IoT Platform:Örnek JavaScript betiği

/**
 * Convert Alink data to data that can be recognized by a device when IoT Platform sends data to the device.
 * jsonObj: the input parameter. The value is a JSON object that cannot be empty. 
 * rawData: the output parameter. The value is a byte array that cannot be empty. 
 *
 */
function protocolToRawData(jsonObj) {
    return rawdata;
}

/**
 * Convert custom data of a device to Alink data when the device submits data to IoT Platform. 
 * rawData: the input parameter. The value is a byte array that cannot be empty. 
 * jsonObj: the output parameter. The value is a JSON object that cannot be empty. 
 */
function rawDataToProtocol(rawData) {
    return jsonObj;
}
            

var COMMAND_REPORT = 0x00; // Submit properties. 
var COMMAND_SET = 0x01; // Configure properties. 
var COMMAND_REPORT_REPLY = 0x02; // The data submission result. 
var COMMAND_SET_REPLY = 0x03; // The property setting result. 
var COMMAD_UNKOWN = 0xff;    // Unknown commands. 
var ALINK_PROP_REPORT_METHOD = 'thing.event.property.post'; // The topic that is used by devices to submit property data to IoT Platform. 
var ALINK_PROP_SET_METHOD = 'thing.service.property.set'; // The topic that is used by IoT Platform to send a property setting command to devices. 
var ALINK_PROP_SET_REPLY_METHOD = 'thing.service.property.set'; // The topic that is used by devices to submit the property setting results to IoT Platform. 
var SELF_DEFINE_TOPIC_UPDATE_FLAG = '/user/update'  // Define the following custom topic: /user/update. 
var SELF_DEFINE_TOPIC_ERROR_FLAG = '/user/update/error' // Define the following custom topic: /user/update/error. 
/*
Sample data:
Submit property data
Input:
    0x000000000100320100000000
Output:
    {"method":"thing.event.property.post","id":"1","params":{"prop_float":0,"prop_int16":50,"prop_bool":1},"version":"1.0"}

Result of property setting
Input:
    0x0300223344c8
Output:
    {"code":"200","data":{},"id":"2241348","version":"1.0"}
*/
function rawDataToProtocol(bytes) {
    var uint8Array = new Uint8Array(bytes.length);
    for (var i = 0; i < bytes.length; i++) {
        uint8Array[i] = bytes[i] & 0xff;
    }
    var dataView = new DataView(uint8Array.buffer, 0);
    var jsonMap = new Object();
    var fHead = uint8Array[0]; // command
    if (fHead == COMMAND_REPORT) {
        jsonMap['method'] = ALINK_PROP_REPORT_METHOD; // The topic that is used to submit properties. Data format: Alink JSON. 
        jsonMap['version'] = '1.0'; // The version of the protocol. This value is fixed. Data format: Alink JSON. 
        jsonMap['id'] = '' + dataView.getInt32(1); // The ID of the request. Data format: Alink JSON. 
        var params = {};
        params['prop_int16'] = dataView.getInt16(5); // The value of the prop_int16 property of the product. 
        params['prop_bool'] = uint8Array[7]; // The value of the prop_bool property of the product. 
        params['prop_float'] = dataView.getFloat32(8); // The value of the prop_float property of the product. 
        jsonMap['params'] = params; // The params field. Data format: Alink JSON. 
    } else if(fHead == COMMAND_SET_REPLY) {
        jsonMap['version'] = '1.0'; // The version of the protocol. This value is fixed. Data format: Alink JSON. 
        jsonMap['id'] = '' + dataView.getInt32(1); // The ID of the request. Data format: Alink JSON. 
        jsonMap['code'] = ''+ dataView.getUint8(5);
        jsonMap['data'] = {};
    }

    return jsonMap;
}
/*
Sample data:
Send downstream commands to configure device properties
Input:
    {"method":"thing.service.property.set","id":"12345","version":"1.0","params":{"prop_float":123.452, "prop_int16":333, "prop_bool":1}}
Output:
    0x0100003039014d0142f6e76d

