VBA Selenium FindElementByXPath doesnt find element

问题

I have written a VBA which opens a web link using selenium chrome web driver to scrape of data and I got several problems with which I need your advice on guys.

Code example and outcome 1: On error actived

    Sub test_supplements_store()
    Dim driver As New ChromeDriver
    Dim post As Object

    i = 1

    driver.Get "https://www.thesupplementstore.co.uk/brands/optimum_nutrition?page=4"
On Error Resume Next
    For Each post In driver.FindElementsByClass("desc")
        Cells(i, 1) = post.FindElementByTag("a").Attribute("title")
        Cells(i, 2) = Trim(Split(post.FindElementByClass("size").Text, ":")(1))
        Cells(i, 3) = post.FindElementByXPath(".//span[@class='now']//span[@class='pricetype-purchase-unit multi-price']//span[@class='blu-price blu-price-initialised']").Text
        Cells(i, 4) = post.FindElementByTag("a").Attribute("href")
        i = i + 1
    Next post
End Sub

Code example and outcome 2: On error deactivated

Sub test_supplements_store()
    Dim driver As New ChromeDriver
    Dim post As Object

    i = 1

    driver.Get "https://www.thesupplementstore.co.uk/brands/optimum_nutrition?page=4"
'On Error Resume Next
    For Each post In driver.FindElementsByClass("desc")
        Cells(i, 1) = post.FindElementByTag("a").Attribute("title")
        Cells(i, 2) = Trim(Split(post.FindElementByClass("size").Text, ":")(1))
        Cells(i, 3) = post.FindElementByXPath(".//span[@class='now']//span[@class='pricetype-purchase-unit multi-price']//span[@class='blu-price blu-price-initialised']").Text
        Cells(i, 4) = post.FindElementByTag("a").Attribute("href")
        i = i + 1
    Next post
End Sub

Code example and outcome 3: On error activated

Sub test_supplements_store()
    Dim driver As New ChromeDriver
    Dim post As Object

    i = 1

    driver.Get "https://www.thesupplementstore.co.uk/brands/optimum_nutrition"
On Error Resume Next
    For Each post In driver.FindElementsByClass("desc")
        Cells(i, 1) = post.FindElementByTag("a").Attribute("title")
        Cells(i, 2) = Trim(Split(post.FindElementByClass("size").Text, ":")(1))
        Cells(i, 3) = post.FindElementByXPath(".//span[@class='now']//span[@class='pricetype-purchase-unit multi-price']//span[@class='blu-price blu-price-initialised']").Text
        Cells(i, 4) = post.FindElementByTag("a").Attribute("href")
        i = i + 1
    Next post
End Sub

First example returns all of the 74 items from the website apart from price but in a very long period of time about two minutes.

Second example only returns title into the first cell of the sheet and pops the error out.

Third example returns only 21 but misses to return price of those items that do not have now label. Script runs very quickly, under 10 seconds.

Please advice on how to return all 74 items back together with title, size, price, href.

回答1:

The page you are dealing with has got lay-loading method applied. This is because all items don't load at a time; rather, it loads the rest when you scroll downmost. I used a small javascript function within the code and it solves the issue. I hope this is what the result you were looking for.

Sub test_supplements_store()
    Dim driver As New ChromeDriver
    Dim post As Object

    driver.Get "https://www.thesupplementstore.co.uk/brands/optimum_nutrition"
    On Error Resume Next

    Do While EndofPage = False
        PrevPageHeight = CurrentPageHeight
        CurrentPageHeight = driver.ExecuteScript("window.scrollTo(0, document.body.scrollHeight);var CurrentPageHeight=document.body.scrollHeight;return CurrentPageHeight;")
        driver.Wait 3000
        If PrevPageHeight = CurrentPageHeight Then
            EndofPage = True
        End If
    Loop

    For Each post In driver.FindElementsByXPath("//li[contains(@class,'prod')]")
        i = i + 1: Cells(i, 1) = post.FindElementByXPath(".//a").Attribute("title")
        Cells(i, 2) = Split(post.FindElementByXPath(".//p[@class='size']").Text, ": ")(1)
        Cells(i, 3) = post.FindElementByXPath(".//p[@class='price']//span[@class='now']//span|.//p[@class='price']//span[@class='dynamictype-single']").Text
        Cells(i, 4) = post.FindElementByXPath(".//a").Attribute("href")
    Next post
End Sub

来源：https://stackoverflow.com/questions/45541545/vba-selenium-findelementbyxpath-doesnt-find-element