webinfo -- Extract metadata and structured information from web pages

webinfo is a small Go module that extracts common metadata from web pages and provides utilities to download representative images and create thumbnails.

Quick overview

• Package: webinfo
• Repository: github.com/goark/webinfo
• Purpose: fetch page metadata (title, description, canonical, image, etc.) and download images

Features

• Fetch page metadata with Fetch (handles encodings and meta tag precedence).
• Download an image referenced by Webinfo.ImageURL using (*Webinfo).DownloadImage.
• Create a thumbnail from the referenced image using (*Webinfo).DownloadThumbnail.

Install

Use Go modules (Go 1.25+ as used by the project):

go get github.com/goark/webinfo@latest

Basic usage

Example showing fetch and download thumbnail (error handling omitted for brevity):

package main

import (
    "context"
    "fmt"
    "github.com/goark/webinfo"
)

func main() {
    ctx := context.Background()
    // Fetch metadata for a page (empty UA uses default)
    info, err := webinfo.Fetch(ctx, "https://example.com", "")
    if err != nil {
        fmt.Fprintln(os.Stderr, "error fetching webinfo:", err)
        panic(err)
    }

    // Download thumbnail: width 150, to directory "thumbnails", permanent file
    thumbPath, err := info.DownloadThumbnail(ctx, "thumbnails", 150, false)
    if err != nil {
        panic(err)
    }
    fmt.Println("thumbnail saved:", thumbPath)
}

API notes

• Fetch(ctx, url, userAgent) — Parse and extract metadata. Pass an empty userAgent to use the module default.
• (*Webinfo).DownloadImage(ctx, destDir, temporary) — Download the image in Webinfo.ImageURL and save it. If temporary is true (or destDir is empty), a temporary file is created.
• (*Webinfo).DownloadThumbnail(ctx, destDir, width, temporary) — Download the referenced image and produce a thumbnail resized to width pixels (height is preserved by aspect ratio). If destDir is empty the method creates a temporary file; when temporary is false the thumbnail file is named based on the original image name with -thums appended before the extension.

Error handling

The package uses github.com/goark/errs for wrapping errors with contextual keys (e.g. url, path, dir). Callers should inspect returned errors accordingly.

Tests & development

• Run all tests: go test ./...
• The repository includes Taskfile.yml tasks for common workflows; see that file for CI/test commands.

Modules Requirement Graph