tpl/partials: Add templates.Exists

Fixes #5010

diff --git a/tpl/templates/init.go b/tpl/templates/init.go
new file mode 100644 (file)
index 0000000..a68809e
--- /dev/null
+++ b/tpl/templates/init.go
@@ -0,0 +1,44 @@
+// Copyright 2018 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 partials
+
+import (
+       "github.com/gohugoio/hugo/deps"
+       "github.com/gohugoio/hugo/tpl/internal"
+)
+
+const name = "templates"
+
+func init() {
+       f := func(d *deps.Deps) *internal.TemplateFuncsNamespace {
+               ctx := New(d)
+
+               ns := &internal.TemplateFuncsNamespace{
+                       Name:    name,
+                       Context: func(args ...interface{}) interface{} { return ctx },
+               }
+
+               ns.AddMethodMapping(ctx.Exists,
+                       nil,
+                       [][2]string{{`{{ if (templates.Exists "partials/header.html") }}Yes!{{ end }}`, `Yes!`},
+                               {`{{ if not (templates.Exists "partials/doesnotexist.html") }}No!{{ end }}`, `No!`},
+                       },
+               )
+
+               return ns
+
+       }
+
+       internal.AddTemplateFuncsNamespace(f)
+}

diff --git a/tpl/templates/init_test.go b/tpl/templates/init_test.go
new file mode 100644 (file)
index 0000000..d833cdd
--- /dev/null
+++ b/tpl/templates/init_test.go
@@ -0,0 +1,38 @@
+// Copyright 2018 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 partials
+
+import (
+       "testing"
+
+       "github.com/gohugoio/hugo/deps"
+       "github.com/gohugoio/hugo/tpl/internal"
+       "github.com/stretchr/testify/require"
+)
+
+func TestInit(t *testing.T) {
+       var found bool
+       var ns *internal.TemplateFuncsNamespace
+
+       for _, nsf := range internal.TemplateFuncsNamespaceRegistry {
+               ns = nsf(&deps.Deps{})
+               if ns.Name == name {
+                       found = true
+                       break
+               }
+       }
+
+       require.True(t, found)
+       require.IsType(t, &Namespace{}, ns.Context())
+}

diff --git a/tpl/templates/templates.go b/tpl/templates/templates.go
new file mode 100644 (file)
index 0000000..7a69e28
--- /dev/null
+++ b/tpl/templates/templates.go
@@ -0,0 +1,39 @@
+// Copyright 2018 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 partials
+
+import (
+       "github.com/gohugoio/hugo/deps"
+)
+
+// New returns a new instance of the templates-namespaced template functions.
+func New(deps *deps.Deps) *Namespace {
+       return &Namespace{
+               deps: deps,
+       }
+}
+
+// Namespace provides template functions for the "templates" namespace.
+type Namespace struct {
+       deps *deps.Deps
+}
+
+// Exists returns whether the template with the given name exists.
+// Note that this is the Unix-styled relative path including filename suffix,
+// e.g. partials/header.html
+func (ns *Namespace) Exists(name string) bool {
+       _, found := ns.deps.Tmpl.Lookup(name)
+       return found
+
+}

diff --git a/tpl/tplimpl/template_funcs.go b/tpl/tplimpl/template_funcs.go
index f1ed7f36ff0c6f9303b0f9efa43c77dc1356df2b..27ffcd97a75e3ef7d06ae857afc0e82d42547b73 100644 (file)
--- a/tpl/tplimpl/template_funcs.go
+++ b/tpl/tplimpl/template_funcs.go
@@ -40,6 +40,7 @@ import (
        _ "github.com/gohugoio/hugo/tpl/resources"
        _ "github.com/gohugoio/hugo/tpl/safe"
        _ "github.com/gohugoio/hugo/tpl/strings"
+       _ "github.com/gohugoio/hugo/tpl/templates"
        _ "github.com/gohugoio/hugo/tpl/time"
        _ "github.com/gohugoio/hugo/tpl/transform"
        _ "github.com/gohugoio/hugo/tpl/urls"