cliflagutils

README

cliflagutils

cliflagutils makes it easier to process CLI options for complex XML apps.

Documentation

Overview

Package cliflagutils provides a generic command line argument processing capability for XML-oriented programs. It provides a large set of useful arguments that can be individually (or as a group) enabled or disabled (i.e. hidden).

The package imports github.com/fbaube/(fileutils,stringutils,wasmutils)

Index

• Variables
• func CheckMustUsage() error
• func DisableAllFlags()
• func DisableFlags(s string)
• func EnableAllFlags()
• func EnableFlags(s string)
• func EnvarNameFromFlagName(s string) string
• func FlagNameFromEnvarName(s string) string
• func HasFlag(haystack []string, needle string) bool
• func MyUsage()
• func ParseEnvars() error
• type GCtx
• type XmlAppConfiguration
  • func GetXmlAppConfiguration() *XmlAppConfiguration
  • func NewXmlAppConfiguration(osArgs []string) (*XmlAppConfiguration, error)

Variables

var UMM = map[string]string{

	"h": "Show extended help message and exit",
	"g": "Group all generated files in same-named folder \n" +
		"(e.g. ./Filenam.xml maps to ./Filenam.xml_gxml/Filenam.*)",
	"m": "Import input file(s) to database",
	"p": "Pretty-print to file with \"fmtd-\" prepended to file extension",
	"t": "gTree written to file with \"gtr-\" prepended to file extension",
	"k": "gTokens written to file with \"gtk-\" prepended to file extension",
	"v": "Validate input file(s) (using xmllint) (with flag \"-c\" or \"-s\")",
	"z": "Zero out the database",
	"D": "Turn on debugging",
	"L": "Follow symbolic links in directory recursion",

	"c": "XML `catalog_filepath` (do not use with \"-s\" flag)",
	"o": "`output_filepath` (possibly ignored, depending on command)",
	"d": "Database mmmc.db `directory_path`",
	"r": "Run REST server on `port_number`",
	"s": "DTD schema file(s) `directory_path` (.dtd, .mod)",
}

UMM is the Usage Message Map. We do this to provide (here) a quick option reference, and (below) to make the actual code clearer. e.g. commits := map[string]int { "rsc": 3711, "r": 2138, }

Functions

func CheckMustUsage

func CheckMustUsage() error

CheckMustUsage returns a non-nil loggable error message if the caller should abort execution.

func DisableAllFlags

func DisableAllFlags()

func DisableFlags

func DisableFlags(s string)

func EnableAllFlags

func EnableAllFlags()

func EnableFlags

func EnableFlags(s string)

func EnvarNameFromFlagName

func EnvarNameFromFlagName(s string) string

func FlagNameFromEnvarName

func FlagNameFromEnvarName(s string) string

func HasFlag

func HasFlag(haystack []string, needle string) bool

func MyUsage

func MyUsage()

MyUsage displays (1) the app name (or "(wasm)"), plus (2) a usage summary (see the func body), plus (3) the flags' usage message. TODO: Should not return info for flags that are Hidden (i.e. disabled).

func ParseEnvars

func ParseEnvars() error

ParseEnvars is based on https://scene-si.org/2020/04/28/extending-pflag-with-environment-variables/

Types

type GCtx

type GCtx struct {
	// Context, used mainly for cancellation
	context.Context // = context.Context.TODO
	// Database connection
	*sqlx.DB
	// Database transaction
	*sqlx.Tx
	// XML configuration
	*XmlAppConfiguration
	// OwnLogPfx is own log prefix (should include a blank if needed)
	OwnLogPfx string
}

GCtx carries background info thru a thread or goroutine. Golang best practices for `Context` say that 1) It should not be embedded anywhere, but rather should be passed as the first argument to func calls, and 2) It should contain only request-scoped data. But we won't abide by those rules for Context because 1) We only use it for cancellation, and 2) We want zero-argument method calls, and 3) We also store data that is NOT request-scoped.

type XmlAppConfiguration

type XmlAppConfiguration struct {
	AppName  string
	DBhandle *DU.MmmcDB
	Infile, Outfile, Dbdir,
	Xmlcatfile, Xmlschemasdir FU.PathProps // NOT ptr! Barfs at startup.
	RestPort int
	// CLI flags
	FollowSymLinks, Pritt, DBdoImport, Help, Debug,
	GroupGenerated, GTokens, GTree, Validate, DBdoZeroOut bool
	// Result of processing CLI arg for input file(s)
	SingleFile bool
	// Result of processing CLI args (-c, -s)
	*XU.XmlCatalogFile
	PrittOutput io.Writer
	// contains filtered or unexported fields
}

XmlAppConfiguration can probably be used with various 3rd-party utilities.

func GetXmlAppConfiguration

func GetXmlAppConfiguration() *XmlAppConfiguration

func NewXmlAppConfiguration

func NewXmlAppConfiguration(osArgs []string) (*XmlAppConfiguration, error)

NewXmlAppConfiguration processes CLI arguments for any XML-related command. It takes the CLI arguments as calling parameters, rather than accessing them directly itself, to facilitate testing, and enable running in-browser as wasm.