How to generate and serve HTML files with dynamically generated content in Go?

To generate and serve HTML files with dynamically generated content in Go, you can use the "html/template" package to define templates and populate them with data.

Here's a step-by-step guide:

Import the necessary packages:

import (
    "html/template"
    "net/http"
)

Define your HTML template:

const htmlTemplate = `
<!DOCTYPE html>
<html>
<head>
    <title>{{.Title}}</title>
</head>
<body>
    <h1>{{.Heading}}</h1>
    {{range .Items}}
    <div>{{.}}</div>
    {{end}}
</body>
</html>
`

In this example, the template contains placeholders like {{.Title}}, {{.Heading}}, and {{.Items}} which will be replaced with actual data.

Create a handler function to process the HTTP request and render the template:

func handler(w http.ResponseWriter, r *http.Request) {
    data := struct {
        Title   string
        Heading string
        Items   []string
    }{
        Title:   "Dynamic Content",
        Heading: "List of Items",
        Items:   []string{"Item 1", "Item 2", "Item 3"},
    }

    t := template.Must(template.New("html").Parse(htmlTemplate))
    // You can check for errors in template parsing here

    err := t.Execute(w, data)
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
    }
}

In this example, we create a struct data to hold the data needed by the template. We populate the struct with the required values. Then, we create a new template using template.New("html") and parse the HTML template using t.Parse(htmlTemplate). Finally, we use t.Execute(w, data) to render the template with the provided data and write the result to the response writer w.

func main() {
    http.HandleFunc("/dynamic", handler) // Register the handler to the "/dynamic" route

    // Start the server
    err := http.ListenAndServe(":8080", nil)
    if err != nil {
        log.Fatal(err)
    }
}

Now, when you access http://localhost:8080/dynamic in your browser, it will serve the dynamically generated HTML file with the provided content.

Note: Remember to replace the values and structure of the template and data according to your specific needs.