Documentation ¶
Overview ¶
Package joe contains a general purpose bot library inspired by Hubot.
Index ¶
- Constants
- type Adapter
- type Auth
- type Bot
- type Brain
- type CLIAdapter
- type Config
- type Error
- type Event
- type EventEmitter
- type InitEvent
- type Memory
- type MemoryEncoder
- type Message
- type Module
- type ModuleFunc
- type ReactionAwareAdapter
- type ReceiveMessageEvent
- type ShutdownEvent
- type Storage
- func (s *Storage) Close() error
- func (s *Storage) Delete(key string) (bool, error)
- func (s *Storage) Get(key string, value interface{}) (bool, error)
- func (s *Storage) Keys() ([]string, error)
- func (s *Storage) Set(key string, value interface{}) error
- func (s *Storage) SetMemory(m Memory)
- func (s *Storage) SetMemoryEncoder(enc MemoryEncoder)
- type User
- type UserTypingEvent
Constants ¶
const ErrNotAllowed = Error("not allowed")
ErrNotAllowed is returned if the user is not allowed access to a specific scope.
const ErrNotImplemented = Error("not implemented")
ErrNotImplemented is returned if the user tries to use a feature that is not implemented on the corresponding components (e.g. the Adapter). For instance, not all Adapter implementations may support emoji reactions and trying to attach a reaction to a message might return this error.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Adapter ¶
An Adapter connects the bot with the chat by enabling it to receive and send messages. Additionally advanced adapters can emit more events than just the ReceiveMessageEvent (e.g. the slack adapter also emits the UserTypingEvent). All adapter events must be setup in the RegisterAt function of the Adapter.
Joe provides a default CLIAdapter implementation which connects the bot with the local shell to receive messages from stdin and print messages to stdout.
type Auth ¶ added in v0.7.0
type Auth struct {
// contains filtered or unexported fields
}
Auth implements logic to add user authorization checks to your bot.
func (*Auth) CheckPermission ¶ added in v0.7.0
CheckPermission checks if a user has permissions to access a resource under a given scope. If the user is not permitted access this function returns ErrNotAllowed.
Scopes are interpreted in a hierarchical way where scope A can contain scope B if A is a prefix to B. For example, you can check if a user is allowed to read or write from the "Example" API by checking the "api.example.read" or "api.example.write" scope. When you grant the scope to a user you can now either decide only to grant the very specific "api.example.read" scope which means the user will not have write permissions or you can allow people write-only access via "api.example.write".
Alternatively you can also grant any access to the Example API via "api.example" which includes both the read and write scope beneath it. If you choose to, you could also allow even more general access to everything in the api via the "api" scope. The empty scope "" cannot be granted and will thus always return an error in the permission check.
func (*Auth) Grant ¶ added in v0.7.0
Grant adds a permission scope to the given user. When a scope was granted to a specific user it can be checked later via CheckPermission(…). The returned boolean indicates whether the scope was actually added (i.e. true) or the user already had the granted scope (false).
Note that granting a scope is an idempotent operations so granting the same scope multiple times is a safe operation and will not change the internal permissions that are written to the Memory.
The empty scope cannot be granted and trying to do so will result in an error. If you want to grant access to all scopes you should prefix them with a common scope such as "root." or "api.".
func (*Auth) Revoke ¶ added in v0.8.0
Revoke removes a previously granted permission from a user. If the user does not currently have the revoked scope this function returns false and no error.
If you are trying to revoke a permission but the user was previously granted a scope that contains the revoked scope this function returns an error.
func (*Auth) UserPermissions ¶ added in v0.9.0
UserPermissions returns all permission scopes for a specific user.
type Bot ¶
type Bot struct { Name string Adapter Adapter Brain *Brain Store *Storage Auth *Auth Logger *zap.Logger // contains filtered or unexported fields }
A Bot represents an event based chat bot. For the most simple usage you can use the Bot.Respond(…) function to make the bot execute a function when it receives a message that matches a given pattern.
More advanced usage includes persisting memory or emitting your own events using the Brain of the robot.
func New ¶
New creates a new Bot and initializes it with the given Modules and Options. By default the Bot will use an in-memory Storage and a CLI adapter that reads messages from stdin and writes to stdout.
