mirror of
https://github.com/gohugoio/hugo.git
synced 2024-11-07 20:30:36 -05:00
02eaddc2fb
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
73 lines
2.1 KiB
Go
73 lines
2.1 KiB
Go
// Copyright 2019 The Hugo Authors. All rights reserved.
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// The functions in this file is based on the Go source code, copyright
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// The Go Authors and governed by a BSD-style license.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Package compare provides template functions for comparing values.
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package compare
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import (
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"reflect"
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"github.com/gohugoio/hugo/common/hreflect"
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)
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// Boolean logic, based on:
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// https://github.com/golang/go/blob/178a2c42254166cffed1b25fb1d3c7a5727cada6/src/text/template/funcs.go#L302
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func truth(arg reflect.Value) bool {
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return hreflect.IsTruthfulValue(arg)
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}
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// getIf will return the given arg if it is considered truthful, else an empty string.
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func (*Namespace) getIf(arg reflect.Value) reflect.Value {
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if truth(arg) {
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return arg
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}
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return reflect.ValueOf("")
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}
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// And computes the Boolean AND of its arguments, returning
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// the first false argument it encounters, or the last argument.
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func (*Namespace) And(arg0 reflect.Value, args ...reflect.Value) reflect.Value {
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if !truth(arg0) {
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return arg0
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}
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for i := range args {
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arg0 = args[i]
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if !truth(arg0) {
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break
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}
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}
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return arg0
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}
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// Or computes the Boolean OR of its arguments, returning
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// the first true argument it encounters, or the last argument.
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func (*Namespace) Or(arg0 reflect.Value, args ...reflect.Value) reflect.Value {
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if truth(arg0) {
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return arg0
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}
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for i := range args {
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arg0 = args[i]
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if truth(arg0) {
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break
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}
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}
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return arg0
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}
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// Not returns the Boolean negation of its argument.
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func (*Namespace) Not(arg reflect.Value) bool {
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return !truth(arg)
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}
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