ESP32_ChinaDieselHeater_Con.../lib/asyncHTTPrequest/sample/sample.cpp
2020-01-04 18:13:40 +11:00

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2.6 KiB
C++

//************************************************************************************************************
//
// There are scores of ways to use asyncHTTPrequest. The important thing to keep in mind is that
// it is asynchronous and just like in JavaScript, everything is event driven. You will have some
// reason to initiate an asynchronous HTTP request in your program, but then sending the request
// headers and payload, gathering the response headers and any payload, and processing
// of that response, can (and probably should) all be done asynchronously.
//
// In this example, a Ticker function is setup to fire every 5 seconds to initiate a request.
// Everything is handled in asyncHTTPrequest without blocking.
// The callback onReadyStateChange is made progressively and like most JS scripts, we look for
// readyState == 4 (complete) here. At that time the response is retrieved and printed.
//
// Note that there is no code in loop(). A code entered into loop would run oblivious to
// the ongoing HTTP requests. The Ticker could be removed and periodic calls to sendRequest()
// could be made in loop(), resulting in the same asynchronous handling.
//
// For demo purposes, debug is turned on for handling of the first request. These are the
// events that are being handled in asyncHTTPrequest. They all begin with Debug(nnn) where
// nnn is the elapsed time in milliseconds since the transaction was started.
//
//*************************************************************************************************************
#include <ESP8266WiFi.h>
#include <WiFiManager.h>
#include <asyncHTTPrequest.h>
#include <Ticker.h>
WiFiManager wifiManager;
asyncHTTPrequest request;
Ticker ticker;
void sendRequest(){
if(request.readyState() == 0 || request.readyState() == 4){
request.open("GET", "http://worldtimeapi.org/api/timezone/Europe/London.txt");
request.send();
}
}
void requestCB(void* optParm, asyncHTTPrequest* request, int readyState){
if(readyState == 4){
Serial.println(request->responseText());
Serial.println();
request->setDebug(false);
}
}
void setup(){
Serial.begin(115200);
WiFi.setAutoConnect(true);
WiFi.begin();
while(WiFi.status() != WL_CONNECTED){
wifiManager.setDebugOutput(false);
wifiManager.setConfigPortalTimeout(180);
Serial.println("Connecting with WiFiManager");
wifiManager.autoConnect("ESP8266", "ESP8266");
yield();
}
request.setDebug(true);
request.onReadyStateChange(requestCB);
ticker.attach(5, sendRequest);
}
void loop(){
}