# Command-Option-Argument [![build status](https://secure.travis-ci.org/veged/coa.png)](http://travis-ci.org/veged/coa) ## What is it? COA is a parser for command line options that aim to get maximum profit from formalization your program API. Once you write definition in terms of commands, options and arguments you automaticaly get: * Command line help text * Program API for use COA-based programs as modules * Shell completion ### Other features * Rich types for options and arguments, such as arrays, boolean flags and required * Commands can be async throught using promising (powered by [Q](https://github.com/kriskowal/q)) * Easy submoduling some existing commands to new top-level one * Combined validation and complex parsing of values ### TODO * Localization * Shell-mode * Configs * Aliases * Defaults ## Examples ````javascript require('coa').Cmd() // main (top level) command declaration .name(process.argv[1]) // set top level command name from program name .title('My awesome command line util') // title for use in text messages .helpful() // make command "helpful", i.e. options -h --help with usage message .opt() // add some option .name('version') // name for use in API .title('Version') // title for use in text messages .short('v') // short key: -v .long('version') // long key: --version .flag() // for options without value .act(function(opts) { // add action for option // return message as result of action return JSON.parse(require('fs').readFileSync(__dirname + '/package.json')) .version; }) .end() // end option chain and return to main command .cmd().name('subcommand').apply(require('./subcommand').COA).end() // load subcommand from module .cmd() // inplace subcommand declaration .name('othercommand').title('Awesome other subcommand').helpful() .opt() .name('input').title('input file, required') .short('i').long('input') .val(function(v) { // validator function, also for translate simple values return require('fs').createReadStream(v) }) .req() // make option required .end() // end option chain and return to command .end() // end subcommand chain and return to parent command .run(process.argv.slice(2)); // parse and run on process.argv ```` ````javascript // subcommand.js exports.COA = function() { this .title('Awesome subcommand').helpful() .opt() .name('output').title('output file') .short('o').long('output') .output() // use default preset for "output" option declaration .end() }; ```` ## API reference ### Cmd Command is a top level entity. Commands may have options and arguments. #### Cmd.api Returns object containing all its subcommands as methods to use from other programs.
**@returns** *{Object}* #### Cmd.name Set a canonical command identifier to be used anywhere in the API.
**@param** *String* `_name` command name
**@returns** *COA.Cmd* `this` instance (for chainability) #### Cmd.title Set a long description for command to be used anywhere in text messages.
**@param** *String* `_title` command title
**@returns** *COA.Cmd* `this` instance (for chainability) #### Cmd.cmd Create new or add existing subcommand for current command.
**@param** *COA.Cmd* `[cmd]` existing command instance
**@returns** *COA.Cmd* new or added subcommand instance #### Cmd.opt Create option for current command.
**@returns** *COA.Opt* `new` option instance #### Cmd.arg Create argument for current command.
**@returns** *COA.Opt* `new` argument instance #### Cmd.act Add (or set) action for current command.
**@param** *Function* `act` action function, invoked in the context of command instance and has the parameters:
- *Object* `opts` parsed options
- *Array* `args` parsed arguments
- *Object* `res` actions result accumulator
It can return rejected promise by Cmd.reject (in case of error) or any other value treated as result.
**@param** *{Boolean}* [force=false] flag for set action instead add to existings
**@returns** *COA.Cmd* `this` instance (for chainability) #### Cmd.apply Apply function with arguments in context of command instance.
**@param** *Function* `fn`
**@param** *Array* `args`
**@returns** *COA.Cmd* `this` instance (for chainability) #### Cmd.comp Set custom additional completion for current command.
**@param** *Function* `fn` completion generation function, invoked in the context of command instance. Accepts parameters:
- *Object* `opts` completion options
It can return promise or any other value treated as result.
**@returns** *COA.Cmd* `this` instance (for chainability) #### Cmd.helpful Make command "helpful", i.e. add -h --help flags for print usage.
**@returns** *COA.Cmd* `this` instance (for chainability) #### Cmd.completable Adds shell completion to command, adds "completion" subcommand, that makes all the magic.
Must be called only on root command.
**@returns** *COA.Cmd* `this` instance (for chainability) #### Cmd.usage Build full usage text for current command instance.
**@returns** *String* `usage` text #### Cmd.run Parse arguments from simple format like NodeJS process.argv and run ahead current program, i.e. call process.exit when all actions done.
