5 files changed, 148 insertions, 11 deletions
diff --git a/tpl/openapi/openapi3/init.go b/tpl/openapi/openapi3/init.go
new file mode 100644
index 000000000..1e1a4ae05
--- /dev/null
+++ b/tpl/openapi/openapi3/init.go
@@ -0,0 +1,42 @@
+// Copyright 2020 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 openapi3
+
+import (
+	"github.com/gohugoio/hugo/deps"
+	"github.com/gohugoio/hugo/tpl/internal"
+)
+
+const name = "openapi3"
+
+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.Unmarshal,
+			nil,
+			[][2]string{},
+		)
+
+		return ns
+
+	}
+
+	internal.AddTemplateFuncsNamespace(f)
+}
diff --git a/tpl/openapi/openapi3/openapi3.go b/tpl/openapi/openapi3/openapi3.go
new file mode 100644
index 000000000..7dfd2f6a7
--- /dev/null
+++ b/tpl/openapi/openapi3/openapi3.go
@@ -0,0 +1,97 @@
+// Copyright 2020 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 openapi3
+
+import (
+	"io/ioutil"
+
+	gyaml "github.com/ghodss/yaml"
+
+	"github.com/pkg/errors"
+
+	kopenapi3 "github.com/getkin/kin-openapi/openapi3"
+	"github.com/gohugoio/hugo/cache/namedmemcache"
+	"github.com/gohugoio/hugo/deps"
+	"github.com/gohugoio/hugo/parser/metadecoders"
+	"github.com/gohugoio/hugo/resources/resource"
+)
+
+// New returns a new instance of the openapi3-namespaced template functions.
+func New(deps *deps.Deps) *Namespace {
+	// TODO1 consolidate when merging that "other branch" -- but be aware of the keys.
+	cache := namedmemcache.New()
+	deps.BuildStartListeners.Add(
+		func() {
+			cache.Clear()
+		})
+
+	return &Namespace{
+		cache: cache,
+		deps:  deps,
+	}
+}
+
+// Namespace provides template functions for the "openapi3".
+type Namespace struct {
+	cache *namedmemcache.Cache
+	deps  *deps.Deps
+}
+
+func (ns *Namespace) Unmarshal(r resource.UnmarshableResource) (*kopenapi3.Swagger, error) {
+
+	key := r.Key()
+	if key == "" {
+		return nil, errors.New("no Key set in Resource")
+	}
+
+	v, err := ns.cache.GetOrCreate(key, func() (interface{}, error) {
+		f := metadecoders.FormatFromMediaType(r.MediaType())
+		if f == "" {
+			return nil, errors.Errorf("MIME %q not supported", r.MediaType())
+		}
+
+		reader, err := r.ReadSeekCloser()
+		if err != nil {
+			return nil, err
+		}
+		defer reader.Close()
+
+		b, err := ioutil.ReadAll(reader)
+		if err != nil {
+			return nil, err
+		}
+
+		s := &kopenapi3.Swagger{}
+		switch f {
+		case metadecoders.YAML:
+			err = gyaml.Unmarshal(b, s)
+		default:
+			err = metadecoders.Default.UnmarshalTo(b, f, s)
+		}
+		if err != nil {
+			return nil, err
+		}
+
+		err = kopenapi3.NewSwaggerLoader().ResolveRefsIn(s, nil)
+
+		return s, err
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return v.(*kopenapi3.Swagger), nil
+
+}
diff --git a/tpl/tplimpl/template_funcs.go b/tpl/tplimpl/template_funcs.go
index ccf33d8ba..9141de3f1 100644
--- a/tpl/tplimpl/template_funcs.go
+++ b/tpl/tplimpl/template_funcs.go
@@ -44,6 +44,7 @@ import (
 	_ "github.com/gohugoio/hugo/tpl/inflect"
 	_ "github.com/gohugoio/hugo/tpl/lang"
 	_ "github.com/gohugoio/hugo/tpl/math"
+	_ "github.com/gohugoio/hugo/tpl/openapi/openapi3"
 	_ "github.com/gohugoio/hugo/tpl/os"
 	_ "github.com/gohugoio/hugo/tpl/partials"
 	_ "github.com/gohugoio/hugo/tpl/path"
diff --git a/tpl/transform/unmarshal.go b/tpl/transform/unmarshal.go
index da06b6aa1..b606c870a 100644
--- a/tpl/transform/unmarshal.go
+++ b/tpl/transform/unmarshal.go
@@ -17,17 +17,20 @@ import (
 	"io/ioutil"
 	"strings"
 
+	"github.com/gohugoio/hugo/resources/resource"
+
+	"github.com/gohugoio/hugo/common/types"
+
 	"github.com/mitchellh/mapstructure"
 
 	"github.com/gohugoio/hugo/helpers"
 	"github.com/gohugoio/hugo/parser/metadecoders"
-	"github.com/gohugoio/hugo/resources/resource"
 	"github.com/pkg/errors"
 
 	"github.com/spf13/cast"
 )
 
-// Unmarshal unmarshals the data given, which can be either a string
+// Unmarshal unmarshals the data given, which can be either a string, json.RawMessage
 // or a Resource. Supported formats are JSON, TOML, YAML, and CSV.
 // You can optionally provide an options map as the first argument.
 func (ns *Namespace) Unmarshal(args ...interface{}) (interface{}, error) {
@@ -55,7 +58,7 @@ func (ns *Namespace) Unmarshal(args ...interface{}) (interface{}, error) {
 		}
 	}
 
-	if r, ok := data.(unmarshableResource); ok {
+	if r, ok := data.(resource.UnmarshableResource); ok {
 		key := r.Key()
 
 		if key == "" {
@@ -87,7 +90,7 @@ func (ns *Namespace) Unmarshal(args ...interface{}) (interface{}, error) {
 		})
 	}
 
-	dataStr, err := cast.ToStringE(data)
+	dataStr, err := types.ToStringE(data)
 	if err != nil {
 		return nil, errors.Errorf("type %T not supported", data)
 	}
@@ -104,12 +107,6 @@ func (ns *Namespace) Unmarshal(args ...interface{}) (interface{}, error) {
 	})
 }
 
-// All the relevant resources implements this interface.
-type unmarshableResource interface {
-	resource.ReadSeekCloserResource
-	resource.Identifier
-}
-
 func decodeDecoder(m map[string]interface{}) (metadecoders.Decoder, error) {
 	opts := metadecoders.Default
 
diff --git a/tpl/transform/unmarshal_test.go b/tpl/transform/unmarshal_test.go
index 7b0caa07f..183bdefd5 100644
--- a/tpl/transform/unmarshal_test.go
+++ b/tpl/transform/unmarshal_test.go
@@ -20,11 +20,11 @@ import (
 	"testing"
 
 	"github.com/gohugoio/hugo/common/hugio"
+	"github.com/gohugoio/hugo/resources/resource"
 
 	"github.com/gohugoio/hugo/media"
 
 	qt "github.com/frankban/quicktest"
-	"github.com/gohugoio/hugo/resources/resource"
 	"github.com/spf13/viper"
 )