hugo/tpl/template.go
Bjørn Erik Pedersen 8b5b558bb5 tpl: Rework to handle both text and HTML templates
Before this commit, Hugo used `html/template` for all Go templates.

While this is a fine choice for HTML and maybe also RSS feeds, it is painful for plain text formats such as CSV, JSON etc.

This commit fixes that by using the `IsPlainText` attribute on the output format to decide what to use.

A couple of notes:

* The above requires a nonambiguous template name to type mapping. I.e. `/layouts/_default/list.json` will only work if there is only one JSON output format, `/layouts/_default/list.mytype.json` will always work.
* Ambiguous types will fall back to HTML.
* Partials inherits the text vs HTML identificator of the container template. This also means that plain text templates can only include plain text partials.
* Shortcode templates are, by definition, currently HTML templates only.

Fixes #3221
2017-04-02 23:13:10 +02:00

103 lines
2.6 KiB
Go

// Copyright 2017-present The Hugo Authors. All rights reserved.
//
// 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 tpl
import (
"io"
"text/template/parse"
"html/template"
texttemplate "text/template"
bp "github.com/spf13/hugo/bufferpool"
)
var (
_ TemplateExecutor = (*TemplateAdapter)(nil)
)
// TemplateHandler manages the collection of templates.
type TemplateHandler interface {
TemplateFinder
AddTemplate(name, tpl string) error
AddLateTemplate(name, tpl string) error
LoadTemplates(absPath, prefix string)
PrintErrors()
MarkReady()
RebuildClone()
}
// TemplateFinder finds templates.
type TemplateFinder interface {
Lookup(name string) *TemplateAdapter
}
// Template is the common interface between text/template and html/template.
type Template interface {
Execute(wr io.Writer, data interface{}) error
Name() string
}
// TemplateExecutor adds some extras to Template.
type TemplateExecutor interface {
Template
ExecuteToString(data interface{}) (string, error)
Tree() string
}
// TemplateAdapter implements the TemplateExecutor interface.
type TemplateAdapter struct {
Template
}
// ExecuteToString executes the current template and returns the result as a
// string.
func (t *TemplateAdapter) ExecuteToString(data interface{}) (string, error) {
b := bp.GetBuffer()
defer bp.PutBuffer(b)
if err := t.Execute(b, data); err != nil {
return "", err
}
return b.String(), nil
}
// Tree returns the template Parse tree as a string.
// Note: this isn't safe for parallel execution on the same template
// vs Lookup and Execute.
func (t *TemplateAdapter) Tree() string {
var tree *parse.Tree
switch tt := t.Template.(type) {
case *template.Template:
tree = tt.Tree
case *texttemplate.Template:
tree = tt.Tree
default:
panic("Unknown template")
}
if tree.Root == nil {
return ""
}
s := tree.Root.String()
return s
}
// TemplateTestMocker adds a way to override some template funcs during tests.
// The interface is named so it's not used in regular application code.
type TemplateTestMocker interface {
SetFuncs(funcMap map[string]interface{})
}