DockerCLI/templates/templates.go

97 lines
2.7 KiB
Go

package templates
import (
"bytes"
"encoding/json"
"strings"
"text/template"
)
// basicFunctions are the set of initial
// functions provided to every template.
var basicFunctions = template.FuncMap{
"json": func(v any) string {
buf := &bytes.Buffer{}
enc := json.NewEncoder(buf)
enc.SetEscapeHTML(false)
enc.Encode(v)
// Remove the trailing new line added by the encoder
return strings.TrimSpace(buf.String())
},
"split": strings.Split,
"join": strings.Join,
"title": strings.Title, //nolint:staticcheck // strings.Title is deprecated, but we only use it for ASCII, so replacing with golang.org/x/text is out of scope
"lower": strings.ToLower,
"upper": strings.ToUpper,
"pad": padWithSpace,
"truncate": truncateWithLength,
}
// HeaderFunctions are used to created headers of a table.
// This is a replacement of basicFunctions for header generation
// because we want the header to remain intact.
// Some functions like `pad` are not overridden (to preserve alignment
// with the columns).
var HeaderFunctions = template.FuncMap{
"json": func(v string) string {
return v
},
"split": func(v string, _ string) string {
// we want the table header to show the name of the column, and not
// split the table header itself. Using a different signature
// here, and return a string instead of []string
return v
},
"join": func(v string, _ string) string {
// table headers are always a string, so use a different signature
// for the "join" function (string instead of []string)
return v
},
"title": func(v string) string {
return v
},
"lower": func(v string) string {
return v
},
"upper": func(v string) string {
return v
},
"truncate": func(v string, _ int) string {
return v
},
}
// Parse creates a new anonymous template with the basic functions
// and parses the given format.
func Parse(format string) (*template.Template, error) {
return NewParse("", format)
}
// New creates a new empty template with the provided tag and built-in
// template functions.
func New(tag string) *template.Template {
return template.New(tag).Funcs(basicFunctions)
}
// NewParse creates a new tagged template with the basic functions
// and parses the given format.
func NewParse(tag, format string) (*template.Template, error) {
return New(tag).Parse(format)
}
// padWithSpace adds whitespace to the input if the input is non-empty
func padWithSpace(source string, prefix, suffix int) string {
if source == "" {
return source
}
return strings.Repeat(" ", prefix) + source + strings.Repeat(" ", suffix)
}
// truncateWithLength truncates the source string up to the length provided by the input
func truncateWithLength(source string, length int) string {
if len(source) < length {
return source
}
return source[:length]
}