ESPAsyncWebServer/docs/index.md

# ESP Async WebServer

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Async Web Server for ESP31B

This fork is based on https://github.com/yubox-node-org/ESPAsyncWebServer and includes all the concurrency fixes.

## Changes in this fork

- Removed SPIFFSEditor
- Deployed in PlatformIO registry and Arduino IDE library manager
- CI
- Some code cleanup
- `SSE_MAX_QUEUED_MESSAGES` to control the maximum number of messages that can be queued for a SSE client
- `write()` function public in `AsyncEventSource.h`
- Arduino Json 7 compatibility and by default, still compatible with 6 (`AsyncJson.h`)
- `WS_MAX_QUEUED_MESSAGES`: control the maximum number of messages that can be queued for a Websocket client
- Resurrected `AsyncWebSocketMessageBuffer` and `makeBuffer()` in order to make the fork API-compatible with the original library from me-no-dev regarding WebSocket.
- [#5](https://github.com/mathieucarbou/ESPAsyncWebServer/pull/5): set real "Last-Modified" header based on file's LastWrite time ([@vortigont](https://github.com/vortigont))

## Documentation

Usage and API stays the same as the original library.
Please look at the original libraries for more examples and documentation.

[https://github.com/yubox-node-org/ESPAsyncWebServer](https://github.com/yubox-node-org/ESPAsyncWebServer)

## `AsyncWebSocketMessageBuffer` and `makeBuffer()`

The fork from `yubox-node-org` introduces some breaking API changes compared to the original library, especially regarding the use of `std::shared_ptr<std::vector<uint8_t>>` for WebSocket.

This fork is compatible with the original library from `me-no-dev` regarding WebSocket, and wraps the optimizations done by `yubox-node-org` in the `AsyncWebSocketMessageBuffer` class.
So you have the choice of which API to use.
I strongly suggest to use the optimized API from `yubox-node-org` as it is much more efficient.

Here is an example for serializing a Json document in a websocket message buffer. This code is compatible with any forks, but not optimized:

```cpp
void send(JsonDocument& doc) {
  const size_t len = measureJson(doc);

  // original API from me-no-dev
  AsyncWebSocketMessageBuffer* buffer = _ws->makeBuffer(len);
  assert(buffer); // up to you to keep or remove this
  serializeJson(doc, buffer->get(), len);
  _ws->textAll(buffer);
}
```

Here is an example for serializing a Json document in a more optimized way, and compatible with both forks:

```cpp
void send(JsonDocument& doc) {
  const size_t len = measureJson(doc);

#if defined(ASYNCWEBSERVER_FORK_mathieucarbou)

  // this fork (originally from yubox-node-org), uses another API with shared pointer that better support concurrent use cases then the original project
  auto buffer = std::make_shared<std::vector<uint8_t>>(len);
  assert(buffer); // up to you to keep or remove this
  serializeJson(doc, buffer->data(), len);
  _ws->textAll(std::move(buffer));

#else

  // original API from me-no-dev
  AsyncWebSocketMessageBuffer* buffer = _ws->makeBuffer(len);
  assert(buffer); // up to you to keep or remove this
  serializeJson(doc, buffer->get(), len);
  _ws->textAll(buffer);

#endif
}
```