The ttgen generates Go code from a template description.
The template syntax looks like Perl Template-Toolkit (http://template-toolkit.org/),
but not the same because Go is compiled language.
It's faster than native Go templates in more than 10 times:
BenchmarkGoCoreTemplate-4 3000 5306959 ns/op 1041697 B/op 31035 allocs/op
BenchmarkQBitTemplate-4 30000 407632 ns/op 36096 B/op 4006 allocs/op
go get -u github.com/go-qbit/template
go install github.com/go-qbit/template/ttgen
-
Write a new wrapper for pages in `template/wrapper.gtt``:
[% WRAPPER page(caption string) %] <!DOCTYPE html> <html> <head> <title>[% caption | html %]</title> </head> <body> [% CONTENT %] </<body> </html> [% END %] -
Write a new template in `template/index.gtt``:
[% TEMPLATE Test(header string, users []User) USE WRAPPER page(header) %] <h1>[% header | html %]</h1> <hr> [% FOR user IN users %] <p> [% PROCESS UserName(user) %]: [% user.Age %] ([% IF user.IsMan %]Man[% ELSE %]Woman[% END %]) </p> [% END %] [% END %] [% TEMPLATE UserName(user User) %] [% user.Name | html +%] [% user.Lastname | html %] [% END %] -
Define a
Usertype intemplate/user.go:package template type User struct { Name string Lastname string Age uint8 IsMan bool }
-
Write a
main.gofile that will process the template://go:generate ttgen template/*.gtt package main import ( "context" "os" "template" ) func main() { template.ProcessTest(context.Background(), os.Stdout, "<Header>", []template.User{ {"Ivan", "Sidorov", 20, true}, {"Petr", "Ivanov", 30, true}, }, ) }
-
Generate Go code:
go generate ./... -
Check new Go files in the folder
template, templates will be converted to:template/wrapper.gtt->template/wrapper.gtt.go:package templates import ( "context" "github.com/go-qbit/template/filter" "io" ) var ( sc9e1fc75ad64f59917915544d65154cf = []byte{0x3c, 0x21, 0x44, 0x4f, 0x43, 0x54, 0x59, 0x50, 0x45, 0x20, 0x68, 0x74, 0x6d, 0x6c, 0x3e, 0xa, 0x3c, 0x68, 0x74, 0x6d, 0x6c, 0x3e, 0xa, 0x20, 0x20, 0x20, 0x20, 0x3c, 0x68, 0x65, 0x61, 0x64, 0x3e, 0xa, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x3c, 0x74, 0x69, 0x74, 0x6c, 0x65, 0x3e} sa25bcc91ec51d6fea14a629de184814c = []byte{0x3c, 0x2f, 0x74, 0x69, 0x74, 0x6c, 0x65, 0x3e, 0xa, 0x20, 0x20, 0x20, 0x20, 0x3c, 0x2f, 0x68, 0x65, 0x61, 0x64, 0x3e, 0xa, 0x20, 0x20, 0x20, 0x20, 0x3c, 0x62, 0x6f, 0x64, 0x79, 0x3e} s33e48fc8e2ea8a4250506db7e0be31fd = []byte{0x3c, 0x2f, 0x3c, 0x62, 0x6f, 0x64, 0x79, 0x3e, 0xa, 0x3c, 0x2f, 0x68, 0x74, 0x6d, 0x6c, 0x3e} ) func Wrapperpage(ctx context.Context, w io.Writer, tplClbF func(), caption string) { w.Write(sc9e1fc75ad64f59917915544d65154cf) io.WriteString(w, filter.Filterhtml(caption)) w.Write(sa25bcc91ec51d6fea14a629de184814c) tplClbF() w.Write(s33e48fc8e2ea8a4250506db7e0be31fd) }
template/index.gtt->template/index.gtt.go:package template import ( "context" "github.com/go-qbit/template/filter" "github.com/go-qbit/template/utils" "io" ) var ( s4da1a46ec20cf93ee5c846a51e04f0ed = []byte{0x3c, 0x70, 0x3e} s627661c621eab1b7b298abc47d1a250d = []byte{0x4d, 0x61, 0x6e} s5276343758bbfb9e0a374c9dd2fa6ce7 = []byte{0x57, 0x6f, 0x6d, 0x61, 0x6e} s921c704d576fc50eafc928f28d287019 = []byte{0x29, 0xa, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x3c, 0x2f, 0x70, 0x3e} sa5c0aa5a33c99f4179eb48443e8bb33c = []byte{0x3c, 0x68, 0x31, 0x3e} s2b7c41aee73401e8cd970fba4c3bd4bd = []byte{0x3c, 0x2f, 0x68, 0x31, 0x3e, 0xa, 0x20, 0x20, 0x20, 0x20, 0x3c, 0x68, 0x72, 0x3e} s853ae90f0351324bd73ea615e6487517 = []byte{0x3a} s84c40473414caf2ed4a7b1283e48bbf4 = []byte{0x28} s7215ee9c7d9dc229d2921a40e899ec5f = []byte{0x20} ) func ProcessTest(ctx context.Context, w io.Writer, header string, users []User) { Wrapperpage(ctx, w, func() { w.Write(sa5c0aa5a33c99f4179eb48443e8bb33c) io.WriteString(w, Filterhtml(header)) w.Write(s2b7c41aee73401e8cd970fba4c3bd4bd) for _, user := range users { w.Write(s4da1a46ec20cf93ee5c846a51e04f0ed) ProcessUserName(ctx, w, user) w.Write(s853ae90f0351324bd73ea615e6487517) io.WriteString(w, utils.ToString(user.Age)) w.Write(s84c40473414caf2ed4a7b1283e48bbf4) if user.IsMan { w.Write(s627661c621eab1b7b298abc47d1a250d) } else { w.Write(s5276343758bbfb9e0a374c9dd2fa6ce7) } w.Write(s921c704d576fc50eafc928f28d287019) } }, header) } func ProcessUserName(ctx context.Context, w io.Writer, user User) { io.WriteString(w, Filterhtml(user.Name)) w.Write(s7215ee9c7d9dc229d2921a40e899ec5f) io.WriteString(w, Filterhtml(user.Lastname)) }
-
Run the application:
go run main.go
Template directives are embedded between tags [% and %].
[% IF a == b %]
text
[% END %]
Several directives within one block must be splitted by ;.
[%
IF a == b;
FOR v IN array;
v;
END;
END
%]
You can use multiline comments within tags:
[% a := 10 /* comment */ %]
[% /*
Multiline
comment
*/ %]
By default whitespaces around tags is chomped. The code
Before
[% v1 %] [% v2 %]
After
will produce BeforeV1V2After if v1 == "V1" and v2 == "V2".
To save whitespaces use tag [%+ to save left whitespaces and +%] to save right whitespaces.
The code
Before
[%+ v1 +%] [% v2 +%]
After
will produce
Before
V1 V2
After
if v1 == "V1" and v2 == "V2".
The IMPORT directive declares a list of go packages that will be added to result Go file.
Packages must be quoted by " and splitted by ",". It's optional, but tt must be first directive in a template file if you add it.
[%
IMPORT(
"package1",
"package2"
)
%]
The TEMPLATE directive defines a new template:
[% TEMPLATE <name>(<parameters_list>) USE WRAPPER <wrapper_name>(<parameters_list>) %]
Template content
[% END %]
USE WRAPPER is optional, see WRAPPER for more information.
The WRAPPER directive defines a new template wrapper. The place for content must be declared by CONTENT.
You can use wrappers to define common parts of templates, for example web site header and footer.
[% WRAPPER page(title string) %]
<!DOCTYPE html>
<html lang="ru">
<head>
<title>[% title | html %]</title>
</head>
<body>
[% CONTENT %]
</body>
</html>
[% END %]
Also you can use WRAPPER for WRAPPER:
[% WRAPPER page(title string) USE WRAPPER outer() %]
[% CONTENT %]
[% END %]
The PROCESS directive inserts output of other template to current.
[% PROCESS <template_name>(parameters) %]
The IF / ELSE can be used to process or ignore a block based on some run-time condition.
[% IF a < 10 %]
Less
[% ELSE %]
Greater or equal
[% END %]
The FOR directive will iterate through the items in a list/map
[% FOR item IN list %]
[% item | html %]
[% END %]
[% FOR i, item IN list %]
[% i %]: [% item | html %]
[% END %]
[% FOR key IN map %]
[% key | html %]
[% END %]
[% FOR key, value IN map %]
[% key | html %]: [% value | html %]
[% END %]
or while the last expression of the three is true
[% FOR i:=0; i<100; i++ %]
[% i %]
[% END %]
Any expression can be processed through filter before output
[% varName | filterName1 %]
[% (a + b) | filterName2(10) %]
The html filter escaped dangerous character
=:=
>,GT<,LT>=,GE<=,LE==,EQ
+-*/%
&&,AND||,OR
!,NOT++--