ESP32 web server HTTP learning with BME280

I need a web server on esp32/8266 to work as user interface for config wifi(mode, ssid, pwd) as well we some parameter useful for program usage, and then store it in flash of the chip.

I used to use PyBBIO web server on bone or pi, without knowing the basic. Now I have to go into it and find a good one on esp. I have look into the lib of esp32 arduino, there is a simple wifiserver, but too simple and I lack of HTTP knowage.
Here is very good one: https://startingelectronics.org/tutorials/arduino/ethernet-shield-web-server-tutorial/basic-web-server/

and for ESP32 webserver,Then I found this:

so he used a library called https://github.com/bbx10/WebServer_tng , which works on 8266 and ESP32, and he also has a sd webserver, seems reallly interesting
https://github.com/bbx10/WebServer_tng/blob/master/examples/SDWebServer/SDWebServer.ino

I tried his example, http://educ8s.tv/wp-content/uploads/2017/11/ESP32-Web-Server.zip
it did not compile, and come with an error on no matching function for call to 'Adafruit_BME280::Adafruit_BME280(int, int)' I did not understand why for quite a long time, and struggle with adafruit lib for IIC, to find a way to assign the IIC pins. I finally found that he use another modified adafruit BME280 lib https://github.com/Takatsuki0204/BME280-I2C-ESP32

I tried to understand what he modified in the cpp:
in the private function:
orignal is :

Adafruit_BME280::Adafruit_BME280()
	: _cs(-1), _mosi(-1), _miso(-1), _sck(-1)
	{ }

He changed to :

Adafruit_BME280::Adafruit_BME280(uint8_t sda, uint8_t scl)
	: _cs(-1), _mosi(-1), _miso(-1), _sck(-1), pinSDA(sda), pinSCL(scl)
	{ }

This explain how he got the function to use Adafruit_BME280(int, int)


The in the begin he also change to :

bool Adafruit_BME280::begin(uint8_t addr)
	{
	_i2caddr = addr;
	// init I2C or SPI sensor interface
	if (_cs == -1) {
	// I2C
	Wire.begin(pinSDA, pinSCL);
	} else {
	digitalWrite(_cs, HIGH);
	pinMode(_cs, OUTPUT);
	if (_sck == -1) {
	// hardware SPI
	SPI.begin();
	} else {
	// software SPI
	pinMode(_sck, OUTPUT);
	pinMode(_mosi, OUTPUT);
	pinMode(_miso, INPUT);
	}
	}

This is how he got the begin with assigned IIC pins.

So, I removed the original one of adfruit to avoid conflict. and install Takatsuki version, modi the SDA to 4 and SCL to 15, BME280 works fine on my heltec 8266 board.
But in the latest version of adafruit lib, there is a way to assign pins, just I did not understand how this is done:

bool Adafruit_BME280::begin(uint8_t addr, TwoWire *theWire)
	{
	_i2caddr = addr;
	_wire = theWire;
	return init();
	}

Then run the server again(with modi on IIC pins), it works correctly....


Other web server lib
fro IOTsharing: https://github.com/nhatuan84/esp32-webserver