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gitea/vendor/github.com/unrolled/render/render.go

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package render
import (
"bytes"
"fmt"
"html/template"
"io"
"log"
"net/http"
"os"
"path/filepath"
"strings"
"sync"
"github.com/fsnotify/fsnotify"
)
const (
// ContentBinary header value for binary data.
ContentBinary = "application/octet-stream"
// ContentHTML header value for HTML data.
ContentHTML = "text/html"
// ContentJSON header value for JSON data.
ContentJSON = "application/json"
// ContentJSONP header value for JSONP data.
ContentJSONP = "application/javascript"
// ContentLength header constant.
ContentLength = "Content-Length"
// ContentText header value for Text data.
ContentText = "text/plain"
// ContentType header constant.
ContentType = "Content-Type"
// ContentXHTML header value for XHTML data.
ContentXHTML = "application/xhtml+xml"
// ContentXML header value for XML data.
ContentXML = "text/xml"
// Default character encoding.
defaultCharset = "UTF-8"
)
// helperFuncs had to be moved out. See helpers.go|helpers_pre16.go files.
// Delims represents a set of Left and Right delimiters for HTML template rendering.
type Delims struct {
// Left delimiter, defaults to {{.
Left string
// Right delimiter, defaults to }}.
Right string
}
// Options is a struct for specifying configuration options for the render.Render object.
type Options struct {
// Directory to load templates. Default is "templates".
Directory string
// FileSystem to access files
FileSystem FileSystem
// Asset function to use in place of directory. Defaults to nil.
Asset func(name string) ([]byte, error)
// AssetNames function to use in place of directory. Defaults to nil.
AssetNames func() []string
// Layout template name. Will not render a layout if blank (""). Defaults to blank ("").
Layout string
// Extensions to parse template files from. Defaults to [".tmpl"].
Extensions []string
// Funcs is a slice of FuncMaps to apply to the template upon compilation. This is useful for helper functions. Defaults to empty map.
Funcs []template.FuncMap
// Delims sets the action delimiters to the specified strings in the Delims struct.
Delims Delims
// Appends the given character set to the Content-Type header. Default is "UTF-8".
Charset string
// If DisableCharset is set to true, it will not append the above Charset value to the Content-Type header. Default is false.
DisableCharset bool
// Outputs human readable JSON.
IndentJSON bool
// Outputs human readable XML. Default is false.
IndentXML bool
// Prefixes the JSON output with the given bytes. Default is false.
PrefixJSON []byte
// Prefixes the XML output with the given bytes.
PrefixXML []byte
// Allows changing the binary content type.
BinaryContentType string
// Allows changing the HTML content type.
HTMLContentType string
// Allows changing the JSON content type.
JSONContentType string
// Allows changing the JSONP content type.
JSONPContentType string
// Allows changing the Text content type.
TextContentType string
// Allows changing the XML content type.
XMLContentType string
// If IsDevelopment is set to true, this will recompile the templates on every request. Default is false.
IsDevelopment bool
// If UseMutexLock is set to true, the standard `sync.RWMutex` lock will be used instead of the lock free implementation. Default is false.
// Note that when `IsDevelopment` is true, the standard `sync.RWMutex` lock is always used. Lock free is only a production feature.
UseMutexLock bool
// Unescape HTML characters "&<>" to their original values. Default is false.
UnEscapeHTML bool
// Streams JSON responses instead of marshalling prior to sending. Default is false.
StreamingJSON bool
// Require that all partials executed in the layout are implemented in all templates using the layout. Default is false.
RequirePartials bool
// Deprecated: Use the above `RequirePartials` instead of this. As of Go 1.6, blocks are built in. Default is false.
RequireBlocks bool
// Disables automatic rendering of http.StatusInternalServerError when an error occurs. Default is false.
DisableHTTPErrorRendering bool
// Enables using partials without the current filename suffix which allows use of the same template in multiple files. e.g {{ partial "carosuel" }} inside the home template will match carosel-home or carosel.
// ***NOTE*** - This option should be named RenderPartialsWithoutSuffix as that is what it does. "Prefix" is a typo. Maintaining the existing name for backwards compatibility.
