mirror of
https://github.com/Luzifer/go-latestver.git
synced 2024-11-08 23:20:03 +00:00
98 lines
3 KiB
Go
98 lines
3 KiB
Go
package fetcher
|
|
|
|
import (
|
|
"context"
|
|
"regexp"
|
|
"time"
|
|
|
|
"github.com/antchfx/htmlquery"
|
|
"github.com/antchfx/xpath"
|
|
"github.com/pkg/errors"
|
|
"golang.org/x/net/html"
|
|
|
|
"github.com/Luzifer/go-latestver/internal/database"
|
|
"github.com/Luzifer/go_helpers/v2/fieldcollection"
|
|
)
|
|
|
|
/*
|
|
* @module html
|
|
* @module_desc Downloads website, selects text-node using XPath and optionally applies custom regular expression
|
|
*/
|
|
|
|
var htmlFetcherDefaultRegex = `(v?(?:[0-9]+\.?){2,})`
|
|
|
|
type (
|
|
// HTMLFetcher implements the fetcher interface to monitor versions on websites by xpath queries
|
|
HTMLFetcher struct{}
|
|
)
|
|
|
|
func init() { registerFetcher("html", func() Fetcher { return &HTMLFetcher{} }) }
|
|
|
|
// FetchVersion retrieves the latest version for the catalog entry
|
|
func (HTMLFetcher) FetchVersion(_ context.Context, attrs *fieldcollection.FieldCollection) (string, time.Time, error) {
|
|
doc, err := htmlquery.LoadURL(attrs.MustString("url", nil))
|
|
if err != nil {
|
|
return "", time.Time{}, errors.Wrap(err, "loading URL")
|
|
}
|
|
|
|
node, err := htmlquery.Query(doc, attrs.MustString("xpath", nil))
|
|
if err != nil {
|
|
return "", time.Time{}, errors.Wrap(err, "querying xpath")
|
|
}
|
|
|
|
if node == nil {
|
|
return "", time.Time{}, errors.New("xpath expression lead to nil-node")
|
|
}
|
|
|
|
if node.Type == html.ElementNode && node.FirstChild != nil && node.FirstChild.Type == html.TextNode {
|
|
node = node.FirstChild
|
|
}
|
|
|
|
if node.Type != html.TextNode {
|
|
return "", time.Time{}, errors.Errorf("xpath expression lead to unexpected node type: %d", node.Type)
|
|
}
|
|
|
|
match := regexp.MustCompile(attrs.MustString("regex", &htmlFetcherDefaultRegex)).FindStringSubmatch(node.Data)
|
|
if len(match) < 2 { //nolint:gomnd // Simple count of fields, no need for constant
|
|
return "", time.Time{}, errors.New("regular expression did not yield version")
|
|
}
|
|
|
|
return match[1], time.Now(), nil
|
|
}
|
|
|
|
// Links retrieves a collection of links for the fetcher
|
|
func (HTMLFetcher) Links(attrs *fieldcollection.FieldCollection) []database.CatalogLink {
|
|
return []database.CatalogLink{
|
|
{
|
|
IconClass: "fas fa-globe",
|
|
Name: "Website",
|
|
URL: attrs.MustString("url", nil),
|
|
},
|
|
}
|
|
}
|
|
|
|
// Validate validates the configuration given to the fetcher
|
|
func (HTMLFetcher) Validate(attrs *fieldcollection.FieldCollection) error {
|
|
// @attr url required string "" URL to fetch the HTML from
|
|
if v, err := attrs.String("url"); err != nil || v == "" {
|
|
return errors.New("url is expected to be non-empty string")
|
|
}
|
|
|
|
// @attr xpath required string "" XPath expression leading to the text-node containing the version
|
|
if v, err := attrs.String("xpath"); err != nil || v == "" {
|
|
return errors.New("xpath is expected to be non-empty string")
|
|
}
|
|
|
|
if _, err := xpath.Compile(attrs.MustString("xpath", nil)); err != nil {
|
|
return errors.Wrap(err, "compiling xpath expression")
|
|
}
|
|
|
|
// @attr regex optional string "(v?(?:[0-9]+\.?){2,})" Regular expression to apply to the text from the XPath expression
|
|
if attrs.CanString("regex") {
|
|
if _, err := regexp.Compile(attrs.MustString("regex", nil)); err != nil {
|
|
return errors.Wrap(err, "invalid regex given")
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|