SSE using @microsoft/fetch-event-source so we can post and control …

…more (#193)

demo/sse.py

@@ -13,18 +13,11 @@
 async def canned_ai_response_generator() -> AsyncIterable[str]:
     prompt = '**User:** What is SSE? Please include a javascript code example.\n\n**AI:** '
     output = ''
-    msg = ''
     for time, text in chain([(0.5, prompt)], CANNED_RESPONSE):
         await asyncio.sleep(time)
         output += text
         m = FastUI(root=[c.Markdown(text=output)])
-        msg = f'data: {m.model_dump_json(by_alias=True, exclude_none=True)}\n\n'
-        yield msg
-
-    # avoid the browser reconnecting
-    while True:
-        yield msg
-        await asyncio.sleep(10)
+        yield f'data: {m.model_dump_json(by_alias=True, exclude_none=True)}\n\n'
 
 
 @router.get('/sse')

src/npm-fastui/package.json

@@ -21,6 +21,7 @@
     "typewatch": "tsc --noEmit --watch"
   },
   "dependencies": {
+    "@microsoft/fetch-event-source": "^2.0.1",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-markdown": "^9.0.1",

src/npm-fastui/src/components/ServerLoad.tsx

@@ -3,7 +3,7 @@ import { FC, useCallback, useContext, useEffect, useState } from 'react'
 import type { ServerLoad, PageEvent, FastProps } from '../models'
 
 import { ErrorContext } from '../hooks/error'
-import { useRequest, useSSE } from '../tools'
+import { useRequest, useSSE, Method } from '../tools'
 import { DefaultNotFound, DefaultTransition } from '../Defaults'
 import { ConfigContext } from '../hooks/config'
 import { usePageEventListen } from '../events'
@@ -14,36 +14,60 @@ import { AnyCompList } from './index'
 
 import { SpinnerComp } from './spinner'
 
-export const ServerLoadComp: FC<ServerLoad> = ({ path, components, loadTrigger, sse }) => {
+export const ServerLoadComp: FC<ServerLoad> = (props) => {
+  const { path, components, loadTrigger, sse, method, sseRetry } = props
   if (components) {
-    return <ServerLoadDefer path={path} components={components} loadTrigger={loadTrigger} sse={sse} />
+    return (
+      <ServerLoadDefer
+        path={path}
+        components={components}
+        loadTrigger={loadTrigger}
+        sse={sse}
+        method={method}
+        sseRetry={sseRetry}
+      />
+    )
   } else if (sse) {
-    return <ServerLoadSSE path={path} />
+    return <ServerLoadSSE path={path} method={method} sseRetry={sseRetry} />
   } else {
     return <ServerLoadFetch path={path} />
   }
 }
 
-const ServerLoadDefer: FC<{ path: string; components: FastProps[]; loadTrigger?: PageEvent; sse?: boolean }> = ({
-  components,
-  path,
-  loadTrigger,
-  sse,
-}) => {
+interface DeferProps {
+  path: string
+  components: FastProps[]
+  loadTrigger?: PageEvent
+  sse?: boolean
+  method?: Method
+  sseRetry?: number
+}
+
+const ServerLoadDefer: FC<DeferProps> = ({ components, path, loadTrigger, sse, method, sseRetry }) => {
   const { eventContext } = usePageEventListen(loadTrigger)
 
   if (eventContext) {
     return (
       <EventContextProvider context={eventContext}>
-        {sse ? <ServerLoadSSE path={path} /> : <ServerLoadFetch path={path} />}
+        {sse ? (
+          <ServerLoadSSE path={path} method={method} sseRetry={sseRetry} />
+        ) : (
+          <ServerLoadFetch path={path} method={method} />
+        )}
       </EventContextProvider>
     )
   } else {
     return <AnyCompList propsList={components} />
   }
 }
 
-export const ServerLoadFetch: FC<{ path: string; devReload?: number }> = ({ path, devReload }) => {
+interface FetchProps {
+  path: string
+  devReload?: number
+  method?: Method
+}
+
+export const ServerLoadFetch: FC<FetchProps> = ({ path, devReload, method }) => {
   const [transitioning, setTransitioning] = useState<boolean>(false)
   const [componentProps, setComponentProps] = useState<FastProps[] | null>(null)
   const [notFoundUrl, setNotFoundUrl] = useState<string | undefined>(undefined)
@@ -55,7 +79,7 @@ export const ServerLoadFetch: FC<{ path: string; devReload?: number }> = ({ path
   useEffect(() => {
     setTransitioning(true)
     let componentLoaded = true
-    request({ url, expectedStatus: [200, 345, 404] }).then(([status, data]) => {
+    request({ url, method, expectedStatus: [200, 345, 404] }).then(([status, data]) => {
       if (componentLoaded) {
         // 345 is treat the same as 200 - the server is expected to return valid FastUI components
         if (status === 200 || status === 345) {
@@ -80,7 +104,7 @@ export const ServerLoadFetch: FC<{ path: string; devReload?: number }> = ({ path
     return () => {
       componentLoaded = false
     }
-  }, [url, path, request, devReload])
+  }, [url, path, request, devReload, method])
 
   useEffect(() => {
     setNotFoundUrl(undefined)
@@ -89,12 +113,18 @@ export const ServerLoadFetch: FC<{ path: string; devReload?: number }> = ({ path
   return <Render propsList={componentProps} notFoundUrl={notFoundUrl} transitioning={transitioning} />
 }
 
-export const ServerLoadSSE: FC<{ path: string }> = ({ path }) => {
+interface SSEProps {
+  path: string
+  method?: Method
+  sseRetry?: number
+}
+
+export const ServerLoadSSE: FC<SSEProps> = ({ path, method, sseRetry }) => {
   const [componentProps, setComponentProps] = useState<FastProps[] | null>(null)
 
   const url = useServerUrl(path)
   const onMessage = useCallback((data: any) => setComponentProps(data as FastProps[]), [])
-  useSSE(url, onMessage)
+  useSSE(url, onMessage, method, sseRetry)
 
   return <Render propsList={componentProps} transitioning={false} />
 }

src/npm-fastui/src/models.d.ts

@@ -204,6 +204,8 @@ export interface ServerLoad {
   loadTrigger?: PageEvent
   components?: FastProps[]
   sse?: boolean
+  sseRetry?: number
+  method?: 'GET' | 'POST' | 'PATCH' | 'PUT' | 'DELETE'
   type: 'ServerLoad'
 }
 export interface Image {