hugo/tpl/template.go

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// 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"
"time"
"text/template/parse"
"html/template"
texttemplate "text/template"
bp "github.com/gohugoio/hugo/bufferpool"
"github.com/gohugoio/hugo/metrics"
)
var (
_ TemplateExecutor = (*TemplateAdapter)(nil)
)
// TemplateHandler manages the collection of templates.
type TemplateHandler interface {
TemplateFinder
AddTemplate(name, tpl string) error
AddLateTemplate(name, tpl string) error
Add support for theme composition and inheritance This commit adds support for theme composition and inheritance in Hugo. With this, it helps thinking about a theme as a set of ordered components: ```toml theme = ["my-shortcodes", "base-theme", "hyde"] ``` The theme definition example above in `config.toml` creates a theme with the 3 components with presedence from left to right. So, Hugo will, for any given file, data entry etc., look first in the project, and then in `my-shortcode`, `base-theme` and lastly `hyde`. Hugo uses two different algorithms to merge the filesystems, depending on the file type: * For `i18n` and `data` files, Hugo merges deeply using the translation id and data key inside the files. * For `static`, `layouts` (templates) and `archetypes` files, these are merged on file level. So the left-most file will be chosen. The name used in the `theme` definition above must match a folder in `/your-site/themes`, e.g. `/your-site/themes/my-shortcodes`. There are plans to improve on this and get a URL scheme so this can be resolved automatically. Also note that a component that is part of a theme can have its own configuration file, e.g. `config.toml`. There are currently some restrictions to what a theme component can configure: * `params` (global and per language) * `menu` (global and per language) * `outputformats` and `mediatypes` The same rules apply here: The left-most param/menu etc. with the same ID will win. There are some hidden and experimental namespace support in the above, which we will work to improve in the future, but theme authors are encouraged to create their own namespaces to avoid naming conflicts. A final note: Themes/components can also have a `theme` definition in their `config.toml` and similar, which is the "inheritance" part of this commit's title. This is currently not supported by the Hugo theme site. We will have to wait for some "auto dependency" feature to be implemented for that to happen, but this can be a powerful feature if you want to create your own theme-variant based on others. Fixes #4460 Fixes #4450
2018-03-01 09:01:25 -05:00
LoadTemplates(prefix string)
PrintErrors()
Add Hugo Piper with SCSS support and much more Before this commit, you would have to use page bundles to do image processing etc. in Hugo. This commit adds * A new `/assets` top-level project or theme dir (configurable via `assetDir`) * A new template func, `resources.Get` which can be used to "get a resource" that can be further processed. This means that you can now do this in your templates (or shortcodes): ```bash {{ $sunset := (resources.Get "images/sunset.jpg").Fill "300x200" }} ``` This also adds a new `extended` build tag that enables powerful SCSS/SASS support with source maps. To compile this from source, you will also need a C compiler installed: ``` HUGO_BUILD_TAGS=extended mage install ``` Note that you can use output of the SCSS processing later in a non-SCSSS-enabled Hugo. The `SCSS` processor is a _Resource transformation step_ and it can be chained with the many others in a pipeline: ```bash {{ $css := resources.Get "styles.scss" | resources.ToCSS | resources.PostCSS | resources.Minify | resources.Fingerprint }} <link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen"> ``` The transformation funcs above have aliases, so it can be shortened to: ```bash {{ $css := resources.Get "styles.scss" | toCSS | postCSS | minify | fingerprint }} <link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen"> ``` A quick tip would be to avoid the fingerprinting part, and possibly also the not-superfast `postCSS` when you're doing development, as it allows Hugo to be smarter about the rebuilding. Documentation will follow, but have a look at the demo repo in https://github.com/bep/hugo-sass-test New functions to create `Resource` objects: * `resources.Get` (see above) * `resources.FromString`: Create a Resource from a string. New `Resource` transformation funcs: * `resources.ToCSS`: Compile `SCSS` or `SASS` into `CSS`. * `resources.PostCSS`: Process your CSS with PostCSS. Config file support (project or theme or passed as an option). * `resources.Minify`: Currently supports `css`, `js`, `json`, `html`, `svg`, `xml`. * `resources.Fingerprint`: Creates a fingerprinted version of the given Resource with Subresource Integrity.. * `resources.Concat`: Concatenates a list of Resource objects. Think of this as a poor man's bundler. * `resources.ExecuteAsTemplate`: Parses and executes the given Resource and data context (e.g. .Site) as a Go template. Fixes #4381 Fixes #4903 Fixes #4858
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NewTextTemplate() TemplateParseFinder
MarkReady()
RebuildClone()
}
// TemplateFinder finds templates.
