,45 +27,40 @@ export function OpenAPIOperation(props: {
     };
 
     return (
-        <ApiClientModalProvider
-            configuration={{ spec: { url: context.specUrl } }}
-            initialRequest={{ path: data.path, method: data.method }}
-        >
-            <div className={classNames('openapi-operation', className)}>
-                <div className="openapi-intro">
-                    <h2 className="openapi-summary" id={context.id}>
-                        {operation.summary}
-                    </h2>
-                    {operation.description ? (
-                        <Markdown className="openapi-description" source={operation.description} />
-                    ) : null}
-                    <div className="openapi-target">
-                        <span
-                            className={classNames(
-                                'openapi-method',
-                                `openapi-method-${method.toLowerCase()}`,
-                            )}
-                        >
-                            {method.toUpperCase()}
-                        </span>
-                        <span className="openapi-url">
-                            <OpenAPIServerURL servers={servers} />
-                            {path}
-                        </span>
-                    </div>
+        <div className={classNames('openapi-operation', className)}>
+            <div className="openapi-intro">
+                <h2 className="openapi-summary" id={context.id}>
+                    {operation.summary}
+                </h2>
+                {operation.description ? (
+                    <Markdown className="openapi-description" source={operation.description} />
+                ) : null}
+                <div className="openapi-target">
+                    <span
+                        className={classNames(
+                            'openapi-method',
+                            `openapi-method-${method.toLowerCase()}`,
+                        )}
+                    >
+                        {method.toUpperCase()}
+                    </span>
+                    <span className="openapi-url">
+                        <OpenAPIServerURL servers={servers} />
+                        {path}
+                    </span>
                 </div>
-                <div className={classNames('openapi-columns')}>
-                    <div className={classNames('openapi-column-spec')}>
-                        <OpenAPISpec data={data} context={clientContext} />
-                    </div>
-                    <div className={classNames('openapi-column-preview')}>
-                        <div className={classNames('openapi-column-preview-body')}>
-                            <OpenAPICodeSample {...props} />
-                            <OpenAPIResponseExample {...props} />
-                        </div>
+            </div>
+            <div className={classNames('openapi-columns')}>
+                <div className={classNames('openapi-column-spec')}>
+                    <OpenAPISpec data={data} context={clientContext} />
+                </div>
+                <div className={classNames('openapi-column-preview')}>
+                    <div className={classNames('openapi-column-preview-body')}>
+                        <OpenAPICodeSample {...props} />
+                        <OpenAPIResponseExample {...props} />
                     </div>
                 </div>
             </div>
-        </ApiClientModalProvider>
+        </div>
     );
 }
diff --git a/packages/react-openapi/src/ScalarApiButton.tsx b/packages/react-openapi/src/ScalarApiButton.tsx
index 074fc32fe..bc6650eca 100644
--- a/packages/react-openapi/src/ScalarApiButton.tsx
+++ b/packages/react-openapi/src/ScalarApiButton.tsx
@@ -1,23 +1,33 @@
 'use client';
 
-import { useApiClientModal } from '@scalar/api-client-react';
-import React from 'react';
+import { ApiClientModalProvider, useApiClientModal } from '@scalar/api-client-react';
+import React, { useImperativeHandle, useRef } from 'react';
+import { createPortal } from 'react-dom';
 
 import { useOpenAPIOperationContext } from './OpenAPIOperationContext';
+import { useEventCallback } from 'usehooks-ts';
 
 /**
  * Button which launches the Scalar API Client
  */
-export function ScalarApiButton({ method, path }: { method: string; path: string }) {
-    const client = useApiClientModal();
-    const { onOpenClient } = useOpenAPIOperationContext();
+export function ScalarApiButton({
+    method,
+    path,
+    specUrl,
+}: {
+    method: string;
+    path: string;
+    specUrl: string;
+}) {
+    const [isOpen, setIsOpen] = React.useState(false);
+    const controllerRef = useRef<ScalarModalControllerRef>(null);
     return (
         <div className="scalar scalar-activate">
             <button
                 className="scalar-activate-button"
                 onClick={() => {
-                    client?.open({ method, path });
-                    onOpenClient({ method, path });
+                    controllerRef.current?.openClient?.();
+                    setIsOpen(true);
                 }}
             >
                 <svg xmlns="http://www.w3.org/2000/svg" width="10" height="12" fill="none">
@@ -29,6 +39,68 @@ export function ScalarApiButton({ method, path }: { method: string; path: string
                 </svg>
                 Test it
             </button>
+
+            {isOpen &&
+                createPortal(
+                    <ScalarModal
+                        controllerRef={controllerRef}
+                        method={method}
+                        path={path}
+                        specUrl={specUrl}
+                    />,
+                    document.body,
+                )}
         </div>
     );
 }
+
+function ScalarModal(props: {
+    method: string;
+    path: string;
+    specUrl: string;
+    controllerRef: React.Ref<ScalarModalControllerRef>;
+}) {
+    return (
+        <ApiClientModalProvider
+            configuration={{ spec: { url: props.specUrl } }}
+            initialRequest={{ path: props.path, method: props.method }}
+        >
+            <ScalarModalController
+                method={props.method}
+                path={props.path}
+                controllerRef={props.controllerRef}
+            />
+        </ApiClientModalProvider>
+    );
+}
+
+type ScalarModalControllerRef = {
+    openClient: (() => void) | undefined;
+};
+
+function ScalarModalController(props: {
+    method: string;
+    path: string;
+    controllerRef: React.Ref<ScalarModalControllerRef>;
+}) {
+    const client = useApiClientModal();
+    const openClient = client?.open;
+    useImperativeHandle(
+        props.controllerRef,
+        () => ({ openClient: openClient ? () => openClient() : undefined }),
+        [openClient],
+    );
+
+    // Open the client when the component is mounted.
+    const { onOpenClient } = useOpenAPIOperationContext();
+    const trackOpening = useEventCallback(() => {
+        onOpenClient({ method: props.method, path: props.path });
+    });
+    React.useEffect(() => {
+        if (openClient) {
+            openClient();
+            trackOpening();
+        }
+    }, [openClient]);
+    return null;
+}