Add ability to get raw http request body

[avr39-ripe]

It is really cleaned version of PR #272 by @dereulenspiegel. I just polish it and remove unwanted formatting. It intendet to return raw http request body for further parsing, for example by ArduinoJson library. I think that POST-ing json from web is much more efficient and can send more complex and structured data than formURLencoded content-type. Moreover, by adding just little JS-code on frontend (web-page) we can make some data validation/modification/processing before sending to esp8266 web-server and off-load our little buddy on client (more powerful in fact!) :)

[avr39-ripe]

sniplet for using above feature

in webserver handling code for some url:

   if (request.getBody() == NULL)
            Serial.println("NULL bodyBuf");
        else
        {
            StaticJsonBuffer<200> jsonBuffer;
            JsonObject& root = jsonBuffer.parseObject(request.getBody());
            root.prettyPrintTo(Serial);

            if (root["start_minutes"].success()) // Settings
            {
                ActiveConfig.start_minutes = root["start_minutes"];
                ActiveConfig.stop_minutes = root["stop_minutes"];
                ActiveConfig.cycle_duration = root["cycle_duration"];
                ActiveConfig.cycle_interval = root["cycle_interval"];
            }
        }
        saveConfig(ActiveConfig);

in submit form event handling we can send form in json as

function post_cfg(event) {
    event.preventDefault();
    var formData = {
            'start_minutes'             :   document.getElementById('start_minutes').value,
            'stop_minutes'              :   document.getElementById('stop_minutes').value,
            'cycle_duration'            :   document.getElementById('cycle_duration').value,
            'cycle_interval'            :   document.getElementById('cycle_interval').value
            };
    $.ajax({
        type        : 'POST',
        url         : '/config',
        contentType : 'application/json; charset=utf-8',
        data        : JSON.stringify(formData),
        dataType    : 'json'
    })
}

you may ask WHAT is the proffit of whole this stuff instead of simply use HTML FORMS? - you can as I said validate values more deeply then even html5 inputs allow, you can pre-proccess form data and send result, you can send more complex data from page to server, you can talk with some REST server (may be one made from esp8266) in more native, json manner and so on..

[alonewolfx2]

seems clean and helpfull for http requests. i will test it tonight.

[hreintke]

@alonewolfx2 : @avr39-ripe :

• Does this obsolete Access to HTTP POST body #272 completely ?
• Has this already been tested ?
• Can you add the sniplet to an example or provide a new example showing this functionality
• Can you squash the commits into one ?

[avr39-ripe]

@hreintke this #499 is squashed version as you requested
in addition there is example to demonstrate this and several other features and concepts, I try to make example small, simple, but reusable.
it fully obsolets #272 (but I mention again to be honest, I'm not the author of this feature, I just gather and clean things)
I test it and it works on real hardware.

[hreintke]

Solved by #499 & #578