RenderPartialsWithoutPrefix bool
// BufferPool to use when rendering HTML templates. If none is supplied
// defaults to SizedBufferPool of size 32 with 512KiB buffers.
BufferPool GenericBufferPool
}
// HTMLOptions is a struct for overriding some rendering Options for specific HTML call.
type HTMLOptions struct {
// Layout template name. Overrides Options.Layout.
Layout string
// Funcs added to Options.Funcs.
Funcs template.FuncMap
}
// Render is a service that provides functions for easily writing JSON, XML,
// binary data, and HTML templates out to a HTTP Response.
type Render struct {
lock rwLock
// Customize Secure with an Options struct.
opt Options
templates *template.Template
compiledCharset string
hasWatcher bool
}
// New constructs a new Render instance with the supplied options.
func New(options ...Options) *Render {
var o Options
if len(options) > 0 {
o = options[0]
}
r := Render{opt: o}
r.prepareOptions()
r.CompileTemplates()
return &r
}
func (r *Render) prepareOptions() {
// Fill in the defaults if need be.
if len(r.opt.Charset) == 0 {
r.opt.Charset = defaultCharset
}
if !r.opt.DisableCharset {
r.compiledCharset = "; charset=" + r.opt.Charset
}
if len(r.opt.Directory) == 0 {
r.opt.Directory = "templates"
}
if r.opt.FileSystem == nil {
r.opt.FileSystem = &LocalFileSystem{}
}
if len(r.opt.Extensions) == 0 {
r.opt.Extensions = []string{".tmpl"}
}
if len(r.opt.BinaryContentType) == 0 {
r.opt.BinaryContentType = ContentBinary
}
if len(r.opt.HTMLContentType) == 0 {
r.opt.HTMLContentType = ContentHTML
}
if len(r.opt.JSONContentType) == 0 {
r.opt.JSONContentType = ContentJSON
}
if len(r.opt.JSONPContentType) == 0 {
r.opt.JSONPContentType = ContentJSONP
}
if len(r.opt.TextContentType) == 0 {
r.opt.TextContentType = ContentText
}
if len(r.opt.XMLContentType) == 0 {
r.opt.XMLContentType = ContentXML
}
if r.opt.BufferPool == nil {
r.opt.BufferPool = NewSizedBufferPool(32, 1<<19) // 32 buffers of size 512KiB each
}
if r.opt.IsDevelopment || r.opt.UseMutexLock {
r.lock = &sync.RWMutex{}
} else {
r.lock = &emptyLock{}
}
}
func (r *Render) CompileTemplates() {
if r.opt.Asset == nil || r.opt.AssetNames == nil {
r.compileTemplatesFromDir()
return
}
r.compileTemplatesFromAsset()
}
func (r *Render) compileTemplatesFromDir() {
dir := r.opt.Directory
tmpTemplates := template.New(dir)
tmpTemplates.Delims(r.opt.Delims.Left, r.opt.Delims.Right)
var watcher *fsnotify.Watcher
if r.opt.IsDevelopment {
var err error
watcher, err = fsnotify.NewWatcher()
if err != nil {
log.Printf("Unable to create new watcher for template files. Templates will be recompiled on every render. Error: %v\n", err)
}
}
// Walk the supplied directory and compile any files that match our extension list.
_ = r.opt.FileSystem.Walk(dir, func(path string, info os.FileInfo, _ error) error {
// Fix same-extension-dirs bug: some dir might be named to: "users.tmpl", "local.html".
// These dirs should be excluded as they are not valid golang templates, but files under
// them should be treat as normal.