The modules can be used to change the Memory or Adapter or register other new functionality. Additionally you can pass Options which allow setting some simple configuration such as the event handler timeouts or injecting a different context. All Options are available as functions in this package that start with "With…".
If there was an error initializing a Module it is stored and returned on the next call to Bot.Run(). Before you start the bot however you should register your custom event handlers.
Example:
b := joe.New("example", redis.Memory("localhost:6379"), slack.Adapter("xoxb-58942365423-…"), joehttp.Server(":8080"), joe.WithHandlerTimeout(time.Second), ) b.Respond("ping", b.Pong) b.Brain.RegisterHandler(b.Init) err := b.Run() …
func (*Bot) Respond ¶
Respond registers an event handler that listens for the ReceiveMessageEvent and executes the given function only if the message text matches the given message. The message will be matched against the msg string as regular expression that must match the entire message in a case insensitive way.
You can use sub matches in the msg which will be passed to the function via Message.Matches.
If you need complete control over the regular expression, e.g. because you want the patter to match only a substring of the message but not all of it, you can use Bot.RespondRegex(…).
func (*Bot) RespondRegex ¶
RespondRegex is like Bot.Respond(…) but gives a little more control over the regular expression. However, also with this function messages are matched in a case insensitive way.
type Brain ¶
type Brain struct {
// contains filtered or unexported fields
}
The Brain contains the core logic of a Bot by implementing an event handling system that dispatches events to all registered event handlers.
func NewBrain ¶
NewBrain creates a new robot Brain. If the passed logger is nil it will fallback to the zap.NewNop() logger.
func (*Brain) Emit ¶
Emit sends the first argument as event to the brain from where it is dispatched to all registered handlers. The events are dispatched asynchronously but in the same order in which they are send to this function. Emit does not block until the event is delivered to the registered event handlers. If you want to wait until all handlers have processed the event you can pass one or more callback functions that will be executed when all handlers finished execution of this event.
func (*Brain) HandleEvents ¶
func (b *Brain) HandleEvents()
HandleEvents starts the event handling loop of the Brain. This function blocks until Brain.Shutdown() is called and returned.
func (*Brain) RegisterHandler ¶
func (b *Brain) RegisterHandler(fun interface{})
RegisterHandler registers a function to be executed when a specific event is fired. The function signature must comply with the following rules or the bot that uses this Brain will return an error on its next Bot.Run() call:
Allowed function signatures:
// MyCustomEventStruct must be any struct but not a pointer to a struct. func(MyCustomEventStruct) // You can optionally accept a context as the first argument. The context // is used to signal handler timeouts or when the bot is shutting down. func(context.Context, MyCustomEventStruct) // You can optionally return a single error value. Returning any other type // or returning more than one value will lead to an error. If the handler // returns an error it will be logged. func(MyCustomEventStruct) error // Event handlers can also accept an interface in which case they will be // be called for all events which implement the interface. Consequently, // you can register a function which accepts the empty interface which will // will receive all emitted events. Such event handlers can optionally also // accept a context and/or return an error like other handlers. func(context.Context, interface{}) error
The event that will be dispatched to the passed handler function corresponds directly to the accepted function argument. For instance if you want to emit and receive a custom event you can implement it like this:
type CustomEvent struct {} b := NewBrain(nil) b.RegisterHandler(func(evt CustomEvent) { … })
func (*Brain) Shutdown ¶ added in v0.2.0
Shutdown stops the event handler loop of the Brain and waits until all pending events have been processed. After the brain is shutdown, it will no longer accept new events. The passed context can be used to stop waiting for any pending events or handlers and instead exit immediately (e.g. after a timeout or a second SIGTERM).
type CLIAdapter ¶
type CLIAdapter struct { Prefix string Input io.ReadCloser Output io.Writer Logger *zap.Logger Author string // used to set the author of the messages, defaults to os.Getenv("USER) // contains filtered or unexported fields }
The CLIAdapter is the default Adapter implementation that the bot uses if no other adapter was configured. It emits a ReceiveMessageEvent for each line it receives from stdin and prints all sent messages to stdout.
