gorazor
gorazor is the Go port of the razor view engine originated from asp.net in 2011. In summary, gorazor is:
- Extremely Fast. Templates are converted into Go code and then compiled with optimizations.
- Concise syntax, no delimiter like
<?,<%, or{{.- Original Razor Syntax & quick reference for asp.net.
- Able to mix go code in view template
- Insert code block to import & call arbitrary go modules & functions
- Flow controls are just Go, no need to learn another mini-language
- Code generation approach
- No reflection overhead
- Go compiler validation for free
- Strong type view model
- Embedding templates support
- Layout/Section support
Extremely Fast
gorazor is about 20X times faster than html/template when using standard strings.Builder for template writing.
When using quicktemplate's ByteBuffer and unsafeStrToBytes method to for template writing, gorazor's performance is comparable to quicktemplate, if not faster.
Benchmark results:
$ go test -bench='Benchmark(Razor|RazorQuick|Quick|HTML)Template' -benchmem github.com/valyala/quicktemplate/tests github.com/sipin/gorazor/tests
goos: windows
goarch: amd64
pkg: github.com/valyala/quicktemplate/tests
BenchmarkQuickTemplate1-8 50000000 35.6 ns/op 0 B/op 0 allocs/op
BenchmarkQuickTemplate10-8 10000000 152 ns/op 0 B/op 0 allocs/op
BenchmarkQuickTemplate100-8 1000000 1460 ns/op 0 B/op 0 allocs/op
BenchmarkHTMLTemplate1-8 2000000 712 ns/op 608 B/op 21 allocs/op
BenchmarkHTMLTemplate10-8 500000 3586 ns/op 2834 B/op 111 allocs/op
BenchmarkHTMLTemplate100-8 50000 35180 ns/op 28055 B/op 1146 allocs/op
PASS
ok github.com/valyala/quicktemplate/tests 11.360s
goos: windows
goarch: amd64
pkg: github.com/sipin/gorazor/tests
BenchmarkRazorTemplate1-8 30000000 49.8 ns/op 224 B/op 3 allocs/op
BenchmarkRazorTemplate10-8 10000000 122 ns/op 480 B/op 4 allocs/op
BenchmarkRazorTemplate100-8 2000000 931 ns/op 4064 B/op 7 allocs/op
BenchmarkRazorQuickTemplate1-8 100000000 19.9 ns/op 0 B/op 0 allocs/op
BenchmarkRazorQuickTemplate10-8 20000000 82.5 ns/op 0 B/op 0 allocs/op
BenchmarkRazorQuickTemplate100-8 2000000 767 ns/op 0 B/op 0 allocs/op
BenchmarkRazorQuickTemplateOriginal1-8 100000000 17.4 ns/op 0 B/op 0 allocs/op
BenchmarkRazorQuickTemplateOriginal10-8 20000000 68.8 ns/op 0 B/op 0 allocs/op
BenchmarkRazorQuickTemplateOriginal100-8 2000000 656 ns/op 0 B/op 0 allocs/op
PASS
ok github.com/sipin/gorazor/tests 19.921s
BenchmarkRazorQuickTemplate's manually modified ensure exact output as quicktemplate for comparism.BenchmarkRazorQuickTemplateOriginalaregorazor's default code-gen, which produce less white-space, thus faster.
Usage
gorazor supports go 1.10 and above, for go version below 1.10, you may use gorazor classic version.
go 1.12 are recommended for better compiler optimization.
Install
go get github.com/sipin/gorazor
Usage
- Process folder:
gorazor template_folder output_folder - Process file:
gorazor template_file output_file
Examples
[Examples] gives examples using layout / helper etc.
When using layout, you may need to set -prefix parameter, like:
git clone https://github.com/sipin/gorazor/
cd gorazor
go build
# -prefix parameter here tells gorazor the current folder is the base path for github.com/sipin/gorazor
# So that, when importing "github.com/sipin/gorazor/examples/tpl/layout" in example/tpl/home.gohtml
# gorazor will know how to find the layout/helper files
./gorazor -prefix github.com/sipin/gorazor ./examples/tpl ./examples/tpl
go run example/main.go
Syntax
Variable
@variableto insert string variable into html template- variable could be wrapped by arbitrary go functions
- variable inserted will be automatically escaped
<div>Hello @user.Name</div>
<div>Hello @strings.ToUpper(req.CurrentUser.Name)</div>
Use raw to skip escaping:
<div>@raw(user.Name)</div>
Only use raw when you are 100% sure what you are doing, please always be aware of XSS attack.
Flow Control
@if .... {
....
}
@if .... {
....
} else {
....
}
@for .... {
}
@{
switch .... {
case ....:
<p>...</p>
case 2:
<p>...</p>
default:
<p>...</p>
}
}
Please use example for reference.
Code block
Arbitrary go code could be used in templates, like creating a new variable.
