gistfile1.cpp

// Helper class so we can send AP scan results in an easier way
class JsonObjectAsyncStream : public JsonObjectStream
{
public:
	virtual ~JsonObjectAsyncStream();
	virtual uint16_t readMemoryBlock(char* data, int bufSize);
	virtual bool isFinished();
	void setCanSend();
private:
	bool can_send = false;
};

uint16_t JsonObjectAsyncStream::readMemoryBlock(char* data, int bufSize) {
	Debug.println("read mem block");
	if(can_send) return JsonObjectStream::readMemoryBlock(data, bufSize);
	else return MemoryDataStream::readMemoryBlock(data, bufSize);
}

bool JsonObjectAsyncStream::isFinished() {
	if(can_send) return JsonObjectStream::isFinished();
	else return false;
}

void JsonObjectAsyncStream::setCanSend() {
	can_send = true;
}

JsonObjectAsyncStream::~JsonObjectAsyncStream() {
	if (can_send) Debug.println("async stream destroyed after can_send");
	else Debug.println("async stream destroyed before can_send");
}

// HOW IT IS USED
// scanreq_stream is a field of the WebUI class
void WebUI::onScanAP(HttpRequest &request, HttpResponse &response) {
	if(scanreq_stream == nullptr) {
		scanreq_stream = new JsonObjectAsyncStream();
		WifiStation.startScan(ScanCompletedDelegate(&WebUI::onAPscanned, this));
	}
	response.sendDataStream(scanreq_stream, MIME_JSON);
}

void WebUI::onAPscanned(bool succeeded, BssList list) {
	// serialize the network list
	JsonObject& json = scanreq_stream->getRoot();
	JsonArray& array = json.createNestedArray("networks");
	for (int i = 0; i < list.count(); i++)
	{
		JsonObject& ap = array.createNestedObject();
		ap["ssid"] = list[i].ssid;
		ap["channel"] = list[i].channel;
		ap["rssi"] = list[i].rssi;
		ap["auth"] = list[i].getAuthorizationMethodName();
		ap["hidden"] = list[i].hidden;
	}
	scanreq_stream->setCanSend();
	scanreq_stream = nullptr;
}