ref: 08f48b91d68d3002b887ddf737456ff0cc4e786d
parent: 2fc121ce2308b090ab67cbeb3039c53f5eedaa64
author: Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com>
date: Thu Aug 17 06:24:17 EDT 2017
compare, hugolib, tpl: Add Eqer interface And use it in `eq` and `ne` so `Page` values can be compared directly in the templates without thinking about it being a `Page` or a `PageOutput` wrapper. Fixes #3807
--- /dev/null
+++ b/compare/eq.go
@@ -1,0 +1,21 @@
+// Copyright 2017-present 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
+
+// Eqer can be used to determine if this value is equal to the other.
+// The semantics of equals is that the two value are interchangeable
+// in the Hugo templates.
+type Eqer interface {+ Eq(other interface{}) bool+}
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -38,6 +38,7 @@
"unicode/utf8"
bp "github.com/gohugoio/hugo/bufferpool"
+ "github.com/gohugoio/hugo/compare"
"github.com/gohugoio/hugo/source"
"github.com/spf13/cast"
)
@@ -49,6 +50,10 @@
allKindsInPages = []string{KindPage, KindHome, KindSection, KindTaxonomy, KindTaxonomyTerm} allKinds = append(allKindsInPages, []string{kindRSS, kindSitemap, kindRobotsTXT, kind404}...)+
+ // Assert that it implements the Eqer interface.
+ _ compare.Eqer = (*Page)(nil)
+ _ compare.Eqer = (*PageOutput)(nil)
)
const (
--- a/tpl/compare/compare.go
+++ b/tpl/compare/compare.go
@@ -18,6 +18,8 @@
"reflect"
"strconv"
"time"
+
+ "github.com/gohugoio/hugo/compare"
)
// New returns a new instance of the compare-namespaced template functions.
@@ -85,6 +87,14 @@
// Eq returns the boolean truth of arg1 == arg2.
func (*Namespace) Eq(x, y interface{}) bool {+
+ // hugolib.Page implements compare.Eqer to make Page and PageOutput comparable.
+ if e1, ok := x.(compare.Eqer); ok {+ if e2, ok := y.(compare.Eqer); ok {+ return e1.Eq(e2)
+ }
+ }
+
normalize := func(v interface{}) interface{} {vv := reflect.ValueOf(v)
switch vv.Kind() {--- a/tpl/compare/compare_test.go
+++ b/tpl/compare/compare_test.go
@@ -26,6 +26,25 @@
"github.com/stretchr/testify/require"
)
+type tstEqerType1 string
+type tstEqerType2 string
+
+func (t tstEqerType2) Eq(other interface{}) bool {+ return cast.ToString(t) == cast.ToString(other)
+}
+
+func (t tstEqerType2) String() string {+ return string(t)
+}
+
+func (t tstEqerType1) Eq(other interface{}) bool {+ return cast.ToString(t) == cast.ToString(other)
+}
+
+func (t tstEqerType1) String() string {+ return string(t)
+}
+
type tstCompareType int
const (
@@ -148,6 +167,10 @@
{"a", "a", 0}, {"a", "b", -1}, {"b", "a", 1},+ {tstEqerType1("a"), tstEqerType1("a"), 0},+ {tstEqerType1("a"), tstEqerType2("a"), 0},+ {tstEqerType2("a"), tstEqerType1("a"), 0},+ {tstEqerType2("a"), tstEqerType1("b"), -1}, } {result := funcUnderTest(test.left, test.right)
success := false
--
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