More documentation and added node async functionality

src/connector/nodejs/nodetaos/cursor.js

@@ -1,72 +1,104 @@
 const CTaosInterface = require('./cinterface')
 const errors = require ('./error')
+const TaosQuery = require('./taosquery')
 module.exports = TDengineCursor;
 
+/**
+ * Constructor for a TDengine Cursor
+ * @class TDengineCursor
+ * @constructor
+ * @param {TDengineConnection} - The TDengine Connection this cursor uses to interact with TDengine
+ * @property {data} - Latest retrieved data from query execution. It is an empty array by default
+ * @property {fieldNames} - Array of the field names in order from left to right of the latest data retrieved
+ */
 function TDengineCursor(connection=null) {
   this._description = null;
   this._rowcount = -1;
   this._connection = null;
   this._result = null;
   this._fields = null;
-  this.data = null;
+  this.data = [];
   this.fieldNames = null;
-  this.chandle = new CTaosInterface(null, true); //pass through, just need library loaded.
+  this._chandle = new CTaosInterface(null, true); //pass through, just need library loaded.
   if (connection != null) {
     this._connection = connection
   }
 
 }
+/**
+ * Get the description of the latest query
+ * @return {string} Description
+ */
 TDengineCursor.prototype.description = function description() {
   return this._description;
 }
+/**
+ * Get the row counts of the latest query
+ * @return {number} Rowcount
+ */
 TDengineCursor.prototype.rowcount = function rowcount() {
   return this._rowcount;
 }
 TDengineCursor.prototype.callproc = function callproc() {
   return;
 }
+/**
+ * Close the cursor by setting its connection to null and freeing results from the connection and resetting the results it has stored
+ * @return {boolean} Whether or not the cursor was succesfully closed
+ */
 TDengineCursor.prototype.close = function close() {
   if (this._connection == null) {
     return false;
   }
-  this._connection.clear_result_set();
+  this._connection._clearResultSet();
   this._reset_result();
   this._connection = null;
   return true;
 }
-TDengineCursor.prototype.execute = function execute(operation, params=null) {
+/**
+ *
+ * @return {TaosQuery} - A TaosQuery object
+ */
+TDengineCursor.prototype.query = function query(operation) {
+  return new TaosQuery(operation, this);
+}
+
+/**
+ * Execute a query. Also stores all the field names returned from the query into cursor.fieldNames;
+ * @param {string} operation -  The query operation to execute in the taos shell
+ * @param {number} verbose - A verbosity of 0 silences any logs from this function. A verbosity of 1 means this function will log query statues
+ * @return {number | buffer} Number of affected rows or a buffer that points to the results of the query
+ */
+TDengineCursor.prototype.execute = function execute(operation, verbose) {
   if (operation == undefined) {
     return null;
   }
   if (this._connection == null) {
     throw new errors.ProgrammingError('Cursor is not connected');
   }
-  this._connection.clear_result_set();
+  this._connection._clearResultSet();
   this._reset_result();
 
   let stmt = operation;
-  if (params != null) {
+  res = this._chandle.query(this._connection._conn, stmt);
-    //why pass?
-  }
-  res = this.chandle.query(this._connection._conn, stmt);
   if (res == 0) {
-    let fieldCount = this.chandle.fieldsCount(this._connection._conn);
+    let fieldCount = this._chandle.fieldsCount(this._connection._conn);
     if (fieldCount == 0) {
-      return this.chandle.affectedRows(this._connection._conn); //return num of affected rows, common with insert, use statements
+      let response = "Query OK"
+      return this._chandle.affectedRows(this._connection._conn); //return num of affected rows, common with insert, use statements
     }
     else {
-      let resAndField = this.chandle.useResult(this._connection._conn, fieldCount)
+      let resAndField = this._chandle.useResult(this._connection._conn, fieldCount)
       this._result = resAndField.result;
       this._fields = resAndField.fields;
       this.fieldNames = resAndField.fields.map(fieldData => fieldData.name);
-      return this._handle_result(); //return a pointer
+      return this._handle_result(); //return a pointer to the result
     }
   }
   else {
-    throw new errors.ProgrammingError(this.chandle.errStr(this._connection._conn))
+    throw new errors.ProgrammingError(this._chandle.errStr(this._connection._conn))
   }
 
-
 }
 TDengineCursor.prototype.executemany = function executemany() {
 
@@ -77,6 +109,15 @@ TDengineCursor.prototype.fetchone = function fetchone() {
 TDengineCursor.prototype.fetchmany = function fetchmany() {
 
