scrapy - scrapy-splash如何处理无限滚动？

Question

我想对网页中向下滚动生成的内容进行反向工程。问题出在url https://www.crowdfunder.com/user/following_page/80159?user_id=80159&limit=0&per_page=20&screwrand=933中。 screwrand似乎没有遵循任何模式，因此反转URL无效。我正在考虑使用Splash进行自动渲染。如何使用Splash像浏览器一样滚动？非常感谢!
这是两个请求的代码:

request1 = scrapy_splash.SplashRequest(
    'https://www.crowdfunder.com/user/following/{}'.format(user_id),
     self.parse_follow_relationship,
     args={'wait':2},
     meta={'user_id':user_id, 'action':'following'},
     endpoint='http://192.168.99.100:8050/render.html')

yield request1

request2 = scrapy_splash.SplashRequest(
    'https://www.crowdfunder.com/user/following_user/80159?user_id=80159&limit=0&per_page=20&screwrand=76',
    self.parse_tmp,
    meta={'user_id':user_id, 'action':'following'},
    endpoint='http://192.168.99.100:8050/render.html')

yield request2

ajax request shown in browser console

Answer 1

要滚动页面，您可以编写一个自定义渲染脚本(请参阅http://splash.readthedocs.io/en/stable/scripting-tutorial.html)，如下所示:

function main(splash)
    local num_scrolls = 10
    local scroll_delay = 1.0

    local scroll_to = splash:jsfunc("window.scrollTo")
    local get_body_height = splash:jsfunc(
        "function() {return document.body.scrollHeight;}"
    )
    assert(splash:go(splash.args.url))
    splash:wait(splash.args.wait)

    for _ = 1, num_scrolls do
        scroll_to(0, get_body_height())
        splash:wait(scroll_delay)
    end        
    return splash:html()
end

要渲染此脚本，请使用“执行”终结点而不是render.html终结点:

script = """<Lua script> """
scrapy_splash.SplashRequest(url, self.parse,
                            endpoint='execute', 
                            args={'wait':2, 'lua_source': script}, ...)