Documentation - Traditional web application - Template functions

The internal/funcs/funcs.go file contains a selection of helper functions for use in templates.

These functions are automatically available in your HTML templates when rendering with response.Page() or response.NamedTemplate(). If you selected the emails feature when generating your codebase, they are also available in email templates when using app.mailer.Send().

The following functions are included:

Function	Description	Example
`now`	Returns the current time as `time.Time`.	`{{ now }}`
`timeSince arg1`	Returns the time elapsed since `arg1 time.Time` as a `time.Duration`.	`{{ timeSince .CreatedAt }}`
`timeUntil arg1`	Returns the time until `arg1 time.Time` as a `time.Duration`.	`{{ timeUntil .ExpiresAt }}`
`formatTime arg1 arg2`	Returns `arg2 time.Time` formatted using the pattern `arg1 string`.	`{{ formatTime "2006-01-02" .CreatedAt }}`
`approxDuration arg1`	Returns the approximate duration of `arg1 time.Duration` in a human-friendly format.	`{{ approxDuration (timeSince .CreatedAt) }}`
`uppercase arg1`	Returns `arg1 string` converted to uppercase.	`{{ uppercase .Name }}`
`lowercase arg1`	Returns `arg1 string` converted to lowercase.	`{{ lowercase .Name }}`
`pluralize arg1 arg2 arg3`	If `arg1 any` equals `1`, returns `arg2 string`; otherwise returns `arg3 string`.	`{{ pluralize .Count "item" "items" }}`
`slugify arg1`	Returns `arg1 string` in lowercase with non-ASCII characters and punctuation removed, and whitespace replaced with hyphens.	`{{ slugify .Title }}`
`safeHTML arg1`	Outputs `arg1 string` as `template.HTML` without escaping. Use only with trusted input.	`{{ safeHTML .Content }}`
`join arg1 arg2`	Returns the values in slice `arg1 []string` joined using the separator `arg2 string`.	`{{ join .Tags ", " }}`
`incr arg1`	Increments `arg1 any` by 1 and returns an `int64`.	`{{ incr .Index }}`
`decr arg1`	Decrements `arg1 any` by 1 and returns an `int64`.	`{{ decr .Index }}`
`formatInt arg1`	Returns `arg1 any` formatted with commas as the thousands separator.	`{{ formatInt .Count }}`
`formatFloat arg1 arg2`	Returns `arg1 float64` rounded to `arg2 int` decimal places and formatted with commas.	`{{ formatFloat .Price 2 }}`
`yesNo arg1`	Returns "Yes" if `arg1 bool` is true, or "No" if false.	`{{ yesNo .Active }}`
`urlSetParam arg1 arg2 arg3`	Returns `arg1 *url.URL` with the key `arg2 string` and value `arg3 any` added to the query string.	`{{ urlSetParam .URL "page" 2 }}`
`urlDelParam arg1 arg2`	Returns `arg1 *url.URL` with the key `arg2 string` removed from the query string.	`{{ urlDelParam .URL "page" }}`

Adding additional template functions

Feel free to edit the internal/funcs/funcs.go file to include any additional functions you need in your templates.

To add a function, define it in internal/funcs/funcs.go and register it in the TemplateFuncs map. For example:

var TemplateFuncs = template.FuncMap{
    ...
    "yourFunction": yourFunction,
}

func yourFunction(s string) (string, error) {
    // Do something...
}

Note that template functions must return either a single value, or two values where the second has type error. See the documentation for template.FuncMap for more details.