Validating the return of an HTTP GET request with arduino IDE and nodemcu-esp-12e

Question

Using the Arduino IDE with the Nodemcu-esp12e module, I created a program which makes an HTTP GET request.

However, I do not know how it would be the right way to deal with the return of this consultation.

I am validating the return with the 'indexOf' function to find out if the return is false/off or true/on.

This is the correct way to validate the return?
Any suggestions for how to improve this code?

#include <ESP8266WiFi.h>
const char* ssid     = "mywifiid";
const char* password = "mypassword";
IPAddress host(192,168,0,11); 

void setup() {
  Serial.begin(115200);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  //
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  //
  Serial.println("");
  Serial.println("WiFi connected");  
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  //
  Serial.print("connecting to ");
  Serial.println(host);
  //
  WiFiClient client;
  const int httpPort = 80;
  if (!client.connect(host, httpPort)) {
    Serial.println("connection failed");
    return;
  }
  else{
    Serial.println("connection success");
  }
  //
  String get = "http://localhost/Test/GetStatusSensor?idsensor=2";
  Serial.println(get);
  //
  client.print("GET " + get + "\r\nHTTP/1.1\r\nHost: localhost\Test\r\nConnection: keep-alive\r\n\r\n");
  //
  while(client.available()){
    String line = client.readStringUntil('\r');
    //
    int iret= line.indexOf('on');
    //
    Serial.print(line);
    Serial.println(String(iret));
    //
    if (iret> 0) {
      //
      Serial.println("On");
    }
    else {
      Serial.println("Off");
    }    
  }
  //
  Serial.println();
  Serial.println("closing connection");
  delay(20000);  // 20 sec
}

http://stackoverflow.com/questions/11812850/does-arduino-use-c-or-c — Sr Julien, Sep 27 '16 at 17:19
The accepted answer is plain wrong. Arduino is a C++ derivate (which implies not exactly C++). And C being a subset of C++ is plain nonsense! Identical syntax does not imply identical semantics. Whoever this states does not know at least one of them well enough to write much more than a "Hello World". There are much better Q&A regarding this subject. FYI: That answer has 20 downvotes, the highest ranked answer none - for good reason! — too honest for this site, Sep 27 '16 at 17:40
Well I believe this will help the question: http://www.nongnu.org/avr-libc/user-manual/index.html — Sr Julien, Sep 27 '16 at 17:46
The code above is definitively **not** C! I will not discuss this any further! — too honest for this site, Sep 27 '16 at 17:47
I am not here arguing, I'm trying to reach a consensus about what runs on Arduino language! — Sr Julien, Sep 27 '16 at 17:50
Read the info page, learn C, learn C++, learn how you can use libraries from one language in the other (as you can do with libs written in any other compiled language if they use the same ABI). This is neither a discussion forum, nor a tutoring site. Don't add tags for unrelated languages! — too honest for this site, Sep 27 '16 at 17:53

cagdas · Accepted Answer · 2017-04-11T05:23:56.737

My suggestion is to use JSON to switch to more structured way of comm. You can define custom data names and types and easily cover them. Take a look it at :

https://github.com/bblanchon/ArduinoJson

Here some JSON example from the HTTPClient example :

  DynamicJsonBuffer jsonBuffer(BUFFER_SIZE);

  JsonObject& root = jsonBuffer.parseObject(client);

  if (!root.success()) {
    Serial.println("JSON parsing failed!");
    return false;
  }

  // Here were copy the strings we're interested in
  strcpy(userData->name, root["name"]);
  strcpy(userData->company, root["company"]["name"]);

Validating the return of an HTTP GET request with arduino IDE and nodemcu-esp-12e

1 Answers1