youtubebeat/vendor/github.com/gocolly/colly/htmlelement.go

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2018-11-18 15:32:28 +01:00
// Copyright 2018 Adam Tauber
//
// 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 colly
import (
"strings"
"github.com/PuerkitoBio/goquery"
"golang.org/x/net/html"
)
// HTMLElement is the representation of a HTML tag.
type HTMLElement struct {
// Name is the name of the tag
Name string
Text string
attributes []html.Attribute
// Request is the request object of the element's HTML document
Request *Request
// Response is the Response object of the element's HTML document
Response *Response
// DOM is the goquery parsed DOM object of the page. DOM is relative
// to the current HTMLElement
DOM *goquery.Selection
// Index stores the position of the current element within all the elements matched by an OnHTML callback
Index int
}
// NewHTMLElementFromSelectionNode creates a HTMLElement from a goquery.Selection Node.
func NewHTMLElementFromSelectionNode(resp *Response, s *goquery.Selection, n *html.Node, idx int) *HTMLElement {
return &HTMLElement{
Name: n.Data,
Request: resp.Request,
Response: resp,
Text: goquery.NewDocumentFromNode(n).Text(),
DOM: s,
Index: idx,
attributes: n.Attr,
}
}
// Attr returns the selected attribute of a HTMLElement or empty string
// if no attribute found
func (h *HTMLElement) Attr(k string) string {
for _, a := range h.attributes {
if a.Key == k {
return a.Val
}
}
return ""
}
// ChildText returns the concatenated and stripped text content of the matching
// elements.
func (h *HTMLElement) ChildText(goquerySelector string) string {
return strings.TrimSpace(h.DOM.Find(goquerySelector).Text())
}
// ChildAttr returns the stripped text content of the first matching
// element's attribute.
func (h *HTMLElement) ChildAttr(goquerySelector, attrName string) string {
if attr, ok := h.DOM.Find(goquerySelector).Attr(attrName); ok {
return strings.TrimSpace(attr)
}
return ""
}
// ChildAttrs returns the stripped text content of all the matching
// element's attributes.
func (h *HTMLElement) ChildAttrs(goquerySelector, attrName string) []string {
var res []string
h.DOM.Find(goquerySelector).Each(func(_ int, s *goquery.Selection) {
if attr, ok := s.Attr(attrName); ok {
res = append(res, strings.TrimSpace(attr))
}
})
return res
}
// ForEach iterates over the elements matched by the first argument
// and calls the callback function on every HTMLElement match.
func (h *HTMLElement) ForEach(goquerySelector string, callback func(int, *HTMLElement)) {
i := 0
h.DOM.Find(goquerySelector).Each(func(_ int, s *goquery.Selection) {
for _, n := range s.Nodes {
callback(i, NewHTMLElementFromSelectionNode(h.Response, s, n, i))
i++
}
})
}
// ForEachWithBreak iterates over the elements matched by the first argument
// and calls the callback function on every HTMLElement match.
// It is identical to ForEach except that it is possible to break
// out of the loop by returning false in the callback function. It returns the
// current Selection object.
func (h *HTMLElement) ForEachWithBreak(goquerySelector string, callback func(int, *HTMLElement) bool) {
i := 0
h.DOM.Find(goquerySelector).EachWithBreak(func(_ int, s *goquery.Selection) bool {
for _, n := range s.Nodes {
if callback(i, NewHTMLElementFromSelectionNode(h.Response, s, n, i)) {
i++
return true
}
}
return false
})
}