path: root/Godeps/_workspace/src/github.com/codegangsta/cli/context.go

package cli

import (
    "errors"
    "flag"
    "strconv"
    "strings"
    "time"
)

// Context is a type that is passed through to
// each Handler action in a cli application. Context
// can be used to retrieve context-specific Args and
// parsed command-line options.
type Context struct {
    App            *App
    Command        Command
    flagSet        *flag.FlagSet
    globalSet      *flag.FlagSet
    setFlags       map[string]bool
    globalSetFlags map[string]bool
}

// Creates a new context. For use in when invoking an App or Command action.
func NewContext(app *App, set *flag.FlagSet, globalSet *flag.FlagSet) *Context {
    return &Context{App: app, flagSet: set, globalSet: globalSet}
}

// Looks up the value of a local int flag, returns 0 if no int flag exists
func (c *Context) Int(name string) int {
    return lookupInt(name, c.flagSet)
}

// Looks up the value of a local time.Duration flag, returns 0 if no time.Duration flag exists
func (c *Context) Duration(name string) time.Duration {
    return lookupDuration(name, c.flagSet)
}

// Looks up the value of a local float64 flag, returns 0 if no float64 flag exists
func (c *Context) Float64(name string) float64 {
    return lookupFloat64(name, c.flagSet)
}

// Looks up the value of a local bool flag, returns false if no bool flag exists
func (c *Context) Bool(name string) bool {
    return lookupBool(name, c.flagSet)
}

// Looks up the value of a local boolT flag, returns false if no bool flag exists
func (c *Context) BoolT(name string) bool {
    return lookupBoolT(name, c.flagSet)
}

// Looks up the value of a local string flag, returns "" if no string flag exists
func (c *Context) String(name string) string {
    return lookupString(name, c.flagSet)
}

// Looks up the value of a local string slice flag, returns nil if no string slice flag exists
func (c *Context) StringSlice(name string) []string {
    return lookupStringSlice(name, c.flagSet)
}

// Looks up the value of a local int slice flag, returns nil if no int slice flag exists
func (c *Context) IntSlice(name string) []int {
    return lookupIntSlice(name, c.flagSet)
}

// Looks up the value of a local generic flag, returns nil if no generic flag exists
func (c *Context) Generic(name string) interface{} {
    return lookupGeneric(name, c.flagSet)
}

// Looks up the value of a global int flag, returns 0 if no int flag exists
func (c *Context) GlobalInt(name string) int {
    return lookupInt(name, c.globalSet)
}

// Looks up the value of a global time.Duration flag, returns 0 if no time.Duration flag exists
func (c *Context) GlobalDuration(name string) time.Duration {
    return lookupDuration(name, c.globalSet)
}

// Looks up the value of a global bool flag, returns false if no bool flag exists
func (c *Context) GlobalBool(name string) bool {
    return lookupBool(name, c.globalSet)
}

// Looks up the value of a global string flag, returns "" if no string flag exists
func (c *Context) GlobalString(name string) string {
    return lookupString(name, c.globalSet)
}

// Looks up the value of a global string slice flag, returns nil if no string slice flag exists
func (c *Context) GlobalStringSlice(name string) []string {
    return lookupStringSlice(name, c.globalSet)
}

// Looks up the value of a global int slice flag, returns nil if no int slice flag exists
func (c *Context) GlobalIntSlice(name string) []int {
    return lookupIntSlice(name, c.globalSet)
}

// Looks up the value of a global generic flag, returns nil if no generic flag exists
func (c *Context) GlobalGeneric(name string) interface{} {
    return lookupGeneric(name, c.globalSet)
}

// Returns the number of flags set
func (c *Context) NumFlags() int {
    return c.flagSet.NFlag()
}

// Determines if the flag was actually set
func (c *Context) IsSet(name string) bool {
    if c.setFlags == nil {
        c.setFlags = make(map[string]bool)
        c.flagSet.Visit(func(f *flag.Flag) {
            c.setFlags[f.Name] = true
        })
    }
    return c.setFlags[name] == true
}

// Determines if the global flag was actually set
func (c *Context) GlobalIsSet(name string) bool {
    if c.globalSetFlags == nil {
        c.globalSetFlags = make(map[string]bool)
        c.globalSet.Visit(func(f *flag.Flag) {
            c.globalSetFlags[f.Name] = true
        })
    }
    return c.globalSetFlags[name] == true
}