// If is a dir, return immediately (dir is not a valid golang template).
if info != nil && watcher != nil {
_ = watcher.Add(path)
}
if info == nil || info.IsDir() {
return nil
}
rel, err := filepath.Rel(dir, path)
if err != nil {
return err
}
ext := ""
if strings.Contains(rel, ".") {
ext = filepath.Ext(rel)
}
for _, extension := range r.opt.Extensions {
if ext == extension {
buf, err := r.opt.FileSystem.ReadFile(path)
if err != nil {
panic(err)
}
name := (rel[0 : len(rel)-len(ext)])
tmpl := tmpTemplates.New(filepath.ToSlash(name))
// Add our funcmaps.
for _, funcs := range r.opt.Funcs {
tmpl.Funcs(funcs)
}
// Break out if this parsing fails. We don't want any silent server starts.
template.Must(tmpl.Funcs(helperFuncs).Parse(string(buf)))
break
}
}
return nil
})
r.lock.Lock()
defer r.lock.Unlock()
r.templates = tmpTemplates
if r.hasWatcher = watcher != nil; r.hasWatcher {
go func() {
select {
case _, ok := <-watcher.Events:
if !ok {
return
}
case _, ok := <-watcher.Errors:
if !ok {
return
}
}
watcher.Close()
r.CompileTemplates()
}()
}
}
func (r *Render) compileTemplatesFromAsset() {
dir := r.opt.Directory
tmpTemplates := template.New(dir)
tmpTemplates.Delims(r.opt.Delims.Left, r.opt.Delims.Right)
for _, path := range r.opt.AssetNames() {
if !strings.HasPrefix(path, dir) {
continue
}
rel, err := filepath.Rel(dir, path)
if err != nil {
panic(err)
}
ext := ""
if strings.Contains(rel, ".") {
ext = "." + strings.Join(strings.Split(rel, ".")[1:], ".")
}
for _, extension := range r.opt.Extensions {
if ext == extension {
buf, err := r.opt.Asset(path)
if err != nil {
panic(err)
}
name := (rel[0 : len(rel)-len(ext)])
tmpl := tmpTemplates.New(filepath.ToSlash(name))
// Add our funcmaps.
for _, funcs := range r.opt.Funcs {
tmpl.Funcs(funcs)
}
// Break out if this parsing fails. We don't want any silent server starts.
template.Must(tmpl.Funcs(helperFuncs).Parse(string(buf)))
break
}
}
}
r.lock.Lock()
defer r.lock.Unlock()
r.templates = tmpTemplates
}
// TemplateLookup is a wrapper around template.Lookup and returns
// the template with the given name that is associated with t, or nil
// if there is no such template.
func (r *Render) TemplateLookup(t string) *template.Template {
r.lock.RLock()
defer r.lock.RUnlock()
return r.templates.Lookup(t)
}
func (r *Render) execute(templates *template.Template, name string, binding interface{}) (*bytes.Buffer, error) {
buf := new(bytes.Buffer)
return buf, templates.ExecuteTemplate(buf, name, binding)
}
func (r *Render) layoutFuncs(templates *template.Template, name string, binding interface{}) template.FuncMap {
return template.FuncMap{
"yield": func() (template.HTML, error) {
buf, err := r.execute(templates, name, binding)
// Return safe HTML here since we are rendering our own template.
return template.HTML(buf.String()), err
},
"current": func() (string, error) {
return name, nil
},
"block": func(partialName string) (template.HTML, error) {
log.Println("Render's `block` implementation is now depericated. Use `partial` as a drop in replacement.")
fullPartialName := fmt.Sprintf("%s-%s", partialName, name)
if templates.Lookup(fullPartialName) == nil && r.opt.RenderPartialsWithoutPrefix {
fullPartialName = partialName
}
if r.opt.RequireBlocks || templates.Lookup(fullPartialName) != nil {
buf, err := r.execute(templates, fullPartialName, binding)
// Return safe HTML here since we are rendering our own template.
return template.HTML(buf.String()), err
}
return "", nil
},
"partial": func(partialName string) (template.HTML, error) {
fullPartialName := fmt.Sprintf("%s-%s", partialName, name)
if templates.Lookup(fullPartialName) == nil && r.opt.RenderPartialsWithoutPrefix {
fullPartialName = partialName
}
if r.opt.RequirePartials || templates.Lookup(fullPartialName) != nil {
buf, err := r.execute(templates, fullPartialName, binding)
// Return safe HTML here since we are rendering our own template.