**@param** *Array* `argv`
**@returns** *COA.Cmd* `this` instance (for chainability) #### Cmd.invoke Invoke specified (or current) command using provided options and arguments.
**@param** *String|Array* `cmds` subcommand to invoke (optional)
**@param** *Object* `opts` command options (optional)
**@param** *Object* `args` command arguments (optional)
**@returns** *Q.Promise* #### Cmd.reject Return reject of actions results promise.
Use in .act() for return with error.
**@param** *Object* `reason` reject reason
You can customize toString() method and exitCode property of reason object.
**@returns** *Q.promise* rejected promise #### Cmd.end Finish chain for current subcommand and return parent command instance.
**@returns** *COA.Cmd* `parent` command ### Opt Option is a named entity. Options may have short and long keys for use from command line.
**@namespace**
**@class** Presents option #### Opt.name Set a canonical option identifier to be used anywhere in the API.
**@param** *String* `_name` option name
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.title Set a long description for option to be used anywhere in text messages.
**@param** *String* `_title` option title
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.short Set a short key for option to be used with one hyphen from command line.
**@param** *String* `_short`
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.long Set a short key for option to be used with double hyphens from command line.
**@param** *String* `_long`
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.flag Make an option boolean, i.e. option without value.
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.arr Makes an option accepts multiple values.
Otherwise, the value will be used by the latter passed.
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.req Makes an option req.
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.only Makes an option to act as a command, i.e. program will exit just after option action.
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.val Set a validation (or value) function for argument.
Value from command line passes through before becoming available from API.
Using for validation and convertion simple types to any values.
**@param** *Function* `_val` validating function, invoked in the context of option instance and has one parameter with value from command line
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.def Set a default value for option. Default value passed through validation function as ordinary value.
**@param** *Object* `_def`
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.input Make option value inputting stream. It's add useful validation and shortcut for STDIN. **@returns** *{COA.Opt}* `this` instance (for chainability) #### Opt.output Make option value outputing stream.
It's add useful validation and shortcut for STDOUT.
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.act Add action for current option command. This action is performed if the current option is present in parsed options (with any value).
**@param** *Function* `act` action function, invoked in the context of command instance and has the parameters:
- *Object* `opts` parsed options
- *Array* `args` parsed arguments
- *Object* `res` actions result accumulator
It can return rejected promise by Cmd.reject (in case of error) or any other value treated as result.
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.comp Set custom additional completion for current option.
**@param** *Function* `fn` completion generation function, invoked in the context of command instance. Accepts parameters:
- *Object* `opts` completion options
It can return promise or any other value treated as result.
**@returns** *COA.Opt* `this` instance (for chainability) #### Opt.end Finish chain for current option and return parent command instance.
**@returns** *COA.Cmd* `parent` command ### Arg Argument is a unnamed entity.
From command line arguments passed as list of unnamed values. #### Arg.name Set a canonical argument identifier to be used anywhere in text messages.
**@param** *String* `_name` argument name
**@returns** *COA.Arg* `this` instance (for chainability) #### Arg.title Set a long description for argument to be used anywhere in text messages.
**@param** *String* `_title` argument title
**@returns** *COA.Arg* `this` instance (for chainability) #### Arg.arr Makes an argument accepts multiple values.
Otherwise, the value will be used by the latter passed.
**@returns** *COA.Arg* `this` instance (for chainability) #### Arg.req Makes an argument req.
**@returns** *COA.Arg* `this` instance (for chainability) #### Arg.val Set a validation (or value) function for argument.
Value from command line passes through before becoming available from API.
Using for validation and convertion simple types to any values.
**@param** *Function* `_val` validating function, invoked in the context of argument instance and has one parameter with value from command line
**@returns** *COA.Arg* `this` instance (for chainability) #### Arg.def Set a default value for argument. Default value passed through validation function as ordinary value.
**@param** *Object* `_def`
**@returns** *COA.Arg* `this` instance (for chainability) #### Arg.output Make argument value outputing stream.
It's add useful validation and shortcut for STDOUT.
**@returns** *COA.Arg* `this` instance (for chainability) #### Arg.comp Set custom additional completion for current argument.
**@param** *Function* `fn` completion generation function, invoked in the context of command instance. Accepts parameters:
- *Object* `opts` completion options
It can return promise or any other value treated as result.
**@returns** *COA.Arg* `this` instance (for chainability) #### Arg.end Finish chain for current option and return parent command instance.
**@returns** *COA.Cmd* `parent` command