tpl: Add errorf template function

Add template function that will build a string from the given format
string and arguments, then log it to ERROR. This has an intended
side-effect of causing the build to fail, when executed.

Resolves #3817
This commit is contained in:
Brendan Roy 2017-09-30 20:00:19 +10:00 committed by Bjørn Erik Pedersen
parent 47fdfd5196
commit 4fc67fe44a
3 changed files with 41 additions and 2 deletions

View file

@ -0,0 +1,26 @@
---
title: errorf
linktitle: errorf
description: Evaluates a format string and logs it to ERROR.
date: 2017-09-30
publishdate: 2017-09-30
lastmod: 2017-09-30
categories: [functions]
menu:
docs:
parent: "functions"
keywords: [strings, log, error]
signature: ["errorf FORMAT INPUT"]
workson: []
hugoversion:
relatedfuncs: [printf]
deprecated: false
aliases: []
---
`errorf` will evaluate a format string, then output the result to the ERROR log.
This will also cause the build to fail.
```
{{ errorf "Something went horribly wrong! %s" err }}
```

View file

@ -15,15 +15,17 @@ package fmt
import ( import (
_fmt "fmt" _fmt "fmt"
"github.com/gohugoio/hugo/helpers"
) )
// New returns a new instance of the fmt-namespaced template functions. // New returns a new instance of the fmt-namespaced template functions.
func New() *Namespace { func New() *Namespace {
return &Namespace{} return &Namespace{helpers.NewDistinctErrorLogger()}
} }
// Namespace provides template functions for the "fmt" namespace. // Namespace provides template functions for the "fmt" namespace.
type Namespace struct { type Namespace struct {
errorLogger *helpers.DistinctLogger
} }
// Print returns string representation of the passed arguments. // Print returns string representation of the passed arguments.
@ -41,3 +43,8 @@ func (ns *Namespace) Printf(format string, a ...interface{}) string {
func (ns *Namespace) Println(a ...interface{}) string { func (ns *Namespace) Println(a ...interface{}) string {
return _fmt.Sprintln(a...) return _fmt.Sprintln(a...)
} }
func (ns *Namespace) Errorf(format string, a ...interface{}) string {
ns.errorLogger.Printf(format, a...)
return _fmt.Sprintf(format, a...)
}

View file

@ -50,8 +50,14 @@ func init() {
}, },
) )
return ns ns.AddMethodMapping(ctx.Errorf,
[]string{"errorf"},
[][2]string{
{`{{ errorf "%s." "failed" }}`, `failed.`},
},
)
return ns
} }
internal.AddTemplateFuncsNamespace(f) internal.AddTemplateFuncsNamespace(f)