// Returns a slice of flag names used in this context.
func (c *Context) FlagNames() (names []string) {
    for _, flag := range c.Command.Flags {
        name := strings.Split(flag.getName(), ",")[0]
        if name == "help" {
            continue
        }
        names = append(names, name)
    }
    return
}

// Returns a slice of global flag names used by the app.
func (c *Context) GlobalFlagNames() (names []string) {
    for _, flag := range c.App.Flags {
        name := strings.Split(flag.getName(), ",")[0]
        if name == "help" || name == "version" {
            continue
        }
        names = append(names, name)
    }
    return
}

type Args []string

// Returns the command line arguments associated with the context.
func (c *Context) Args() Args {
    args := Args(c.flagSet.Args())
    return args
}

// Returns the nth argument, or else a blank string
func (a Args) Get(n int) string {
    if len(a) > n {
        return a[n]
    }
    return ""
}

// Returns the first argument, or else a blank string
func (a Args) First() string {
    return a.Get(0)
}

// Return the rest of the arguments (not the first one)
// or else an empty string slice
func (a Args) Tail() []string {
    if len(a) >= 2 {
        return []string(a)[1:]
    }
    return []string{}
}

// Checks if there are any arguments present
func (a Args) Present() bool {
    return len(a) != 0
}

// Swaps arguments at the given indexes
func (a Args) Swap(from, to int) error {
    if from >= len(a) || to >= len(a) {
        return errors.New("index out of range")
    }
    a[from], a[to] = a[to], a[from]
    return nil
}

func lookupInt(name string, set *flag.FlagSet) int {
    f := set.Lookup(name)
    if f != nil {
        val, err := strconv.Atoi(f.Value.String())
        if err != nil {
            return 0
        }
        return val
    }

    return 0
}

func lookupDuration(name string, set *flag.FlagSet) time.Duration {
    f := set.Lookup(name)
    if f != nil {
        val, err := time.ParseDuration(f.Value.String())
        if err == nil {
            return val
        }
    }

    return 0
}

func lookupFloat64(name string, set *flag.FlagSet) float64 {
    f := set.Lookup(name)
    if f != nil {
        val, err := strconv.ParseFloat(f.Value.String(), 64)
        if err != nil {
            return 0
        }
        return val
    }

    return 0
}

func lookupString(name string, set *flag.FlagSet) string {
    f := set.Lookup(name)
    if f != nil {
        return f.Value.String()
    }

    return ""
}

func lookupStringSlice(name string, set *flag.FlagSet) []string {
    f := set.Lookup(name)
    if f != nil {
        return (f.Value.(*StringSlice)).Value()

    }

    return nil
}

func lookupIntSlice(name string, set *flag.FlagSet) []int {
    f := set.Lookup(name)
    if f != nil {
        return (f.Value.(*IntSlice)).Value()

    }

    return nil
}

func lookupGeneric(name string, set *flag.FlagSet) interface{} {
    f := set.Lookup(name)
    if f != nil {
        return f.Value
    }
    return nil
}

func lookupBool(name string, set *flag.FlagSet) bool {
    f := set.Lookup(name)
    if f != nil {
        val, err := strconv.ParseBool(f.Value.String())
        if err != nil {
            return false
        }
        return val
    }

    return false
}

func lookupBoolT(name string, set *flag.FlagSet) bool {
    f := set.Lookup(name)
    if f != nil {
        val, err := strconv.ParseBool(f.Value.String())
        if err != nil {
            return true
        }
        return val
    }

    return false
}

func copyFlag(name string, ff *flag.Flag, set *flag.FlagSet) {
    switch ff.Value.(type) {
    case *StringSlice:
    default:
        set.Set(name, ff.Value.String())
    }
}

func normalizeFlags(flags []Flag, set *flag.FlagSet) error {
    visited := make(map[string]bool)
    set.Visit(func(f *flag.Flag) {
        visited[f.Name] = true
    })
    for _, f := range flags {
        parts := strings.Split(f.getName(), ",")
        if len(parts) == 1 {
            continue
        }
        var ff *flag.Flag
        for _, name := range parts {
            name = strings.Trim(name, " ")
            if visited[name] {
                if ff != nil {
                    return errors.New("Cannot use two forms of the same flag: " + name + " " + ff.Name)
                }
                ff = set.Lookup(name)
            }
        }
        if ff == nil {
            continue
        }
        for _, name := range parts {
            name = strings.Trim(name, " ")
            if !visited[name] {
                copyFlag(name, ff, set)
            }
        }
    }
    return nil
}