map_string_bool.go

Documentation: k8s.io/component-base/cli/flag

     1  /*
     2  Copyright 2017 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package flag
    18  
    19  import (
    20  	"fmt"
    21  	"sort"
    22  	"strconv"
    23  	"strings"
    24  )
    25  
    26  // MapStringBool can be set from the command line with the format `--flag "string=bool"`.
    27  // Multiple comma-separated key-value pairs in a single invocation are supported. For example: `--flag "a=true,b=false"`.
    28  // Multiple flag invocations are supported. For example: `--flag "a=true" --flag "b=false"`.
    29  type MapStringBool struct {
    30  	Map         *map[string]bool
    31  	initialized bool
    32  }
    33  
    34  // NewMapStringBool takes a pointer to a map[string]string and returns the
    35  // MapStringBool flag parsing shim for that map
    36  func NewMapStringBool(m *map[string]bool) *MapStringBool {
    37  	return &MapStringBool{Map: m}
    38  }
    39  
    40  // String implements github.com/spf13/pflag.Value
    41  func (m *MapStringBool) String() string {
    42  	if m == nil || m.Map == nil {
    43  		return ""
    44  	}
    45  	pairs := []string{}
    46  	for k, v := range *m.Map {
    47  		pairs = append(pairs, fmt.Sprintf("%s=%t", k, v))
    48  	}
    49  	sort.Strings(pairs)
    50  	return strings.Join(pairs, ",")
    51  }
    52  
    53  // Set implements github.com/spf13/pflag.Value
    54  func (m *MapStringBool) Set(value string) error {
    55  	if m.Map == nil {
    56  		return fmt.Errorf("no target (nil pointer to map[string]bool)")
    57  	}
    58  	if !m.initialized || *m.Map == nil {
    59  		// clear default values, or allocate if no existing map
    60  		*m.Map = make(map[string]bool)
    61  		m.initialized = true
    62  	}
    63  	for _, s := range strings.Split(value, ",") {
    64  		if len(s) == 0 {
    65  			continue
    66  		}
    67  		arr := strings.SplitN(s, "=", 2)
    68  		if len(arr) != 2 {
    69  			return fmt.Errorf("malformed pair, expect string=bool")
    70  		}
    71  		k := strings.TrimSpace(arr[0])
    72  		v := strings.TrimSpace(arr[1])
    73  		boolValue, err := strconv.ParseBool(v)
    74  		if err != nil {
    75  			return fmt.Errorf("invalid value of %s: %s, err: %v", k, v, err)
    76  		}
    77  		(*m.Map)[k] = boolValue
    78  	}
    79  	return nil
    80  }
    81  
    82  // Type implements github.com/spf13/pflag.Value
    83  func (*MapStringBool) Type() string {
    84  	return "mapStringBool"
    85  }
    86  
    87  // Empty implements OmitEmpty
    88  func (m *MapStringBool) Empty() bool {
    89  	return len(*m.Map) == 0
    90  }
    91
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