mirror of
https://github.com/facundoolano/jorge.git
synced 2024-12-26 21:58:51 +01:00
93 lines
2.1 KiB
Go
93 lines
2.1 KiB
Go
package site
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import (
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"bytes"
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"io"
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"golang.org/x/net/html"
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)
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// Find the first p tag in the given html document and return its text content.
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func ExtractFirstParagraph(htmlReader io.Reader) string {
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html, err := html.Parse(htmlReader)
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if err != nil {
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return ""
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}
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ptag := findFirstElement(html, "p")
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if ptag == nil {
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return ""
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}
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return getTextContent(ptag)
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}
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// Inject a <script> tag with the given JavaScript code into provided the HTML document
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// and return the updated document as a new io.Reader
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func InjectScript(htmlReader io.Reader, jsCode string) (io.Reader, error) {
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doc, err := html.Parse(htmlReader)
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if err != nil {
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return nil, err
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}
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scriptNode := &html.Node{
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Type: html.ElementNode,
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Data: "script",
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Attr: []html.Attribute{
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{Key: "type", Val: "text/javascript"},
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},
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}
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// insert the script code inside the script tag
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scriptTextNode := &html.Node{
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Type: html.TextNode,
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Data: jsCode,
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}
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scriptNode.AppendChild(scriptTextNode)
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head := findFirstElement(doc, "head")
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if head == nil {
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// If <head> element not found, create one and append it to the document
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head = &html.Node{
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Type: html.ElementNode,
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Data: "head",
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}
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doc.InsertBefore(head, doc.FirstChild)
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}
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// Append the <script> element to the <head> element
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head.AppendChild(scriptNode)
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// Serialize the modified HTML document to a buffer
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var buf bytes.Buffer
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if err := html.Render(&buf, doc); err != nil {
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return nil, err
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}
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// Return a reader for the modified HTML content
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return &buf, nil
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}
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// Finds the first occurrence of the specified element in the HTML document
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func findFirstElement(n *html.Node, tagName string) *html.Node {
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if n.Type == html.ElementNode && n.Data == tagName {
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return n
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}
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for c := n.FirstChild; c != nil; c = c.NextSibling {
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if element := findFirstElement(c, tagName); element != nil {
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return element
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}
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}
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return nil
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}
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// Finds the <head> element in the HTML document
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func getTextContent(node *html.Node) string {
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var textContent string
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if node.Type == html.TextNode {
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textContent = node.Data
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}
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for c := node.FirstChild; c != nil; c = c.NextSibling {
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textContent += getTextContent(c)
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}
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return textContent
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}
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