github.com/olliephillips/hugo@v0.42.2/transform/hugogeneratorinject.go (about)

     1  // Copyright 2016 The Hugo Authors. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package transform
    15  
    16  import (
    17  	"bytes"
    18  	"fmt"
    19  	"regexp"
    20  
    21  	"github.com/gohugoio/hugo/helpers"
    22  )
    23  
    24  var metaTagsCheck = regexp.MustCompile(`(?i)<meta\s+name=['|"]?generator['|"]?`)
    25  var hugoGeneratorTag = fmt.Sprintf(`<meta name="generator" content="Hugo %s" />`, helpers.CurrentHugoVersion)
    26  
    27  // HugoGeneratorInject injects a meta generator tag for Hugo if none present.
    28  func HugoGeneratorInject(ct contentTransformer) {
    29  	if metaTagsCheck.Match(ct.Content()) {
    30  		if _, err := ct.Write(ct.Content()); err != nil {
    31  			helpers.DistinctWarnLog.Println("Failed to inject Hugo generator tag:", err)
    32  		}
    33  		return
    34  	}
    35  
    36  	head := "<head>"
    37  	replace := []byte(fmt.Sprintf("%s\n\t%s", head, hugoGeneratorTag))
    38  	newcontent := bytes.Replace(ct.Content(), []byte(head), replace, 1)
    39  
    40  	if len(newcontent) == len(ct.Content()) {
    41  		head := "<HEAD>"
    42  		replace := []byte(fmt.Sprintf("%s\n\t%s", head, hugoGeneratorTag))
    43  		newcontent = bytes.Replace(ct.Content(), []byte(head), replace, 1)
    44  	}
    45  
    46  	if _, err := ct.Write(newcontent); err != nil {
    47  		helpers.DistinctWarnLog.Println("Failed to inject Hugo generator tag:", err)
    48  	}
    49  
    50  }