ArduinoJsonWriter

Json Writer is a light weight library that make it easier to generate json document on Arduino.

The library works pretty similar to the SAX for XML, it treats JSON as a stream of nodes. With the API, you can compose a JSON document by emitting each node.

Initialize JsonWriter

JsonWriter wraps a Stream instance, so it could be used to generate data for all kind of Stream based IO or starages, including: Serial, Wire(I2C), Ethernet TCP socket, SD

JsonWriter serialJsonWriter(Serial);

JsonWriter wireJsonWriter(Wire);

JsonWriter ethernetJsonWriter1(ethernetClient);

JsonWriter ethernetJsonWriter2(ethernetServer);

Usage

Emit Primitives

writer.string("Json String");           // "Json String"
writer.string("0x" + String(255,HEX));  // "0xFF"
writer.number(23);						 // 23
writer.null();							 // null
writer.boolean(true);					 // true	
writer.boolean(false);					 // false

Emit Array

writer
  .beginArray()
  .string("alpha")
  .string("beta")
  .null()
  .string("gamma")
  .number(123)
  .endArray(); 					        
  // ["aplha","beta",null,"gamma",123]

Emit Object

writer
  .beginObject()
        .property("Real name","Thomas A. Anderson")
        .property("Hacker name","Neo")
        .property("Entity","The One")
        .property("Height",185)
        .property("isCreatedByArchitect",true)
  .endObject(); 
  
  // {"Real name":"Thomas A. Anderson","Hacker name":"Neo","Entity":"The One","Height":185,"isCreatedByArchitect":true}

Array of objects

writer
  .beginArray()
        .beginObject()
            .property("name", "alpha")
        .endObject()
        .beginObject()
            .property("name", "beta")
            .property("anotherProperty", 12.67)
        .endObject()
        .beginObject()
            .property("name", "gamma")
        .endObject()
  .endArray(); 					        
  // [{"name":"alpha"},{"name":"beta","anotherProperty":12.67},{"name":"gamma"}]

Nested Objects and arrays

writer
  .beginObject()
    .property("id", 7)
    .beginObject("name")
            .property("firstName","James")
            .property("lastName","Bond")
        .endObject()
        .beginArray("languages")
            .string("English")
            .string("Russian")
        .endArray()
        .beginArray("gadgets")
            .beginObject()
                .property("name", "Laser watch")
                .property("returned", false)
            .endObject()
            .beginObject()
                .property("name", "Walther PP")
                .property("returned", false)
                .beginArray("calibers")
                    .number(32)
                    .number(380)
                    .number(22)
                .endArray()
            .endObject()
        .endArray()
  .endObject(); 
  
  // {"id":7,"name":{"firstName":"James","lastName":"Bond"},"languages":["English","Russian"],"gadgets":[{"name":"Laser watch","returned":0},{"name":"Walther PP","returned":0,"calibers":[32,380,22]}]}