@{
username := u.Name
if u.Email != "" {
username += "(" + u.Email + ")"
}
}
<div class="welcome">
<h4>Hello @username</h4>
</div>
It's recommended to keep clean separation of code & view. Please consider move logic into your code before creating a code block in a template.
Declaration
The first code block in template is strictly for declaration:
- imports
- model type
- layout
like:
@{
import (
"kp/models" //import `"kp/models"` package
"tpl/layout" //import tpl/layout namespace
)
layout := layout.Base //Use layout package's **Base func** for layout
var user *models.User //1st template param
var blog *models.Blog //2nd template param
}
...
first code block must be at the beginning of the template, i.e. before any html.
Any other codes inside the first code block will be ignored.
import must be wrapped in (), import "package_name" is not yet supported.
The variables declared in first code block will be the models of the template, i.e. the parameters of generated function.
If your template doesn't need any model input, then just leave it blank.
Helper / Include other template
As gorazor compiles templates to go function, embedding another template is just calling the generated function, like any other go function.
However, if the templates are designed to be embedded, they must be under helper namespace, i.e. put them in helper sub-folder.
So, using a helper template is similar to:
@if msg != "" {
<div>@helper.ShowMsg(msg)</div>
}
gorazor won't HTML escape the output of helper.XXX.
Please use example for reference.
Layout & Section
The syntax for declaring layout is a bit tricky, in the example mentioned above:
@{
import (
"tpl/layout"
)
layout := layout.Base //Use layout package's **base func** for layout
}
"tpl/layout" is the layout package namespace, and the layout variable refers to "layout.Base" func, which should be generated by tpl/layout/base.gohtml.
Must use
layoutas the variable name
Package / Variable convention
- The namespace/folder name for layout templates must be
layoutgorazorrelies on this to determine if a template is for layout
- The template
variable namealso must belayout
A layout file tpl/layout/base.gohtml may look like:
@{
var body string
var sidebar string
var footer string
var title string
var css string
var js string
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>@title</title>
</head>
<body>
<div class="container">@body</div>
<div class="sidebar">@sidebar</div>
<div class="footer">@footer</div>
@js
</body>
</html>
It's just a usual gorazor template, but:
- First param must be
var body string(As it's always required, maybe we could remove it in future?) - All params must be string, each param is considered as a section, the variable name is the section name.
- Under
layoutpackage, i.e. within "layout" folder.- Optionally, use
isLayout := trueto declare a template as layout
- Optionally, use
A template using such layout tpl/index.gohtml may look like:
@{
import (
"tpl/layout"
)
layout := layout.Base
}
@section footer {
<div>Copyright 2014</div>
}
<h2>Welcome to homepage</h2>
It's also possible to use import alias:
@{
import (
share "tpl/layout"
)
layout := share.Base
}
With the page, the page content will be treated as the body section in the layout.
The other section content need to be wrapped with
@section SectionName {
....
}
The template doesn't need to specify all sections defined in the layout. If a section is not specified, it will be considered as "".
Thus, it's possible for the layout to define default section content in such manner:
@{
var body string
var sidebar string
}
<body>
<div class="container">@body</div>
@if sidebar == "" {
<div class="sidebar">I'm the default side bar</div>
} else {
<div class="sidebar">@sidebar</div>
}
</body>
- A layout should be able to use another layout, it's just function call.
Conventions
- Template folder name will be used as package name in generated code
- Template file name must has the extension name
.gohtml - Template strip of
.gohtmlextension name will be used as the function name in generated code, with first letter Capitalized.- So that the function will be accessible to other modules. (I hate GO about this.)
- Helper templates must has the package name helper, i.e. in
helperfolder. - Layout templates must has the package name layout, i.e. in
layoutfolder.
Example
Here is a simple example of gorazor templates and the corresponding generated codes.
FAQ
IDE / Editor support?
Sublime Text 2/3
- Syntax highlight Search & install
gorazorvia Package Control. - Context aware auto-completion, you may need to manually modify GoSublime package, bascially replace
gscomplete.pyin with this andgslint.pywith this
Emacs
web-mode supports Razor template engine, so add this into your Emacs config file:
(require 'web-mode)
(add-hook 'web-mode-hook 'my-web-mode-hook)
(add-to-list 'auto-mode-alist '("\\.html?\\'" . web-mode))
(add-to-list 'auto-mode-alist '("\\.gohtml\\'" . web-mode))
(add-to-list 'auto-mode-alist '("\\.js\\'" . web-mode))
(setq web-mode-engines-alist '(("razor" . "\\.gohtml\\'")))
Credits
The very first version of gorazor is a hack of razor's port in javascript: vash, thus requires node's to run.
gorazor has been though several rounds of refactoring, and it has completely rewritten in pure Go. Nonetheless, THANK YOU @kirbysayshi for Vash! Without Vash, gorazor may never start.
LICENSE
LICENSE? Well, WTFPL and 996.icu.
