// Copyright 2015 Light Code Labs, LLC
//
// 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.
package markdown
import (
"bytes"
"io/ioutil"
"os"
"sync"
"text/template"
"github.com/mholt/caddy/caddyhttp/httpserver"
"github.com/mholt/caddy/caddyhttp/markdown/metadata"
)
// Data represents a markdown document.
type Data struct {
httpserver.Context
Doc map[string]interface{}
Styles []string
Scripts []string
Meta map[string]string
Files []FileInfo
}
// Include "overrides" the embedded httpserver.Context's Include()
// method so that included files have access to d's fields.
// Note: using {{template 'template-name' .}} instead might be better.
func (d Data) Include(filename string, args ...interface{}) (string, error) {
d.Args = args
return httpserver.ContextInclude(filename, d, d.Root)
}
var templateUpdateMu sync.RWMutex
// execTemplate executes a template given a requestPath, template, and metadata
func execTemplate(c *Config, mdata metadata.Metadata, meta map[string]string, files []FileInfo, ctx httpserver.Context) ([]byte, error) {
mdData := Data{
Context: ctx,
Doc: mdata.Variables,
Styles: c.Styles,
Scripts: c.Scripts,
Meta: meta,
Files: files,
}
templateName := mdata.Template
updateTemplate := func() error {
templateUpdateMu.Lock()
defer templateUpdateMu.Unlock()
templateFile, ok := c.TemplateFiles[templateName]
if !ok {
return nil
}
currentFileInfo, err := os.Lstat(templateFile.path)
if err != nil {
return err
}
if !fileChanged(currentFileInfo, templateFile.fi) {
return nil
}
// update template due to file changes
err = SetTemplate(c.Template, templateName, templateFile.path)
if err != nil {
return err
}
templateFile.fi = currentFileInfo
return nil
}
if err := updateTemplate(); err != nil {
return nil, err
}
b := new(bytes.Buffer)
templateUpdateMu.RLock()
defer templateUpdateMu.RUnlock()
if err := c.Template.ExecuteTemplate(b, templateName, mdData); err != nil {
return nil, err
}
return b.Bytes(), nil
}
func fileChanged(new, old os.FileInfo) bool {
// never checked before
if old == nil {
return true
}
if new.Size() != old.Size() ||
new.Mode() != old.Mode() ||
new.ModTime() != old.ModTime() {
return true
}
return false
}
// SetTemplate reads in the template with the filename provided. If the file does not exist or is not parsable, it will return an error.
func SetTemplate(t *template.Template, name, filename string) error {
// Read template
buf, err := ioutil.ReadFile(filename)
if err != nil {
return err
}
// Update if exists
if tt := t.Lookup(name); tt != nil {
_, err = tt.Parse(string(buf))
return err
}
// Allocate new name if not
_, err = t.New(name).Parse(string(buf))
return err
}
// GetDefaultTemplate returns the default template.
func GetDefaultTemplate() *template.Template {
return template.Must(template.New("").Parse(defaultTemplate))
}
const (
defaultTemplate = `<!DOCTYPE html>
<html>
<head>
<title>{{.Doc.title}}</title>
<meta charset="utf-8">
{{range $key, $val := .Meta}}
<meta name="{{$key}}" content="{{$val}}">
{{end}}
{{- range .Styles}}
<link rel="stylesheet" href="{{.}}">
{{- end}}
{{- range .Scripts}}
<script src="{{.}}"></script>
{{- end}}
</head>
<body>
{{.Doc.body}}
</body>
</html>`
)