hugo/tpl/template.go
2020-07-03 23:31:51 +02:00

142 lines
3.7 KiB
Go

// Copyright 2019 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 (
"reflect"
"io"
"regexp"
"github.com/gohugoio/hugo/output"
texttemplate "github.com/gohugoio/hugo/tpl/internal/go_templates/texttemplate"
)
// TemplateManager manages the collection of templates.
type TemplateManager interface {
TemplateHandler
TemplateFuncGetter
AddTemplate(name, tpl string) error
MarkReady() error
}
// TemplateVariants describes the possible variants of a template.
// All of these may be empty.
type TemplateVariants struct {
Language string
OutputFormat output.Format
}
// TemplateFinder finds templates.
type TemplateFinder interface {
TemplateLookup
TemplateLookupVariant
}
// TemplateHandler finds and executes templates.
type TemplateHandler interface {
TemplateFinder
Execute(t Template, wr io.Writer, data interface{}) error
LookupLayout(d output.LayoutDescriptor, f output.Format) (Template, bool, error)
HasTemplate(name string) bool
}
type TemplateLookup interface {
Lookup(name string) (Template, bool)
}
type TemplateLookupVariant interface {
// TODO(bep) this currently only works for shortcodes.
// We may unify and expand this variant pattern to the
// other templates, but we need this now for the shortcodes to
// quickly determine if a shortcode has a template for a given
// output format.
// It returns the template, if it was found or not and if there are
// alternative representations (output format, language).
// We are currently only interested in output formats, so we should improve
// this for speed.
LookupVariant(name string, variants TemplateVariants) (Template, bool, bool)
LookupVariants(name string) []Template
}
// Template is the common interface between text/template and html/template.
type Template interface {
Name() string
Prepare() (*texttemplate.Template, error)
}
// TemplateParser is used to parse ad-hoc templates, e.g. in the Resource chain.
type TemplateParser interface {
Parse(name, tpl string) (Template, error)
}
// TemplateParseFinder provides both parsing and finding.
type TemplateParseFinder interface {
TemplateParser
TemplateFinder
}
// TemplateDebugger prints some debug info to stdoud.
type TemplateDebugger interface {
Debug()
}
// templateInfo wraps a Template with some additional information.
type templateInfo struct {
Template
Info
}
// templateInfo wraps a Template with some additional information.
type templateInfoManager struct {
Template
InfoManager
}
// TemplatesProvider as implemented by deps.Deps.
type TemplatesProvider interface {
Tmpl() TemplateHandler
TextTmpl() TemplateParseFinder
}
// WithInfo wraps the info in a template.
func WithInfo(templ Template, info Info) Template {
if manager, ok := info.(InfoManager); ok {
return &templateInfoManager{
Template: templ,
InfoManager: manager,
}
}
return &templateInfo{
Template: templ,
Info: info,
}
}
var baseOfRe = regexp.MustCompile("template: (.*?):")
func extractBaseOf(err string) string {
m := baseOfRe.FindStringSubmatch(err)
if len(m) == 2 {
return m[1]
}
return ""
}
// TemplateFuncGetter allows to find a template func by name.
type TemplateFuncGetter interface {
GetFunc(name string) (reflect.Value, bool)
}