The CLIAdapter does not set the Message.Data field.
func NewCLIAdapter ¶
func NewCLIAdapter(name string, logger *zap.Logger) *CLIAdapter
NewCLIAdapter creates a new CLIAdapter. The caller must call Close to make the CLIAdapter stop reading messages and emitting events.
func (*CLIAdapter) Close ¶
func (a *CLIAdapter) Close() error
Close makes the CLIAdapter stop emitting any new events or printing any output. Calling this function more than once will result in an error.
func (*CLIAdapter) React ¶ added in v0.9.0
func (a *CLIAdapter) React(r reactions.Reaction, _ Message) error
React implements the optional ReactionAwareAdapter interface by simply printing the given reaction as UTF8 emoji to the CLI.
func (*CLIAdapter) RegisterAt ¶ added in v0.2.0
func (a *CLIAdapter) RegisterAt(brain *Brain)
RegisterAt starts the CLIAdapter by reading messages from stdin and emitting a ReceiveMessageEvent for each of them. Additionally the adapter hooks into the InitEvent to print a nice prefix to stdout to show to the user it is ready to accept input.
func (*CLIAdapter) Send ¶
func (a *CLIAdapter) Send(text, channel string) error
Send implements the Adapter interface by sending the given text to stdout. The channel argument is required by the Adapter interface but is otherwise ignored.
type Config ¶
type Config struct { Context context.Context Name string HandlerTimeout time.Duration // contains filtered or unexported fields }
Config is the configuration of a Bot that can be used or changed during setup in a Module. Some configuration settings such as the Logger are read only can only be accessed via the corresponding getter function of the Config.
func NewConfig ¶ added in v0.6.0
NewConfig creates a new Config that is used to setup the underlying components of a Bot. For the typical use case you do not have to create a Config yourself but rather configure a Bot by passing the corresponding Modules to joe.New(…).
func (*Config) EventEmitter ¶
func (c *Config) EventEmitter() EventEmitter
EventEmitter returns the EventEmitter that can be used to send events to the Bot and other modules.
func (*Config) RegisterHandler ¶
func (c *Config) RegisterHandler(fun interface{})
RegisterHandler can be used to register an event handler in a Module.
func (*Config) SetAdapter ¶
SetAdapter can be used to change the Adapter implementation of the Bot.
func (*Config) SetMemoryEncoder ¶ added in v0.8.0
func (c *Config) SetMemoryEncoder(enc MemoryEncoder)
SetMemoryEncoder can be used to change the MemoryEncoder implementation of the bot.
type Error ¶ added in v0.7.0
type Error string
Error is the error type used by Joe. This allows joe errors to be defined as constants following https://dave.cheney.net/2016/04/07/constant-errors.
type Event ¶
type Event struct { Data interface{} Callbacks []func(Event) }
An Event represents a concrete event type and optional callbacks that are triggered when the event was processed by all registered handlers.
type EventEmitter ¶
type EventEmitter interface {
Emit(event interface{}, callbacks ...func(Event))
}
The EventEmitter can be used by a Module by calling Config.EventEmitter(). Events are emitted asynchronously so every call to Emit is non-blocking.
type InitEvent ¶
type InitEvent struct{}
The InitEvent is the first event that is handled by the Brain after the Bot is started via Bot.Run().
type Memory ¶
type Memory interface { Set(key string, value []byte) error Get(key string) ([]byte, bool, error) Delete(key string) (bool, error) Keys() ([]string, error) Close() error }
The Memory interface allows the bot to persist data as key-value pairs. The default implementation of the Memory is to store all keys and values in a map (i.e. in-memory). Other implementations typically offer actual long term persistence into a file or to redis.
type MemoryEncoder ¶ added in v0.8.0
type MemoryEncoder interface { Encode(value interface{}) ([]byte, error) Decode(data []byte, target interface{}) error }
A MemoryEncoder is used to encode and decode any values that are stored in the Memory. The default implementation that is used by the Storage uses a JSON encoding.
