// NewFlagKeyValue implements the flag.Value interface for
// capturing ucfg.Config settings from command line arguments.
// Configuration options follow the argument name and must be in the form of
// "key=value". Using 'D' as command line flag for example, options on command line
// must be given as:
//
// -D key1=value -D key=value
//
// Note: the space between command line option and key is required by the flag
// package to parse command line flags correctly.
//
// Note: it's valid to use a key multiple times. If keys are used multiple
// times, values get overwritten. The last known value for some key will be stored
// in the generated configuration.
//
// The type of value must be any of bool, uint, int, float, or string. Any kind
// of array or object syntax is not supported.
//
// If autoBool is enabled (default if Config or ConfigVar is used), keys without
// value are converted to bool variable with value being true.
func NewFlagKeyValue(cfg *ucfg.Config, autoBool bool, opts ...ucfg.Option) *FlagValue {
return newFlagValue(cfg, opts, func(arg string) (*ucfg.Config, error, error) {
var key string
var val interface{}
var err error
args := strings.SplitN(arg, "=", 2)
if len(args) < 2 {
if !autoBool || len(args) == 0 {
err := fmt.Errorf("argument '%v' is empty ", arg)
return nil, err, err
}
key = arg
val = true
} else {
key = args[0]
val, err = parse.ParseValue(args[1])
if err != nil {
return nil, err, err
}
}
tmp := map[string]interface{}{key: val}
cfg, err := ucfg.NewFrom(tmp, opts...)
return cfg, err, err
})
}
func (s *cfgSplice) parseValue(opts *options) (value, error) {
str, err := s.splice.eval(s.ctx.getParent(), opts)
if err != nil {
return nil, err
}
ifc, err := parse.ParseValue(str)
if err != nil {
return nil, err
}
if ifc == nil {
if strings.TrimSpace(str) == "" {
return newString(s.ctx, s.meta(), str), nil
}
return &cfgNil{cfgPrimitive{ctx: s.ctx, metadata: s.meta()}}, nil
}
switch v := ifc.(type) {
case bool:
return newBool(s.ctx, s.meta(), v), nil
case int64:
return newInt(s.ctx, s.meta(), v), nil
case uint64:
return newUint(s.ctx, s.meta(), v), nil
case float64:
return newFloat(s.ctx, s.meta(), v), nil
case string:
return newString(s.ctx, s.meta(), v), nil
}
sub, err := normalize(opts, ifc)
if err != nil {
return nil, err
}
sub.ctx = s.ctx
sub.metadata = s.metadata
return cfgSub{sub}, nil
}