https://github.com/rakusan2/frc-nt-client
WPI NetworkTables Client for Node
https://github.com/rakusan2/frc-nt-client
frc javascript networktables
Last synced: 4 months ago
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WPI NetworkTables Client for Node
- Host: GitHub
- URL: https://github.com/rakusan2/frc-nt-client
- Owner: rakusan2
- License: mit
- Created: 2017-02-28T19:33:42.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2021-06-02T12:36:38.000Z (almost 4 years ago)
- Last Synced: 2025-01-31T00:07:34.290Z (4 months ago)
- Topics: frc, javascript, networktables
- Language: TypeScript
- Homepage: https://www.npmjs.com/package/wpilib-nt-client
- Size: 159 KB
- Stars: 21
- Watchers: 2
- Forks: 5
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# WPILIB Network Tables Client
This client uses version [3.0](https://github.com/wpilibsuite/ntcore/blob/master/doc/networktables3.adoc)
of the **Network Tables Protocol**. With a failover to [2.0](https://github.com/wpilibsuite/ntcore/blob/master/doc/networktables2.adoc)
## Installation
```
npm install wpilib-nt-client
```
## Usage
```js
// Decleration
const ntClient = require('wpilib-nt-client');
const client = new ntClient.Client()
// Connects the client to the server on team 3571's roborio
client.start((isConnected, err) => {
// Displays the error and the state of connection
console.log({ isConnected, err });
}, 'roborio-3571.local');
// Adds a listener to the client
client.addListener((key, val, type, id) => {
console.log({ key, val, type, id });
})
```
## Constructor
- `Client()`
- Standard Constructor
- `Client(options)`
- **options** an object containing is **strictInput** with a boolean value
- **strictInput** Does not try to correct incorrect types
## Properties
- `.start((connected, err, is2_0) => any, address, port)`
- Connects the client to a specific address and port
- **connected** - True if the client has successfully completed its handshake
- **err** - Contains the error if one has occurred
- **is2_0** - True if the client had to failover to 2.0 of the Network Tables protocol
- **address** - The address of the Server. Defaults to loopback
- **port** - The port of the server
- `.stop()`
- Tries to stop the client by sending a fin packet
- `.destroy()`
- Closes the connection forcefully
- `.setReconnectDelay(delay)`
- **delay** set the delay before trying to reconnect
- If the dellay is less than 20 than it wll not attempt reconnect
- `.addListener((key, value, valueType, type, id, flags) => any, getCurrent)`
- Adds a callback to be called when a value has been added, updated, or deleted, and returns the Listener
- **key** - The Key for the Entry
- **value** - The value associated with the key
- **valueType** - The type of the value Possible Types are listed Bellow
- **type** - The type of the callback. Possible Types are: "add", "update", "delete", "flagChange"
- **id** - The ID of the Entry
- **flags** - The flags of the Entry
- **getCurrent** - immediatly callback if connected with known entries
- `.removeListener(listener)`
- Removes the specified listener
- **listener** - The Listener returned from `.addListener()`
- `.isConnected()`
- Returns true if the client is connected and has completed its handshake
- `.uses2_0()`
- Returns true if the client has switched to using version 2.0 of the NetworkTables protocol
- `.getKeyID(key)`
- Returns the ID of a key or All of the keys if **key** is left out
- `.getEntry(id)`
- Returns an Entry identified with an ID
- `.Assign(val, name, persist)`
- Sets a new Entry
- **val** - The Value being added
- **name** - The Key for the Entry
- **persist** - An optional boolean value of whether the value shoud stay on the server after a restart
- Can return an error if type is an RPC
- `.Update(id, val)`
- **id** - The ID of the Entry to be updated
- **val** - The new Value
- Can Return an error if the Entry does not exist ot the value is of the wrong type
- `Flag(id, persist)`
- Updates the persist flag
- **id** - The ID of the Entry to be updated
- **persist** - An optional boolean value of whether the value shoud stay on the server after a restart
- Can return an error if the Entry does not exist
- `.Delete(id)`
- Deletes an Entry
- **id** - The ID of the entry being Deleted
- Can Return an error if the Entry does not exist
- `.DeleteAll()`
- Deletes all of the Entries
- Returns an error if the type is the client is using 2.0
- `.RPCExec(id, val, (result) => any)`
- Calls a Remote Procedure
- **id** - The ID of the procedure
- **val** - The Parameters of the Procedure
- **result** - The result of the call
- Can Return an error of parameter type does not corespond to the definition, the Entry is not an RPC, or the Entry does not Exist
- `.write(buf)`
- Sends a Message dirrectly to the server
- DO NOT USE unless you know what you are doing
## Types
- valueType
- Boolean
- Number
- String
- Buffer
- BooleanArray
- NumberArray
- StringArray
- RPC
- valueID
- 0x00 : "Boolean"
- 0x01 : "Number"
- 0x02 : "String"
- 0x03 : "Buffer"
- 0x10 : "BooleanArray"
- 0x11 : "NumberArray"
- 0x12 : "StringArray"
- 0x20 : "RPC"
## In 2.0
- Delete does not work
- Flags do not exist
- RPC does not exist
## RPC Entry Definition
Remote Procedure Call
```js
RPC:{
// The name of the Call
name,
// The parameters of the call
par:{
// The Id of the type of the parameter
typeId,
// The name of the Type of the parameter
typeName,
// Name of the Parameter
name,
// Default value for the parameter
default
}[],
// The format of the results
results:{
// The Id of the type of the result
typeId,
// The name of the Type of the result
typeName,
// The name of the result
name
}[]
}
```