xpath.go

/*
Copyright 2024 The west2-online Authors.

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 jwch

import (
	"regexp"

	"github.com/antchfx/htmlquery"
	"golang.org/x/net/html"
)

// Safely extract data from html node by expression
func safeExtractionFirst(node *html.Node, expr string) string {
	res := htmlquery.FindOne(node, expr)

	if res == nil {
		return htmlquery.OutputHTML(node, false)
	}

	return htmlquery.OutputHTML(res, false)
}

// Safely extract data from html node by expression, return the index-th element(if index is out of range, return the last element)
func safeExtractionValue(node *html.Node, expr string, value string, index int) string {
	res := htmlquery.Find(node, expr)

	if res == nil {
		return ""
	}

	if len(res) <= index {
		return htmlquery.SelectAttr(res[len(res)-1], value)
	}

	return htmlquery.SelectAttr(res[index], value)
}

// Safely extract data by regex
func safeExtractRegex(regex, str string) string {
	res := regexp.MustCompile(regex).FindStringSubmatch(str)

	if len(res) < 2 {
		return ""
	}

	return res[1]
}

func safeExtractHTMLFirst(node *html.Node, expr string) string {
	res := htmlquery.FindOne(node, expr)

	if res == nil {
		return ""
	}

	return htmlquery.OutputHTML(res, false)
}