type TemplateFinder interface {
Add Hugo Piper with SCSS support and much more Before this commit, you would have to use page bundles to do image processing etc. in Hugo. This commit adds * A new `/assets` top-level project or theme dir (configurable via `assetDir`) * A new template func, `resources.Get` which can be used to "get a resource" that can be further processed. This means that you can now do this in your templates (or shortcodes): ```bash {{ $sunset := (resources.Get "images/sunset.jpg").Fill "300x200" }} ``` This also adds a new `extended` build tag that enables powerful SCSS/SASS support with source maps. To compile this from source, you will also need a C compiler installed: ``` HUGO_BUILD_TAGS=extended mage install ``` Note that you can use output of the SCSS processing later in a non-SCSSS-enabled Hugo. The `SCSS` processor is a _Resource transformation step_ and it can be chained with the many others in a pipeline: ```bash {{ $css := resources.Get "styles.scss" | resources.ToCSS | resources.PostCSS | resources.Minify | resources.Fingerprint }} <link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen"> ``` The transformation funcs above have aliases, so it can be shortened to: ```bash {{ $css := resources.Get "styles.scss" | toCSS | postCSS | minify | fingerprint }} <link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen"> ``` A quick tip would be to avoid the fingerprinting part, and possibly also the not-superfast `postCSS` when you're doing development, as it allows Hugo to be smarter about the rebuilding. Documentation will follow, but have a look at the demo repo in https://github.com/bep/hugo-sass-test New functions to create `Resource` objects: * `resources.Get` (see above) * `resources.FromString`: Create a Resource from a string. New `Resource` transformation funcs: * `resources.ToCSS`: Compile `SCSS` or `SASS` into `CSS`. * `resources.PostCSS`: Process your CSS with PostCSS. Config file support (project or theme or passed as an option). * `resources.Minify`: Currently supports `css`, `js`, `json`, `html`, `svg`, `xml`. * `resources.Fingerprint`: Creates a fingerprinted version of the given Resource with Subresource Integrity.. * `resources.Concat`: Concatenates a list of Resource objects. Think of this as a poor man's bundler. * `resources.ExecuteAsTemplate`: Parses and executes the given Resource and data context (e.g. .Site) as a Go template. Fixes #4381 Fixes #4903 Fixes #4858
2018-02-20 04:02:14 -05:00
Lookup(name string) (Template, bool)
}
// Template is the common interface between text/template and html/template.
type Template interface {
Execute(wr io.Writer, data interface{}) error
Name() string
}
Add Hugo Piper with SCSS support and much more Before this commit, you would have to use page bundles to do image processing etc. in Hugo. This commit adds * A new `/assets` top-level project or theme dir (configurable via `assetDir`) * A new template func, `resources.Get` which can be used to "get a resource" that can be further processed. This means that you can now do this in your templates (or shortcodes): ```bash {{ $sunset := (resources.Get "images/sunset.jpg").Fill "300x200" }} ``` This also adds a new `extended` build tag that enables powerful SCSS/SASS support with source maps. To compile this from source, you will also need a C compiler installed: ``` HUGO_BUILD_TAGS=extended mage install ``` Note that you can use output of the SCSS processing later in a non-SCSSS-enabled Hugo. The `SCSS` processor is a _Resource transformation step_ and it can be chained with the many others in a pipeline: ```bash {{ $css := resources.Get "styles.scss" | resources.ToCSS | resources.PostCSS | resources.Minify | resources.Fingerprint }} <link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen"> ``` The transformation funcs above have aliases, so it can be shortened to: ```bash {{ $css := resources.Get "styles.scss" | toCSS | postCSS | minify | fingerprint }} <link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen"> ``` A quick tip would be to avoid the fingerprinting part, and possibly also the not-superfast `postCSS` when you're doing development, as it allows Hugo to be smarter about the rebuilding. Documentation will follow, but have a look at the demo repo in https://github.com/bep/hugo-sass-test New functions to create `Resource` objects: * `resources.Get` (see above) * `resources.FromString`: Create a Resource from a string. New `Resource` transformation funcs: * `resources.ToCSS`: Compile `SCSS` or `SASS` into `CSS`. * `resources.PostCSS`: Process your CSS with PostCSS. Config file support (project or theme or passed as an option). * `resources.Minify`: Currently supports `css`, `js`, `json`, `html`, `svg`, `xml`. * `resources.Fingerprint`: Creates a fingerprinted version of the given Resource with Subresource Integrity.. * `resources.Concat`: Concatenates a list of Resource objects. Think of this as a poor man's bundler. * `resources.ExecuteAsTemplate`: Parses and executes the given Resource and data context (e.g. .Site) as a Go template. Fixes #4381 Fixes #4903 Fixes #4858
2018-02-20 04:02:14 -05:00
// 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
}
// TemplateExecutor adds some extras to Template.
type TemplateExecutor interface {
Template
ExecuteToString(data interface{}) (string, error)
Tree() string
}
// TemplateDebugger prints some debug info to stdoud.
type TemplateDebugger interface {
Debug()
}
// TemplateAdapter implements the TemplateExecutor interface.
type TemplateAdapter struct {
Template
Metrics metrics.Provider
}
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// Execute executes the current template. The actual execution is performed
// by the embedded text or html template, but we add an implementation here so
// we can add a timer for some metrics.
func (t *TemplateAdapter) Execute(w io.Writer, data interface{}) error {
if t.Metrics != nil {
defer t.Metrics.MeasureSince(t.Name(), time.Now())
}
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return t.Template.Execute(w, data)
}
// 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 == nil || tree.Root == nil {
return ""
}
s := tree.Root.String()
return s
}
// TemplateFuncsGetter allows to get a map of functions.
type TemplateFuncsGetter interface {
GetFuncs() map[string]interface{}
}
// 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{})
}