resources: Move resource interfaces into its own package

2 files changed, 229 insertions, 0 deletions

diff --git a/resources/resource/resources.go b/resources/resource/resources.go
new file mode 100644
index 000000000..5c661c24e
--- /dev/null
+++ b/resources/resource/resources.go
@@ -0,0 +1,123 @@
+// Copyright 2019 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 resource
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/gohugoio/hugo/resources/internal"
+)
+
+// Resources represents a slice of resources, which can be a mix of different types.
+// I.e. both pages and images etc.
+type Resources []Resource
+
+// ResourcesConverter converts a given slice of Resource objects to Resources.
+type ResourcesConverter interface {
+	ToResources() Resources
+}
+
+// ByType returns resources of a given resource type (ie. "image").
+func (r Resources) ByType(tp string) Resources {
+	var filtered Resources
+
+	for _, resource := range r {
+		if resource.ResourceType() == tp {
+			filtered = append(filtered, resource)
+		}
+	}
+	return filtered
+}
+
+// GetMatch finds the first Resource matching the given pattern, or nil if none found.
+// See Match for a more complete explanation about the rules used.
+func (r Resources) GetMatch(pattern string) Resource {
+	g, err := internal.GetGlob(pattern)
+	if err != nil {
+		return nil
+	}
+
+	for _, resource := range r {
+		if g.Match(strings.ToLower(resource.Name())) {
+			return resource
+		}
+	}
+
+	return nil
+}
+
+// Match gets all resources matching the given base filename prefix, e.g
+// "*.png" will match all png files. The "*" does not match path delimiters (/),
+// so if you organize your resources in sub-folders, you need to be explicit about it, e.g.:
+// "images/*.png". To match any PNG image anywhere in the bundle you can do "**.png", and
+// to match all PNG images below the images folder, use "images/**.jpg".
+// The matching is case insensitive.
+// Match matches by using the value of Resource.Name, which, by default, is a filename with
+// path relative to the bundle root with Unix style slashes (/) and no leading slash, e.g. "images/logo.png".
+// See https://github.com/gobwas/glob for the full rules set.
+func (r Resources) Match(pattern string) Resources {
+	g, err := internal.GetGlob(pattern)
+	if err != nil {
+		return nil
+	}
+
+	var matches Resources
+	for _, resource := range r {
+		if g.Match(strings.ToLower(resource.Name())) {
+			matches = append(matches, resource)
+		}
+	}
+	return matches
+}
+
+type translatedResource interface {
+	TranslationKey() string
+}
+
+// MergeByLanguage adds missing translations in r1 from r2.
+func (r Resources) MergeByLanguage(r2 Resources) Resources {
+	result := append(Resources(nil), r...)
+	m := make(map[string]bool)
+	for _, rr := range r {
+		if translated, ok := rr.(translatedResource); ok {
+			m[translated.TranslationKey()] = true
+		}
+	}
+
+	for _, rr := range r2 {
+		if translated, ok := rr.(translatedResource); ok {
+			if _, found := m[translated.TranslationKey()]; !found {
+				result = append(result, rr)
+			}
+		}
+	}
+	return result
+}
+
+// MergeByLanguageInterface is the generic version of MergeByLanguage. It
+// is here just so it can be called from the tpl package.
+func (r Resources) MergeByLanguageInterface(in interface{}) (interface{}, error) {
+	r2, ok := in.(Resources)
+	if !ok {
+		return nil, fmt.Errorf("%T cannot be merged by language", in)
+	}
+	return r.MergeByLanguage(r2), nil
+}
+
+// Source is an internal template and not meant for use in the templates. It
+// may change without notice.
+type Source interface {
+	Publish() error
+}
diff --git a/resources/resource/resourcetypes.go b/resources/resource/resourcetypes.go
new file mode 100644
index 000000000..120d753e4
--- /dev/null
+++ b/resources/resource/resourcetypes.go
@@ -0,0 +1,106 @@
+// Copyright 2019 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 resource
+
+import (
+	"github.com/gohugoio/hugo/media"
+
+	"github.com/gohugoio/hugo/common/hugio"
+)
+
+// Cloner is an internal template and not meant for use in the templates. It
+// may change without notice.
+type Cloner interface {
+	WithNewBase(base string) Resource
+}
+
+// Resource represents a linkable resource, i.e. a content page, image etc.
+type Resource interface {
+	resourceBase
+
+	// Permalink represents the absolute link to this resource.
+	Permalink() string
+
+	// RelPermalink represents the host relative link to this resource.
+	RelPermalink() string
+
+	// ResourceType is the resource type. For most file types, this is the main
+	// part of the MIME type, e.g. "image", "application", "text" etc.
+	// For content pages, this value is "page".
+	ResourceType() string
+
+	// Name is the logical name of this resource. This can be set in the front matter
+	// metadata for this resource. If not set, Hugo will assign a value.
+	// This will in most cases be the base filename.
+	// So, for the image "/some/path/sunset.jpg" this will be "sunset.jpg".
+	// The value returned by this method will be used in the GetByPrefix and ByPrefix methods
+	// on Resources.
+	Name() string
+
+	// Title returns the title if set in front matter. For content pages, this will be the expected value.
+	Title() string
+
+	// Resource specific data set by Hugo.
+	// One example would be.Data.Digest for fingerprinted resources.
+	Data() interface{}
+
+	// Params set in front matter for this resource.
+	Params() map[string]interface{}
+}
+
+// resourceBase pulls out the minimal set of operations to define a Resource,
+// to simplify testing etc.
+type resourceBase interface {
+	// MediaType is this resource's MIME type.
+	MediaType() media.Type
+}
+
+// ResourcesLanguageMerger describes an interface for merging resources from a
+// different language.
+type ResourcesLanguageMerger interface {
+	MergeByLanguage(other Resources) Resources
+	// Needed for integration with the tpl package.
+	MergeByLanguageInterface(other interface{}) (interface{}, error)
+}
+
+// Identifier identifies a resource.
+type Identifier interface {
+	Key() string
+}
+
+// ContentResource represents a Resource that provides a way to get to its content.
+// Most Resource types in Hugo implements this interface, including Page.
+// This should be used with care, as it will read the file content into memory, but it
+// should be cached as effectively as possible by the implementation.
+type ContentResource interface {
+	resourceBase
+
+	// Content returns this resource's content. It will be equivalent to reading the content
+	// that RelPermalink points to in the published folder.
+	// The return type will be contextual, and should be what you would expect:
+	// * Page: template.HTML
+	// * JSON: String
+	// * Etc.
+	Content() (interface{}, error)
+}
+
+// OpenReadSeekCloser allows setting some other way (than reading from a filesystem)
+// to open or create a ReadSeekCloser.
+type OpenReadSeekCloser func() (hugio.ReadSeekCloser, error)
+
+// ReadSeekCloserResource is a Resource that supports loading its content.
+type ReadSeekCloserResource interface {
+	resourceBase
+	ReadSeekCloser() (hugio.ReadSeekCloser, error)
+}