Merge pull request #135 from akutz/feature/custom-templ-funcs

Template Function Injection
This commit is contained in:
Eric Paris 2015-09-01 11:55:58 -05:00
commit 1f92281ffc
2 changed files with 40 additions and 6 deletions

View file

@ -25,6 +25,13 @@ import (
"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.
@ -39,6 +46,20 @@ 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 {
@ -101,12 +122,7 @@ func rpad(s string, padding int) string {
// 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(template.FuncMap{
"trim": strings.TrimSpace,
"rpad": rpad,
"gt": Gt,
"eq": Eq,
})
t.Funcs(templateFuncs)
template.Must(t.Parse(text))
return t.Execute(w, data)
}

View file

@ -8,6 +8,7 @@ import (
"runtime"
"strings"
"testing"
"text/template"
"github.com/spf13/pflag"
)
@ -971,3 +972,20 @@ func TestFlagOnPflagCommandLine(t *testing.T) {
checkResultContains(t, r, flagName)
}
func TestAddTemplateFunctions(t *testing.T) {
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)
}
}