abstract class util::AbstractMain
sys::Obj util::AbstractMain
AbstractMain provides conveniences for writing the main routine of an app. Command line arguments are configured as fields with the Arg
facet:
@Arg { help = "source file to process" } File? src
Arguments are ordered by the field declaration order. The last argument may be declared as a list to handle a variable numbers of arguments.
Command line options are configured as fields with the Opt
facet :
@Opt { help = "http port"; aliases=["p"] } Int port := 8080
Bool fields should always default to false and are considered flag options. All other arg and opt fields must be a Str, File, or have a type which supports a fromStr
method.
Option fields may include the "Opt" suffix, and arguments the "Arg" suffix. These suffixes can be used when a field conflicts with an existing slot name.
AbstractMain will automatically implement usage
and parseArgs
based on the fields which are declared as options and arguments. In general subclasses only need to override run
. If writing a daemon main, then you'll probably want to configure your services then call runServices
.
See example.
- appName
-
virtual Str appName()
Get the application name. If this is a script it is the name of the script file. For a precompiled class called "Main" this is the pod name, otherwise it is the type name.
- argFields
-
virtual Field[] argFields()
Get all the fields annotated with the
@Arg
facet. - helpOpt
-
@Opt { help="Print usage help"; aliases=["?"] }
Bool helpOpt := falsePrint usage help.
- homeDir
-
virtual File homeDir()
Home directory for the application. For a script this defaults to directory of the script. For pods the default is "{Env.cur.workDir}/etc/{pod}".
- log
-
virtual Log log()
Log for this application; defaults to
appName
. - main
-
virtual Int main(Str[] args := Env.cur().args())
Main performs the following tasks:
- optFields
-
virtual Field[] optFields()
Get all the fields annotated with the
@Opt
facet. - parseArgs
-
virtual Bool parseArgs(Str[] toks)
Parse the command line and set this instances fields. Return false if not all of the arguments were passed.
- printProps
-
static Void printProps(Str:Obj props, [Str:Obj]? opts := null)
Print a map of key/value pairs to output with values justified. Values that are lists are indented and separated by newlines. Options:
out
: OutStream to print to (default is Env.cur.out)indent
: Str spaces (default is "")
- run
-
abstract Int run()
Run the application. This method is called after the command line has been parsed. See
runServices
to launch a deamon application. Return status code, zero for success. - runServices
-
virtual Int runServices(Service[] services)
Run the set of services:
- call install on each service
- call start on each service
- put main thread to sleep.
- on shutodwn call stop on each service
- then call uninstall on each service
- runtimeProps
-
static Str:Obj runtimeProps([Str:Obj]? acc := null)
Get map of the standard runtime props including:
- java version info if JVM
- node version if running in NodeJS
- fan version Map vals are Strs or Lists to indent. Also see
printProps
- usage
-
virtual Int usage(OutStream out := Env.cur().out())
Print usage of arguments and options. Return non-zero.