// 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 livereloadinject import ( "bytes" "fmt" "github.com/gohugoio/hugo/helpers" "github.com/gohugoio/hugo/transform" ) type tag struct { markup []byte appendScript bool } var tags = []tag{ tag{markup: []byte(""), appendScript: true}, tag{markup: []byte(""), appendScript: true}, tag{markup: []byte("")}, tag{markup: []byte("")}, } // New creates a function that can be used // to inject a script tag for the livereload JavaScript in a HTML document. func New(port int) transform.Transformer { return func(ft transform.FromTo) error { b := ft.From().Bytes() var idx = -1 var match tag // We used to insert the livereload script right before the closing body. // This does not work when combined with tools such as Turbolinks. // So we try to inject the script as early as possible. for _, t := range tags { idx = bytes.Index(b, t.markup) if idx != -1 { match = t break } } c := make([]byte, len(b)) copy(c, b) if idx == -1 { _, err := ft.To().Write(c) return err } script := []byte(fmt.Sprintf(``, port)) i := idx if match.appendScript { i += len(match.markup) } c = append(c[:i], append(script, c[i:]...)...) if _, err := ft.To().Write(c); err != nil { helpers.DistinctWarnLog.Println("Failed to inject LiveReload script:", err) } return nil } }