Result of data submission
Input:
    {"method":"thing.event.property.post","id":"12345","version":"1.0","code":200,"data":{}}
Output:
    0x0200003039c8
*/
function protocolToRawData(json) {
    var method = json['method'];
    var id = json['id'];
    var version = json['version'];
    var payloadArray = [];
    if (method == ALINK_PROP_SET_METHOD) // Configure properties. 
    {
        var params = json['params'];
        var prop_float = params['prop_float'];
        var prop_int16 = params['prop_int16'];
        var prop_bool = params['prop_bool'];
        // Concatenate raw data based on the custom protocol format. 
        payloadArray = payloadArray.concat(buffer_uint8(COMMAND_SET)); // The command field. 
        payloadArray = payloadArray.concat(buffer_int32(parseInt(id))); // The ID of the request. Data format: Alink JSON. 
        payloadArray = payloadArray.concat(buffer_int16(prop_int16)); // The value of the prop_int16 property. 
        payloadArray = payloadArray.concat(buffer_uint8(prop_bool)); // The value of the prop_bool property. 
        payloadArray = payloadArray.concat(buffer_float32(prop_float)); // The value of the prop_float property. 
    } else if (method == ALINK_PROP_REPORT_METHOD) { // The response. 
        var code = json['code'];
        payloadArray = payloadArray.concat(buffer_uint8(COMMAND_REPORT_REPLY)); // The command field. 
        payloadArray = payloadArray.concat(buffer_int32(parseInt(id))); // The ID of the request. Data format: Alink JSON. 
        payloadArray = payloadArray.concat(buffer_uint8(code));
    } else { // Unknown commands. These commands are not processed. 
        var code = json['code'];
        payloadArray = payloadArray.concat(buffer_uint8(COMMAND_UNKOWN)); // The command field. 
        payloadArray = payloadArray.concat(buffer_int32(parseInt(id))); // The ID of the request. Data format: Alink JSON. 
        payloadArray = payloadArray.concat(buffer_uint8(code));
    }
    return payloadArray;
}

/*
  Sample data
  Use the following custom topic to submit data:
     /user/update. 
  Input:
     topic:/{productKey}/{deviceName}/user/update
     bytes: 0x000000000100320100000000
  Output:
  {
     "prop_float": 0,
     "prop_int16": 50,
     "prop_bool": 1,
     "topic": "/{productKey}/{deviceName}/user/update"
   }
 */
function transformPayload(topic, bytes) {
    var uint8Array = new Uint8Array(bytes.length);
    for (var i = 0; i < bytes.length; i++) {
        uint8Array[i] = bytes[i] & 0xff;
    }
    var dataView = new DataView(uint8Array.buffer, 0);
    var jsonMap = {};

    if(topic.includes(SELF_DEFINE_TOPIC_ERROR_FLAG)) {
        jsonMap['topic'] = topic;
        jsonMap['errorCode'] = dataView.getInt8(0)
    } else if (topic.includes(SELF_DEFINE_TOPIC_UPDATE_FLAG)) {
        jsonMap['topic'] = topic;
        jsonMap['prop_int16'] = dataView.getInt16(5);
        jsonMap['prop_bool'] = uint8Array[7];
        jsonMap['prop_float'] = dataView.getFloat32(8);
    }

    return jsonMap;
}

// The following code describes helper functions: 
function buffer_uint8(value) {
    var uint8Array = new Uint8Array(1);
    var dv = new DataView(uint8Array.buffer, 0);
    dv.setUint8(0, value);
    return [].slice.call(uint8Array);
}
function buffer_int16(value) {
    var uint8Array = new Uint8Array(2);
    var dv = new DataView(uint8Array.buffer, 0);
    dv.setInt16(0, value);
    return [].slice.call(uint8Array);
}
function buffer_int32(value) {
    var uint8Array = new Uint8Array(4);
    var dv = new DataView(uint8Array.buffer, 0);
    dv.setInt32(0, value);
    return [].slice.call(uint8Array);
}
function buffer_float32(value) {
    var uint8Array = new Uint8Array(4);
    var dv = new DataView(uint8Array.buffer, 0);
    dv.setFloat32(0, value);
    return [].slice.call(uint8Array);
}