 }
+/**
+ * Fetches all results from a query and also stores results into cursor.data
+ *
+ * @return {Array<Row>} The resultant array, with entries corresponding to each retreived row from the query results, sorted in
+ * order by the field name ordering in the table.
+ * @example
+ * cursor.execute('select * from db.table');
+ * var data = cursor.fetchall()
+ */
 TDengineCursor.prototype.fetchall = function fetchall() {
   if (this._result == null || this._fields == null) {
     throw new errors.OperationalError("Invalid use of fetchall, either result or fields from query are null");
@@ -86,7 +127,7 @@ TDengineCursor.prototype.fetchall = function fetchall() {
   let k = 0;
   while(true) {
     k+=1;
-    let blockAndRows = this.chandle.fetchBlock(this._result, this._fields);
+    let blockAndRows = this._chandle.fetchBlock(this._result, this._fields);
     let block = blockAndRows.blocks;
     let num_of_rows = blockAndRows.num_of_rows;
 
@@ -101,9 +142,9 @@ TDengineCursor.prototype.fetchall = function fetchall() {
       }
     }
   }
-  this._connection.clear_result_set();
+  this._connection._clearResultSet();
   this.data = data;
-  return data; //data[i]  returns the ith row, with all the data
+  return data;
 }
 TDengineCursor.prototype.nextset = function nextset() {
   return;
@@ -119,7 +160,7 @@ TDengineCursor.prototype._reset_result = function _reset_result() {
   this._rowcount = -1;
   this._result = null;
   this._fields = null;
-  this.data = null;
+  this.data = [];
   this.fieldNames = null;
 }
 TDengineCursor.prototype._handle_result = function _handle_result() {

src/connector/nodejs/nodetaos/taosquery.js

@@ -0,0 +1,52 @@
+module.exports = TaosQuery;
+
+
+/**
+ * Constructor for TaosQuery object
+ * @class TaosQuery
+ * @constructor
+ * @param {string} query - Query to construct object from
+ * @param {TDengineCursor} - The cursor from which this query will execute from
+ */
+function TaosQuery(query = "", cursor = null) {
+  this._query = query;
+  this._cursor = cursor;
+}
+
+/**
+ * Executes the query object and returns a Promise object
+ * @memberof TaosQuery
+ * @param {function} resultCallback - A callback function that takes the results as input
+ * @param {function} metaCallback - A callback function that takes the metadata or fields as input
+ * @return {Promise<results, fields>} A promise that evaluates into an object with keys "results" and "fields"
+ */
+TaosQuery.prototype.execute = async function execute(resultCallback, metaCallback) {
+  var taosQuery = this; //store the current instance of taosQuery to avoid async issues?
+  var executionPromise = new Promise(function(resolve, reject) {
+    let results = [];
+    try {
+      taosQuery._cursor.execute(taosQuery._query);
+      if (taosQuery._cursor._result != null){
+        results = taosQuery._cursor.fetchall();
+      }
+      if (metaCallback) metaCallback(taosQuery._cursor._fields);
+      if (resultCallback) resultCallback(results);
+    }
+    catch(err) {
+      reject(err);
+    }
+    resolve({results:results, fields:taosQuery._cursor._fields})
+
+  });
+  return executionPromise;
+}
+
+/**
+ *
+ * @param {...args} args - A
+ */
+TaosQuery.prototype.bind = function bind(...args) {
+  args.forEach(function(arg) {
+
+  });
+}

src/connector/nodejs/nodetaos/taosresult.js

@@ -0,0 +1,25 @@
+/**
+ * TaosResult
+ * @module TaosResult
+ */
+
+ module.exports = TaosResult;
+/**
+ * Constructor for a TaosResult object;
+ * @class TaosResult
+ * @constructor
+ * @param {Array<Row>} - Array of result rows
+ * @param {Array<Field>} - Array of field meta data
+ * @return {TaosResult}
+ */
+function TaosResult(result, fields) {
+  this.result = result;
+  this.rowcount = this.result.length;
+  this.fields = parseFields(fields);
+}
+
+TaosResult.prototype.parseFields = function parseFields(fields) {
+  fields.map(function(field) {
+    return {}
+  })
+}

src/connector/nodejs/readme.md

@@ -1,4 +1,6 @@
 # TDengine Node.js connector
+[![minzip](https://img.shields.io/bundlephobia/minzip/td-connector.svg)](https://github.com/taosdata/TDengine/tree/master/src/connector/nodejs) [![NPM](https://img.shields.io/npm/l/td-connector.svg)](https://github.com/taosdata/TDengine/#what-is-tdengine)
+
 This is the Node.js library that lets you connect to [TDengine](https://www.github.com/taosdata/tdengine).
 
 ## Installation
@@ -9,7 +11,7 @@ To get started, just type in the following to install the connector through [npm
 npm install td-connector
 ```
 
-To interact with TDengine, we make use of the [node-gyp[(https://github.com/nodejs/node-gyp)] library. To install, you will need to install the following depending on platform (the following instructions are quoted from node-gyp)
+To interact with TDengine, we make use of the [node-gyp](https://github.com/nodejs/node-gyp) library. To install, you will need to install the following depending on platform (the following instructions are quoted from node-gyp)
 
 ### On Unix