tpl/strings: Make it a package that stands on its own

See #3042

tpl/strings/init.go

@@ -0,0 +1,78 @@
+// 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 strings
+
+import (
+	"github.com/spf13/hugo/deps"
+	"github.com/spf13/hugo/tpl/internal"
+)
+
+const name = "strings"
+
+func init() {
+	f := func(d *deps.Deps) *internal.TemplateFuncsNamespace {
+		ctx := New(d)
+
+		examples := [][2]string{
+			{`{{chomp "<p>Blockhead</p>\n" }}`, `<p>Blockhead</p>`},
+			{
+				`{{ findRE "[G|g]o" "Hugo is a static side generator written in Go." "1" }}`,
+				`[go]`},
+			{`{{ hasPrefix "Hugo" "Hu" }}`, `true`},
+			{`{{ hasPrefix "Hugo" "Fu" }}`, `false`},
+			{`{{lower "BatMan"}}`, `batman`},
+			{
+				`{{ replace "Batman and Robin" "Robin" "Catwoman" }}`,
+				`Batman and Catwoman`},
+			{
+				`{{ "http://gohugo.io/docs" | replaceRE "^https?://([^/]+).*" "$1" }}`,
+				`gohugo.io`},
+			{`{{slicestr "BatMan" 0 3}}`, `Bat`},
+			{`{{slicestr "BatMan" 3}}`, `Man`},
+			{`{{substr "BatMan" 0 -3}}`, `Bat`},
+			{`{{substr "BatMan" 3 3}}`, `Man`},
+			{`{{title "Bat man"}}`, `Bat Man`},
+			{`{{ trim "++Batman--" "+-" }}`, `Batman`},
+			{`{{ "this is a very long text" | truncate 10 " ..." }}`, `this is a ...`},
+			{`{{ "With [Markdown](/markdown) inside." | markdownify | truncate 14 }}`, `With <a href="/markdown">Markdown …</a>`},
+			{`{{upper "BatMan"}}`, `BATMAN`},
+		}
+
+		return &internal.TemplateFuncsNamespace{
+			Name:    name,
+			Context: func() interface{} { return ctx },
+			Aliases: map[string]interface{}{
+				"chomp":      ctx.Chomp,
+				"countrunes": ctx.CountRunes,
+				"countwords": ctx.CountWords,
+				"findRE":     ctx.FindRE,
+				"hasPrefix":  ctx.HasPrefix,
+				"lower":      ctx.ToLower,
+				"replace":    ctx.Replace,
+				"replaceRE":  ctx.ReplaceRE,
+				"slicestr":   ctx.SliceString,
+				"split":      ctx.Split,
+				"substr":     ctx.Substr,
+				"title":      ctx.Title,
+				"trim":       ctx.Trim,
+				"truncate":   ctx.Truncate,
+				"upper":      ctx.ToUpper,
+			},
+			Examples: examples,
+		}
+
+	}
+
+	internal.AddTemplateFuncsNamespace(f)
+}