Add custom protocol support in Permalink

helpers/baseURL.go

@@ -0,0 +1,74 @@
+// 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 helpers
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+// A BaseURL in Hugo is normally on the form scheme://path, but the
+// form scheme: is also valid (mailto:hugo@rules.com).
+type BaseURL struct {
+	url    *url.URL
+	urlStr string
+}
+
+func (b BaseURL) String() string {
+	return b.urlStr
+}
+
+// Protocol is normaly on the form "scheme://", i.e. "webcal://".
+func (b BaseURL) WithProtocol(protocol string) (string, error) {
+	u := b.URL()
+
+	scheme := protocol
+	isFullProtocol := strings.HasSuffix(scheme, "://")
+	isOpaqueProtocol := strings.HasSuffix(scheme, ":")
+
+	if isFullProtocol {
+		scheme = strings.TrimSuffix(scheme, "://")
+	} else if isOpaqueProtocol {
+		scheme = strings.TrimSuffix(scheme, ":")
+	}
+
+	u.Scheme = scheme
+
+	if isFullProtocol && u.Opaque != "" {
+		u.Opaque = "//" + u.Opaque
+	} else if isOpaqueProtocol && u.Opaque == "" {
+		return "", fmt.Errorf("Cannot determine BaseURL for protocol %q", protocol)
+	}
+
+	return u.String(), nil
+}
+
+func (b BaseURL) URL() *url.URL {
+	// create a copy as it will be modified.
+	c := *b.url
+	return &c
+}
+
+func newBaseURLFromString(b string) (BaseURL, error) {
+	var result BaseURL
+
+	base, err := url.Parse(b)
+	if err != nil {
+		return result, err
+	}
+
+	// TODO(bep) output consider saving original URL?
+	return BaseURL{url: base, urlStr: base.String()}, nil
+}