When you write code to parse the custom data of a product, the code must contain a script that parses custom topic data and a script that parses Thing Specification Language (TSL) data. This topic provides complete sample JavaScript code.
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);
}