type Message ¶
type Message struct { Context context.Context ID string // The ID of the message, identifying it at least uniquely within the Channel Text string AuthorID string Channel string Matches []string // contains all sub matches of the regular expression that matched the Text Data interface{} // corresponds to the ReceiveMessageEvent.Data field // contains filtered or unexported fields }
A Message is automatically created from a ReceiveMessageEvent and then passed to the RespondFunc that was registered via Bot.Respond(…) or Bot.RespondRegex(…) when the message matches the regular expression of the handler.
func (*Message) React ¶ added in v0.9.0
React attempts to let the Adapter attach the given reaction to this message. If the adapter does not support this feature this function will return ErrNotImplemented.
type Module ¶
A Module is an optional Bot extension that can add new capabilities such as a different Memory implementation or Adapter.
func WithContext ¶
WithContext is an option to replace the default context of a bot.
func WithHandlerTimeout ¶
WithHandlerTimeout is an option to set a timeout on event handlers functions. By default no timeout is enforced.
func WithLogger ¶ added in v0.3.0
WithLogger is an option to replace the default logger of a bot.
type ModuleFunc ¶ added in v0.4.0
ModuleFunc is a function implementation of a Module.
func (ModuleFunc) Apply ¶ added in v0.4.0
func (f ModuleFunc) Apply(conf *Config) error
Apply implements the Module interface.
type ReactionAwareAdapter ¶ added in v0.9.0
ReactionAwareAdapter is an optional interface that Adapters can implement if they support reacting to messages with emojis.
type ReceiveMessageEvent ¶
type ReceiveMessageEvent struct { ID string // The ID of the message, identifying it at least uniquely within the Channel Text string // The message text. AuthorID string // A string identifying the author of the message on the adapter. Channel string // The channel over which the message was received. // A message may optionally also contain additional information that was // received by the Adapter (e.g. with the slack adapter this may be the // *slack.MessageEvent. Each Adapter implementation should document if and // what information is available here, if any at all. Data interface{} }
The ReceiveMessageEvent is typically emitted by an Adapter when the Bot sees a new message from the chat.
type ShutdownEvent ¶
type ShutdownEvent struct{}
The ShutdownEvent is the last event that is handled by the Brain before it stops handling any events after the bot context is done.
type Storage ¶ added in v0.8.0
type Storage struct {
// contains filtered or unexported fields
}
A Storage provides a convenient interface to a Memory implementation. It is responsible for how the actual key value data is encoded and provides concurrent access as well as logging.
The default Storage that is returned by joe.NewStorage() encodes values as JSON and stores them in-memory.
func NewStorage ¶ added in v0.8.0
NewStorage creates a new Storage instance that encodes values as JSON and stores them in-memory. You can change the memory and encoding via the provided setters.
func (*Storage) Delete ¶ added in v0.8.0
Delete removes a key and its associated value from the memory. The boolean return value indicates if the key existed or not.
func (*Storage) Get ¶ added in v0.8.0
Get retrieves the value under the requested key and decodes it into the passed "value" argument which must be a pointer. The boolean return value indicates if the value actually existed in the Memory and is false if it did not. It is legal to pass <nil> as the value if you only want to check if the given key exists but you do not actually care about the concrete value.
func (*Storage) Set ¶ added in v0.8.0
Set encodes the given data and stores it in the Memory that is managed by the Storage.
func (*Storage) SetMemoryEncoder ¶ added in v0.8.0
func (s *Storage) SetMemoryEncoder(enc MemoryEncoder)
SetMemoryEncoder assigns a different MemoryEncoder.
type UserTypingEvent ¶
The UserTypingEvent is emitted by the Adapter and indicates that the Bot sees that a user is typing. This event may not be emitted on all Adapter implementations but only when it is actually supported (e.g. on slack).
Source Files ¶
Directories ¶
Path | Synopsis |
---|---|
Package joetest implements helpers to implement unit tests for bots.
|
Package joetest implements helpers to implement unit tests for bots. |
Package reactions contains a list of generated reactions that are widely used in different chat applications on the internet.
|
Package reactions contains a list of generated reactions that are widely used in different chat applications on the internet. |