hugo/tpl/compare/init.go
Bjørn Erik Pedersen 02eaddc2fb
tpl/tplimpl: Fix template truth logic
Before this commit, due to a bug in Go's `text/template` package, this would print different output for typed nil interface values:

```
{{ if .AuthenticatedUser }}User is authenticated!{{ else }}{{ end }}
{{ if not .AuthenticatedUser }}{{ else }}}User is authenticated!{{ end }}
```

This commit works around this by wrapping every `if` and `with` with a custom `getif` template func with truth logic that matches `not`, `and` and `or`.

Those 3 template funcs from Go's stdlib are now pulled into Hugo's source tree and adjusted to support custom zero values, e.g. types that implement `IsZero`.

This means that you can now do:

```
{{ with .Date }}{{ . }}{{ end }}
```

And it would work as expected.

Fixes #5738
2019-03-06 22:52:38 +01:00

107 lines
2.3 KiB
Go

// Copyright 2017 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package compare
import (
"github.com/gohugoio/hugo/deps"
"github.com/gohugoio/hugo/tpl/internal"
)
const name = "compare"
func init() {
f := func(d *deps.Deps) *internal.TemplateFuncsNamespace {
ctx := New()
ns := &internal.TemplateFuncsNamespace{
Name: name,
Context: func(args ...interface{}) interface{} { return ctx },
}
ns.AddMethodMapping(ctx.Default,
[]string{"default"},
[][2]string{
{`{{ "Hugo Rocks!" | default "Hugo Rules!" }}`, `Hugo Rocks!`},
{`{{ "" | default "Hugo Rules!" }}`, `Hugo Rules!`},
},
)
ns.AddMethodMapping(ctx.Eq,
[]string{"eq"},
[][2]string{
{`{{ if eq .Section "blog" }}current{{ end }}`, `current`},
},
)
ns.AddMethodMapping(ctx.Ge,
[]string{"ge"},
[][2]string{
{`{{ if ge .Hugo.Version "0.36" }}Reasonable new Hugo version!{{ end }}`, `Reasonable new Hugo version!`},
},
)
ns.AddMethodMapping(ctx.Gt,
[]string{"gt"},
[][2]string{},
)
ns.AddMethodMapping(ctx.Le,
[]string{"le"},
[][2]string{},
)
ns.AddMethodMapping(ctx.Lt,
[]string{"lt"},
[][2]string{},
)
ns.AddMethodMapping(ctx.Ne,
[]string{"ne"},
[][2]string{},
)
ns.AddMethodMapping(ctx.And,
[]string{"and"},
[][2]string{},
)
ns.AddMethodMapping(ctx.Or,
[]string{"or"},
[][2]string{},
)
// getif is used internally by Hugo. Do not document.
ns.AddMethodMapping(ctx.getIf,
[]string{"getif"},
[][2]string{},
)
ns.AddMethodMapping(ctx.Not,
[]string{"not"},
[][2]string{},
)
ns.AddMethodMapping(ctx.Conditional,
[]string{"cond"},
[][2]string{
{`{{ cond (eq (add 2 2) 4) "2+2 is 4" "what?" | safeHTML }}`, `2+2 is 4`},
},
)
return ns
}
internal.AddTemplateFuncsNamespace(f)
}