return template.HTML(buf.String()), err
}
return "", nil
},
}
}
func (r *Render) prepareHTMLOptions(htmlOpt []HTMLOptions) HTMLOptions {
layout := r.opt.Layout
funcs := template.FuncMap{}
for _, tmp := range r.opt.Funcs {
for k, v := range tmp {
funcs[k] = v
}
}
if len(htmlOpt) > 0 {
opt := htmlOpt[0]
if len(opt.Layout) > 0 {
layout = opt.Layout
}
for k, v := range opt.Funcs {
funcs[k] = v
}
}
return HTMLOptions{
Layout: layout,
Funcs: funcs,
}
}
// Render is the generic function called by XML, JSON, Data, HTML, and can be called by custom implementations.
func (r *Render) Render(w io.Writer, e Engine, data interface{}) error {
err := e.Render(w, data)
if hw, ok := w.(http.ResponseWriter); err != nil && !r.opt.DisableHTTPErrorRendering && ok {
http.Error(hw, err.Error(), http.StatusInternalServerError)
}
return err
}
// Data writes out the raw bytes as binary data.
func (r *Render) Data(w io.Writer, status int, v []byte) error {
head := Head{
ContentType: r.opt.BinaryContentType,
Status: status,
}
d := Data{
Head: head,
}
return r.Render(w, d, v)
}
// HTML builds up the response from the specified template and bindings.
func (r *Render) HTML(w io.Writer, status int, name string, binding interface{}, htmlOpt ...HTMLOptions) error {
// If we are in development mode, recompile the templates on every HTML request.
r.lock.RLock() // rlock here because we're reading the hasWatcher
if r.opt.IsDevelopment && !r.hasWatcher {
r.lock.RUnlock() // runlock here because CompileTemplates will lock
r.CompileTemplates()
r.lock.RLock()
}
templates := r.templates
r.lock.RUnlock()
opt := r.prepareHTMLOptions(htmlOpt)
if tpl := templates.Lookup(name); tpl != nil {
if len(opt.Layout) > 0 {
tpl.Funcs(r.layoutFuncs(templates, name, binding))
name = opt.Layout
}
if len(opt.Funcs) > 0 {
tpl.Funcs(opt.Funcs)
}
}
head := Head{
ContentType: r.opt.HTMLContentType + r.compiledCharset,
Status: status,
}
h := HTML{
Head: head,
Name: name,
Templates: templates,
bp: r.opt.BufferPool,
}
return r.Render(w, h, binding)
}
// JSON marshals the given interface object and writes the JSON response.
func (r *Render) JSON(w io.Writer, status int, v interface{}) error {
head := Head{
ContentType: r.opt.JSONContentType + r.compiledCharset,
Status: status,
}
j := JSON{
Head: head,
Indent: r.opt.IndentJSON,
Prefix: r.opt.PrefixJSON,
UnEscapeHTML: r.opt.UnEscapeHTML,
StreamingJSON: r.opt.StreamingJSON,
}
return r.Render(w, j, v)
}
// JSONP marshals the given interface object and writes the JSON response.
func (r *Render) JSONP(w io.Writer, status int, callback string, v interface{}) error {
head := Head{
ContentType: r.opt.JSONPContentType + r.compiledCharset,
Status: status,
}
j := JSONP{
Head: head,
Indent: r.opt.IndentJSON,
Callback: callback,
}
return r.Render(w, j, v)
}
// Text writes out a string as plain text.
func (r *Render) Text(w io.Writer, status int, v string) error {
head := Head{
ContentType: r.opt.TextContentType + r.compiledCharset,
Status: status,
}
t := Text{
Head: head,
}
return r.Render(w, t, v)
}
// XML marshals the given interface object and writes the XML response.
func (r *Render) XML(w io.Writer, status int, v interface{}) error {
head := Head{
ContentType: r.opt.XMLContentType + r.compiledCharset,
Status: status,
}
x := XML{
Head: head,
Indent: r.opt.IndentXML,
Prefix: r.opt.PrefixXML,
}
return r.Render(w, x, v)
}