javascript - 从 HTML 元素中提取 href 无法使用 node.js

问题描述

我正在尝试从该网站上抓取数据：https ://www.gelbeseiten.de/Suche/Fotografen/Berlin ，由于某种原因，我无法获得特定元素，而其他元素则可以正常工作。我使用 node.js 和 puppeteer。我需要带有类的元素的 URL，.contains-icon-homepage并且收到针对它的错误消息。如果我以.contains-icon-aktualisieren上面的元素为目标，那么它可以工作。

错误信息：

UnhandledPromiseRejectionWarning：错误：评估失败：TypeError：无法读取 null 的属性“getAttribute”

的HTML：

<article class="mod mod-Treffer" data-teilnehmerid="1057046049">
            <a href="https://www.gelbeseiten.de/gsbiz/64195b36-063f-4401-8536-0d1c71a76326" data-realid="64195b36-063f-4401-8536-0d1c71a76326" data-tnid="1057046049" target="_self"
            >
                
        <div class="mod-hervorhebung">
        
    </div>
        
            <picture class="trefferlisten_logo">
        <source media="(min-width: 768px)" srcset="https://ies.v4all.de/0122/GS/0001/7/5017/30015017_310x190.png" />
        
        <img alt="" data-lazy-src="https://ies.v4all.de/0122/GS/0001/7/5017/30015017_310x190.png"/>
    </picture>
        
        <h2 data-wipe-name="Titel">Rudolph Silke</h2>
        <p class="d-inline-block mod-Treffer--besteBranche">
            Fotografen und Fotostudios
        </p>
        
        <address class="mod mod-AdresseKompakt">
        <p data-wipe-name="Adresse">
            Samariterstr. 33, 
            <span class="nobr">
                10247
                Berlin
            </span>
            (Friedrichshain)
            <span class="mod-AdresseKompakt__entfernung" title="Entfernung ab Suchmittelpunkt">6 km</span>
        </p>

        <p class="mod-AdresseKompakt__phoneNumber" data-hochgestellt-position="end" data-wipe-name="Kontaktdaten">(030) 4 26 66 86</p>

    </address>
                
        <div class="oeffnungszeit_kompakt__zustandsinfo--geschlossen">
            <span>Geschlossen</span>, 
            <span class="nobr">öffnet Samstag um 10:00</span>
        </div>
                
            </a>
                    
                <div class="aktionsleiste_kompakt">
        
        <div class="mod-gsSlider mod-gsSlider--noneOnWhite">
            <span
                    class="mod-gsSlider__arrow mod-gsSlider__arrow--arrow" data-direction="left" data-show="false" data-wipe="{&quot;listener&quot;:&quot;click&quot;,&quot;name&quot;:&quot;Trefferliste: Aktionleiste-button-links&quot;}"></span>
            <span
                    class="mod-gsSlider__arrow mod-gsSlider__arrow--arrow" data-direction="right" data-show="false" data-wipe="{&quot;listener&quot;:&quot;click&quot;,&quot;name&quot;:&quot;Trefferliste: Aktionleiste-button-rechts&quot;}"></span>
            <div class="mod-gsSlider__slider">              
        
            <a
                class="contains-icon-aktualisieren gs-btn"
                rel="noopener"
                href="https://www.gelbeseiten.de/gsbiz/64195b36-063f-4401-8536-0d1c71a76326#aktuelleinformationen"
                data-wipe="{&quot;listener&quot;: &quot;mouseup&quot;, &quot;name&quot;: &quot;Trefferliste Actionbutton Aktualisieren&quot;, &quot;id&quot;: &quot;1057046049&quot;, &quot;synchron&quot;: false}" data-isNeededPromise="false" data-cookieinfo="64195b36-063f-4401-8536-0d1c71a76326=1057046049"
            >Aktualisieren</a>
                            
            <a
                class="contains-icon-homepage gs-btn"
                target="_blank"
                rel=" noopener"
                href="http://www.fotoherz.de"
                data-wipe="{&quot;listener&quot;:&quot;click&quot;, &quot;name&quot;:&quot;Trefferliste Webseite-Button&quot;, &quot;id&quot;:&quot;1057046049&quot;}" data-isNeededPromise="false"
            >Webseite</a>
            
            <a
                class="contains-icon-email gs-btn"
                href="mailto:kontakt@silke-rudolph.de?subject=Anfrage%20%C3%BCber%20Gelbe%20Seiten"
                data-wipe="{&quot;listener&quot;:&quot;click&quot;, &quot;name&quot;:&quot;Trefferliste Email-Button&quot;, &quot;id&quot;:&quot;1057046049&quot;}" data-isNeededPromise="false"
            >E-Mail</a>
            
    
            <span
                class="contains-icon-route_finden gs-btn"
                data-wipe="{&quot;listener&quot;:&quot;click&quot;, &quot;name&quot;:&quot;Trefferliste Navigation-Button&quot;, &quot;id&quot;:&quot;1057046049&quot;}" data-parameters="{&quot;partner&quot;: &quot;googlemaps&quot;, &quot;searchquery&quot;: &quot;Samariterstr%2033%2010247%20Berlin&quot;}" data-target="_blank"
            >Route</span>
    
            <a
                class="contains-icon-details gs-btn"
                rel="noopener"
                href="https://www.gelbeseiten.de/gsbiz/64195b36-063f-4401-8536-0d1c71a76326"
                data-wipe="{&quot;listener&quot;: &quot;mouseup&quot;, &quot;name&quot;: &quot;Trefferliste Actionbutton Mehr Details&quot;, &quot;id&quot;: &quot;1057046049&quot;, &quot;synchron&quot;: false}" data-isNeededPromise="false" data-cookieinfo="64195b36-063f-4401-8536-0d1c71a76326=1057046049"
            >Mehr Details</a>
            
                <div class="mod-gsSlider__spacer"></div>
            </div>
        </div>
    
    </div>
                
        </article>

我的 JS 代码：

const puppeteer = require("puppeteer");

async function getContacts(){
    const browser = await puppeteer.launch({
        headless: false,
        defaultViewport: null
    });

    const page = await browser.newPage();
    const url = "https://www.gelbeseiten.de/Suche/Fotografen/Berlin";

        await page.goto(url);
        await page.waitFor(".mod-Treffer");

        const results = await page.$$eval(".mod-Treffer", rows => {
          return rows.map(row => {
              const properties = {};
              const firma = row.querySelector(".mod-Treffer h2");
              const tel = row.querySelector(".mod-AdresseKompakt__phoneNumber");
              const webSite = row.querySelector(" .contains-icon-homepage");
              properties.firma = firma.innerText;
              properties.tel = tel.innerText;
              properties.webSite = webSite.getAttribute("href");
              return properties;

          })
      })

      console.log(results)
}

getContacts();

标签： javascriptnode.jsweb-scrapingpuppeteer

我已经测试过，有些 .mod-Treffer 元素是空的。因此，当您要查询时.contains-icon-homepage，如果您查询，则不会引发任何错误。尽管如此，当您尝试访问内部标记 attr（即.getAttribute();）时，并且因为对象是null，您会遇到异常。

解决方案：您应该测试非undefined标签。喜欢：

if (webSite !== undefined) {
    properties.webSite = webSite.getAttribute("href");
}

捕获：

javascript - 从 HTML 元素中提取 href 无法使用 node.js

问题描述

解决方案

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