Thrift Node.js Library
=========================

License
-------
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.

## Compatibility

Node.js 10.18 or later is required, matching the `engines` field in the
package's [`package.json`](../../package.json).

## Install

    npm install thrift 

## Thrift Compiler

You can compile IDL sources for Node.js with the following command:

    thrift --gen js:node thrift_file

## Cassandra Client Example:

Here is a Cassandra example:

```js
var thrift = require('thrift'),
    Cassandra = require('./gen-nodejs/Cassandra')
    ttypes = require('./gen-nodejs/cassandra_types');

var connection = thrift.createConnection("localhost", 9160),
    client = thrift.createClient(Cassandra, connection);

connection.on('error', function(err) {
  console.error(err);
});

client.get_slice("Keyspace", "key", new ttypes.ColumnParent({column_family: "ExampleCF"}), new ttypes.SlicePredicate({slice_range: new ttypes.SliceRange({start: '', finish: ''})}), ttypes.ConsistencyLevel.ONE, function(err, data) {
  if (err) {
    // handle err
  } else {
    // data == [ttypes.ColumnOrSuperColumn, ...]
  }
  connection.end();
});
```

<a name="int64"></a>
## Int64

Since JavaScript represents all numbers as doubles, int64 values cannot be accurately represented naturally. By default, both the protocol layer (`TBinaryProtocol.readI64()` etc.) and generated struct fields surface int64 values as [broofa/node-int64](https://github.com/broofa/node-int64) `Thrift.Int64` objects. See [BigInt mode](#bigint-mode-jsbigint-opt-in) below for the opt-in alternative — which changes only the generated-code field type and keeps the protocol layer unchanged.

### BigInt mode (`js:bigint`, opt-in)

Native `BigInt` has been available since Node 10.4, so every supported runtime
can use it. Pass `bigint` alongside `node` in the generator option list to
emit BigInt-aware code instead of `node-int64`:

```sh
thrift --gen js:node MyService.thrift           # default — node-int64 output
thrift --gen js:node,bigint MyService.thrift    # opt-in — native BigInt output
```

When the `bigint` flag is set, code generated by `--gen js:node` (and the
`ts`, `es6`, `esm` variants):

- Emits native `bigint` literals (e.g. `42n`, `9223372036854775807n`) for
  int64 constants instead of `new Int64(42)`.
- Drops the `require('node-int64')` / `import Int64 from 'node-int64'`
  preamble.
- Declares int64 fields as `bigint` in `.d.ts` files instead of `Int64`.
- Wraps `readI64()` calls with `thrift.toBigInt(...)` so deserialized
  fields land in the generated struct as `bigint`, and `writeI64(...)`
  calls with `thrift.fromBigInt(...)` so consumers can pass plain
  `bigint` values into their structs.

The flag is only meaningful when `node` is in the option list; passing
`bigint` to plain `--gen js` (browser JS) is silently ignored.

`TBinaryProtocol` itself is **unchanged** — `readI64` still returns a
`Thrift.Int64` and `writeI64` still expects one. The BigInt boundary lives
entirely in the JS layer, in the two helpers exported from the `thrift`
package:

```js
const thrift = require("thrift");

const big = thrift.toBigInt(prot.readI64());      // Int64  -> bigint
prot.writeI64(thrift.fromBigInt(big));            // bigint -> Int64
```

`thrift.fromBigInt` wraps values to the signed 64-bit range
(`BigInt.asIntN(64, ...)`) and accepts `bigint`, decimal-string, or `number`
input. Existing code that imports `Thrift.Int64` or calls `prot.readI64()`
directly keeps working with no changes.

## Client and server examples

Several example clients and servers are included in the thrift/lib/nodejs/examples folder and the cross language tutorial thrift/tutorial/nodejs folder.

## Use on browsers

You can use code generated with js:node on browsers with Webpack. Here is an example.

thrift --gen js:node,ts,es6,with_ns

```javascript
import * as thrift from 'thrift';
import { MyServiceClient } from '../gen-nodejs/MyService';

let host = window.location.hostname;
let port = 443;
let opts = {
  transport: thrift.TBufferedTransport,
  protocol: thrift.TJSONProtocol, 
    headers: {
     'Content-Type': 'application/vnd.apache.thrift.json',
    },
    https: true,
    path: '/url/path',
    useCORS: true,
};

let connection = thrift.createXHRConnection(host, port, opts);
let thriftClient = thrift.createXHRClient(MyServiceClient, connection);

connection.on('error', (err) => {
  console.error(err);
});

thriftClient.myService(param)
  .then((result) => {
    console.log(result);
  })
  .catch((err) => {
    ....
  });
```

Bundlers, like webpack, will use thrift/browser.js by default because of the 
`"browser": "./lib/nodejs/lib/thrift/browser.js"` field in package.json.

### Browser example with WebSocket, BufferedTransport and BinaryProtocol
```javascript
import thrift from 'thrift';
import { MyServiceClient } from '../gen-nodejs/MyService';

const host = window.location.hostname;
const port = 9090;
const opts = {
  transport: thrift.TBufferedTransport,
  protocol: thrift.TBinaryProtocol
}
const connection = thrift.createWSConnection(host, port, opts);
connection.open();
const thriftClient = thrift.createWSClient(MyServiceClient, connection);

connection.on('error', (err) => {
  console.error(err);
});

thriftClient.myService(param)
  .then((result) => {
    console.log(result);
  })
  .catch((err) => {
    ....
  });
```


