forked from gliderlabs/sigil
/
sigil.go
131 lines (117 loc) · 2.54 KB
/
sigil.go
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package sigil
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"strings"
"text/template"
"github.com/mgood/go-posix"
)
var (
TemplatePath []string
PosixPreprocess bool
)
var leftDelim = "{{"
var rightDelim = "}}"
var fnMap = template.FuncMap{}
func init() {
delims := os.Getenv("SIGIL_DELIMS")
if delims != "" {
d := strings.Split(delims, ",")
leftDelim = d[0]
rightDelim = d[1]
}
}
type NamedReader struct {
io.Reader
Name string
}
func String(in interface{}) (string, string, bool) {
switch obj := in.(type) {
case string:
return obj, "", true
case NamedReader:
data, err := ioutil.ReadAll(obj)
if err != nil {
// TODO: better overall error/panic handling
panic(err)
}
return string(data), obj.Name, true
case fmt.Stringer:
return obj.String(), "", true
default:
return "", "", false
}
}
func Register(fm template.FuncMap) {
for k, v := range fm {
fnMap[k] = v
}
}
func PushPath(path string) {
TemplatePath = append([]string{path}, TemplatePath...)
}
func PopPath() {
_, TemplatePath = TemplatePath[0], TemplatePath[1:]
}
func LookPath(file string) (string, error) {
if strings.HasPrefix(file, "/") {
return file, nil
}
cwd, _ := os.Getwd()
search := append([]string{cwd}, TemplatePath...)
for _, path := range search {
filepath := filepath.Join(path, file)
if _, err := os.Stat(filepath); err == nil {
return filepath, nil
}
}
return "", fmt.Errorf("Not found in path: %s %v", file, TemplatePath)
}
func restoreEnv(env []string) {
os.Clearenv()
for _, kvp := range env {
kv := strings.SplitN(kvp, "=", 2)
os.Setenv(kv[0], kv[1])
}
}
func Execute(input []byte, vars map[string]interface{}, name string) (bytes.Buffer, error) {
var tmplVars string
var err error
defer restoreEnv(os.Environ())
for k, iv := range vars {
if v, ok := iv.(string); ok {
err := os.Setenv(k, v)
if err != nil {
return bytes.Buffer{}, err
}
}
tmplVars = tmplVars + fmt.Sprintf("%s $%s := .%s %s", leftDelim, k, k, rightDelim)
}
inputStr := string(input)
if PosixPreprocess {
inputStr, err = posix.ExpandEnv(inputStr)
if err != nil {
return bytes.Buffer{}, err
}
}
inputStr = strings.Replace(
inputStr,
fmt.Sprintf("\\%s\n%s", rightDelim, leftDelim),
fmt.Sprintf("%s%s", rightDelim, leftDelim),
-1,
)
tmpl, err := template.New(name).Funcs(fnMap).Delims(leftDelim, rightDelim).Parse(tmplVars + inputStr)
if err != nil {
return bytes.Buffer{}, err
}
var buf bytes.Buffer
err = tmpl.Execute(&buf, vars)
if err != nil {
return bytes.Buffer{}, err
}
return buf, nil
}