QCommandLineConnection.h

/*
    File:       QCommandLineConnection.h

    Contains:   Manages a connection consisting of CR LF delimited lines.

    Written by: DTS

    Copyright:  Copyright (c) 2011 Apple Inc. All Rights Reserved.

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*/

#import "QCommandConnection.h"

// QCommandLineConnection is a subclass of QCommandConnection that managers 
// command-oriented network connection where the commands are lines of text, 
// each separated by a CR LF.
// 
// The class is run loop based and must be called from a single thread. 
// Specifically, the -open and -close methods add and remove run loop sources 
// to the current thread's run loop, and it's that thread that calls the 
// delegate callbacks.

@protocol QCommandLineConnectionDelegate;

@interface QCommandLineConnection : QCommandConnection

// Most of the heavy lifting is done by the QCommandConnection superclass.  The 
// following inherited methods are critical to all clients:
// 
// - (id)initWithInputStream:(NSInputStream *)inputStream outputStream:(NSOutputStream *)outputStream;
// - (void)open;
// - (void)close;

@property (nonatomic, assign, readwrite) id<QCommandLineConnectionDelegate> commandDelegate;

- (void)sendCommandLine:(NSString *)line;
    // Sends a single command line to the peer, adding CR LF to the end.
    
- (void)sendCommandLines:(NSArray *)lines;
    // Sends a list of command lines to the peer, adding CR LF after each.
    // lines must have at least one element.

@end

@protocol QCommandLineConnectionDelegate <NSObject>

@optional

- (void)commandLineConnection:(QCommandLineConnection *)connection willCloseWithError:(NSError *)error;
    // Called when the connection is closed from the network side of things (but not 
    // if you call -close on it).  You should implement this method to remove the connection 
    // from your table of active connections.
    //
    // error will be nil if the connection closed due to EOF; otherwise 
    // error will represent the reason for the close.

- (void)commandLineConnection:(QCommandLineConnection *)connection didReceiveCommandLine:(NSString *)commandLine;
    // Called when the connection receives a command line.  The command line will be CR LF 
    // terminated but may be empty.  If the command is unknown or malformed, the delegate 
    // can send an error response using -sendCommandLine:, or close the connection with 
    // -close, or both.

- (void)commandLineConnection:(QCommandLineConnection *)connection logWithFormat:(NSString *)format arguments:(va_list)argList;
    // Called when the connection wants to log something.

@end

// The following methods are exported for the benefit of subclasses.  Specifically, 
// they allow subclasses to see the delegate methods without actually being the 
// command delegate.  The default implementation of these routines just calls the 
// command delegate callback, if any, and then calls super (resulting in a call to the 
// connection delegate callback, if any).

@interface QCommandLineConnection (ForSubclassOverride)

- (void)willCloseWithError:(NSError *)error;

- (void)didReceiveCommandLine:(NSString *)commandLine;

- (void)logWithFormat:(NSString *)format arguments:(va_list)argList;

@end