View Template Functions
By default Go lang provides set of template functions and aah framework provides template functions to access configuration, request parameters, security check, session values, flash values, etc.
Table of Contents
aah Template Funcs
- config
- import or include
- rurl
- rurlm
- i18n
- pparam
- fparam
- qparam
- flash
- session
- isauthenticated
- hasrole
- hasanyrole
- hasallroles
- ispermitted
- ispermittedall
- safeHTML
Func: config
Accessing application configuration from aah.AppConfig()
.
{{ config "format.datetime" }}
Func: import
Renders the common file from views/common
with ViewArgs and imports into caller template file.
{{ import "sidebar.html" . }}
OR
{{ include "sidebar.html" . }}
Func: rurl
Creates the Reverse URL for the given route name with arguments. Additional arguments are discarded.
- How to access sub-domain URL for reverse route on root domain template file?
- Ans: Use sub-domain (the one use have used in
routes.conf
) prefix before the route name
- Ans: Use sub-domain (the one use have used in
- How to access root-domain URL for reverse route on sub-domain template file?
- Ans: Use
root.
as prefix before the route name
- Ans: Use
- How to I get host url for root domain or sub-domain on template file?
- Ans:
host
is the keyword or virtual route name- For example: this is applicable to
rurlm
func too.{{ rurl "host" }}
- on root domain template file{{ rurl "root.host" }}
- on sub-domain template file{{ rurl "docs.host" }}
- on root domain template file access sub-domain host URL
- For example: this is applicable to
- Ans:
// route name and arguments
// Path: /users/:userId/addresses/:addressId
{{ rurl . "user_address_info" .UserId .Addresses.AddressId }}
// route name
// Path: /login.html
{{ rurl . "login" }}
// ==================================
// How to access sub-domain url by route name?
// Ans: use
{{ rurl . "docs.index"}}
Func: rurlm
Creates the Reverse URL for given route name with map
arguments. Additional arguments added as URL query parameters.
// route name and arguments
// Path: /v1/users/:userId/addresses/:addressId
{{ rurlm . "user_address_info" .MapArguments }}
// route name
// Path: /login.html
{{ rurlm . "login" }}
Func: i18n
Access internationalization and localization message from view templates.
{{ i18n . "label.pages.title.get_involved" }}
Func: pparam
Access Path parameter values.
{{ pparam . "userId" }}
Func: fparam
Access Form parameter values.
{{ fparam . "email" }}
Func: qparam
Access URL Query parameter values.
{{ qparam . "lang" }}
Func: flash
Access Flash values. Note: Flash value is deleted after accessing once.
{{ flash . "Username" }}
Func: session
Access Session object values.
{{ session . "Username" }}
Func: isauthenticated
Returns the value of ctx.Subject().IsAuthenticated
from current request subject.
<!-- show logout option if user is authenticated -->
{{ if isauthenticated . }}
<a href="/logout">Logout</a>
{{ end }}
Func: hasrole
Returns true
, if Subject (aka User) has given role otherwise false
.
{{ if hasrole . "manager" }}
<!-- You have a role "manager" -->
{{ end }}
Func: hasanyrole
Returns true
, if Subject (aka User) has any of the given roles otherwise false
.
{{ if hasanyrole . "manager" "dayshift" }}
<!-- You have any one of the above role -->
{{ end }}
Func: hasallroles
Returns true
, if Subject (aka User) has all the given roles otherwise false
.
{{ if hasallroles . "role1" "role2" "role3" }}
<!-- You have all the roles, congrats -->
{{ end }}
Func: ispermitted
Returns true
if Subject (aka User) has given permission otherwise false
.
{{ if ispermitted . "newsletter:read,write" }}
<!-- You have permission, you may read or write newsletter -->
{{ end }}
Func: ispermittedall
Returns true
if Subject (aka User) has all the given permissions otherwise false
.
{{ if ispermittedall . "newsletter:read,write" "newsletter:12345" }}
<!-- You have permission, you may read or write newsletter of 12345 -->
{{ end }}
Func: safeHTML
Go template strips the HTML comment while rendering the template file. To preserve HTML comment or any special char use safeHTML
template func. Of-course use it with care.
Note: Use only if you trust the HTML source, since it preserves the HTML content without escaping.
<!-- For example: -->
{{ safeHTML `<!--[if lt IE 9]>
<script src="//oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script>
<script src="//oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
<![endif]-->` }}
Adding your custom Funcs or Third-Party Funcs
You add custom template func using aah.AddTemplateFunc
.
func init() {
aah.AddTemplateFunc(template.FuncMap{
"myfuncname": func() string {
return "mycustom function value"
},
})
}
Third-Party Funcs
Adding https://github.com/leekchan/gtf
func init() {
aah.AddTemplateFunc(gtf.GtfFuncMap)
}
Adding https://github.com/Masterminds/sprig
func init() {
aah.AddTemplateFunc(sprig.FuncMap())
}