5b121bc9fb
This patch enables developers to add one to many template functions that
can be used by custom Usage and Help templates. Here is an example that
is included in the file cobra_test.go as the test function named
TestAddTemplateFunctions:
AddTemplateFunc("t", func() bool { return true })
AddTemplateFuncs(template.FuncMap{
"f": func() bool { return false },
"h": func() string { return "Hello," },
"w": func() string { return "world." }})
const usage = "Hello, world."
c := &Command{}
c.SetUsageTemplate(`{{if t}}{{h}}{{end}}{{if f}}{{h}}{{end}} {{w}}`)
if us := c.UsageString(); us != usage {
t.Errorf("c.UsageString() != \"%s\", is \"%s\"", usage, us)
}
In the above example four functions are added to the template function
map used when the Usage and Help text is generated from the templates
that enable custom logic as well as data injection during template
execution.
129 lines
3.8 KiB
Go
129 lines
3.8 KiB
Go
// Copyright © 2013 Steve Francia <spf@spf13.com>.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
// Commands similar to git, go tools and other modern CLI tools
|
|
// inspired by go, go-Commander, gh and subcommand
|
|
|
|
package cobra
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"reflect"
|
|
"strconv"
|
|
"strings"
|
|
"text/template"
|
|
)
|
|
|
|
var templateFuncs template.FuncMap = template.FuncMap{
|
|
"trim": strings.TrimSpace,
|
|
"rpad": rpad,
|
|
"gt": Gt,
|
|
"eq": Eq,
|
|
}
|
|
|
|
var initializers []func()
|
|
|
|
// automatic prefix matching can be a dangerous thing to automatically enable in CLI tools.
|
|
// Set this to true to enable it
|
|
var EnablePrefixMatching bool = false
|
|
|
|
// enables an information splash screen on Windows if the CLI is started from explorer.exe.
|
|
var EnableWindowsMouseTrap bool = true
|
|
|
|
var MousetrapHelpText string = `This is a command line tool
|
|
|
|
You need to open cmd.exe and run it from there.
|
|
`
|
|
|
|
//AddTemplateFunc adds a template function that's available to Usage and Help
|
|
//template generation.
|
|
func AddTemplateFunc(name string, tmplFunc interface{}) {
|
|
templateFuncs[name] = tmplFunc
|
|
}
|
|
|
|
//AddTemplateFuncs adds multiple template functions availalble to Usage and
|
|
//Help template generation.
|
|
func AddTemplateFuncs(tmplFuncs template.FuncMap) {
|
|
for k, v := range tmplFuncs {
|
|
templateFuncs[k] = v
|
|
}
|
|
}
|
|
|
|
//OnInitialize takes a series of func() arguments and appends them to a slice of func().
|
|
func OnInitialize(y ...func()) {
|
|
for _, x := range y {
|
|
initializers = append(initializers, x)
|
|
}
|
|
}
|
|
|
|
//Gt takes two types and checks whether the first type is greater than the second. In case of types Arrays, Chans,
|
|
//Maps and Slices, Gt will compare their lengths. Ints are compared directly while strings are first parsed as
|
|
//ints and then compared.
|
|
func Gt(a interface{}, b interface{}) bool {
|
|
var left, right int64
|
|
av := reflect.ValueOf(a)
|
|
|
|
switch av.Kind() {
|
|
case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:
|
|
left = int64(av.Len())
|
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
|
left = av.Int()
|
|
case reflect.String:
|
|
left, _ = strconv.ParseInt(av.String(), 10, 64)
|
|
}
|
|
|
|
bv := reflect.ValueOf(b)
|
|
|
|
switch bv.Kind() {
|
|
case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:
|
|
right = int64(bv.Len())
|
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
|
right = bv.Int()
|
|
case reflect.String:
|
|
right, _ = strconv.ParseInt(bv.String(), 10, 64)
|
|
}
|
|
|
|
return left > right
|
|
}
|
|
|
|
//Eq takes two types and checks whether they are equal. Supported types are int and string. Unsupported types will panic.
|
|
func Eq(a interface{}, b interface{}) bool {
|
|
av := reflect.ValueOf(a)
|
|
bv := reflect.ValueOf(b)
|
|
|
|
switch av.Kind() {
|
|
case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:
|
|
panic("Eq called on unsupported type")
|
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
|
return av.Int() == bv.Int()
|
|
case reflect.String:
|
|
return av.String() == bv.String()
|
|
}
|
|
return false
|
|
}
|
|
|
|
//rpad adds padding to the right of a string
|
|
func rpad(s string, padding int) string {
|
|
template := fmt.Sprintf("%%-%ds", padding)
|
|
return fmt.Sprintf(template, s)
|
|
}
|
|
|
|
// tmpl executes the given template text on data, writing the result to w.
|
|
func tmpl(w io.Writer, text string, data interface{}) error {
|
|
t := template.New("top")
|
|
t.Funcs(templateFuncs)
|
|
template.Must(t.Parse(text))
|
|
return t.Execute(w, data)
|
|
}
|