Accessing object in iframe using VBA

2019-01-24 11:19发布

问题:

To the point:

I have successfully used VBA to do the following:

  • Login to a website using getElementsByName

  • Select parameters for the report that will be generated (using getelementsby...)

  • generating the report after selecting parameters which renders the resulting dataset into an iframe on the same page

Important to note - The website is client-side

The above was the simple part, the difficult part is as below:

clicking on a gif image within the iframe that exports the dataset to a csv

I have tried the following:

Dim idoc As HTMLDocument
Dim iframe As HTMLFrameElement
Dim iframe2 As HTMLDocument

Set idoc = objIE.document
Set iframe = idoc.all("iframename")
Set iframe2 = iframe.contentDocument

    Do Until InStr(1, objIE.document.all("iframename").contentDocument.innerHTML, "img.gif", vbTextCompare) = 0
        DoEvents
    Loop

To give some context to the logic above -

  • I accessed the main frame
  • i accessed the iframe by its name element
  • i accessed the content within the iframe
  • I attempted to find the gif image that needs to be clicked to export to csv

It is at this line that it trips up saying "Object doesn't support this property or method"

Also tried accessing the iframe gif by the a element and href attribute but this totally failed. I also tried grabbing the image from its source URL but all this does it take me to the page the image is from.

note: the iframe does not have an ID and strangely the gif image does not have an "onclick" element/event

Final consideration - attempted scraping the iframe using R

accessing the HTML node of the iframe was simple, however trying to access the attributes of the iframe and subsequently the nodes of the table proved unsuccessful. All it returned was "Character(0)"

library(rvest)
library(magrittr)

Blah <-read_html("web address redacted") %>%
  html_nodes("#iframe")%>%
  html_nodes("#img")%>%
  html_attr("#src")%>%
  #read_html()%>%
  head()
Blah

As soon as a i include read_html the following error returns on the script:

Error in if (grepl("<|>", x)) { : argument is of length zero

I suspect this is referring to the Character(0)

Appreciate any guidance here!

Many Thanks,

HTML

<div align="center"> 
    <table id="table1" style="border-collapse: collapse" width="700" cellspacing="0" cellpadding="0" border="0"> 
        <tbody>
            <tr>
                <td colspan="6"> &nbsp;</td>
            </tr> 
            <tr> 
                <td colspan="6"> 
                    <a href="href redacted">
                        <img src="img.gif" width="38" height="38" border="0" align="right">
                    </a>
                    <strong>x - </strong>
                </td>
            </tr> 
        </tbody>
    </table>
</div>

回答1:

It is sometimes tricky with iframes. Based on html you provided I have created this example. Which works locally, but would it work for you as well?

To get to the IFrame the frames collection can be used. Hope you know the name of the IFrame?

Dim iframeDoc As MSHTML.HTMLDocument
Set iframeDoc = doc.frames("iframename").document

Then to go the the image we can use querySelector method e.g. like this:

Dim img As MSHTML.HTMLImg
Set img = iframeDoc.querySelector("div table[id='table1'] tbody tr td a[href^='https://stackoverflow.com'] img")

The selector a[href^='https://stackoverflow.com'] selects anchor which has an href attribute which starts with given text. The ^ denotes the beginning.

Then when we have the image just a simple call to click on its parent which is the desired anchor. HTH


Complete example:

Option Explicit

' Add reference to Microsoft Internet Controls (SHDocVw)
' Add reference to Microsoft HTML Object Library

Sub Demo()

    Dim ie As SHDocVw.InternetExplorer
    Dim doc As MSHTML.HTMLDocument
    Dim url As String

    url = "file:///C:/Users/dusek/Documents/My Web Sites/mainpage.html"
    Set ie = New SHDocVw.InternetExplorer
    ie.Visible = True
    ie.navigate url

    While ie.Busy Or ie.readyState <> READYSTATE_COMPLETE
        DoEvents
    Wend

    Set doc = ie.document

    Dim iframeDoc As MSHTML.HTMLDocument
    Set iframeDoc = doc.frames("iframename").document
    If iframeDoc Is Nothing Then
        MsgBox "IFrame with name 'iframename' was not found."
        ie.Quit
        Exit Sub
    End If

    Dim img As MSHTML.HTMLImg
    Set img = iframeDoc.querySelector("div table[id='table1'] tbody tr td a[href^='https://stackoverflow.com'] img")
    If img Is Nothing Then
        MsgBox "Image element within iframe was not found."
        ie.Quit
        Exit Sub
    Else
        img.parentElement.Click
    End If

    ie.Quit
End Sub

Main page HTML used

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<!-- saved from url=(0016)http://localhost -->
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<title>x -</title>
</head>

<body>
<iframe name="iframename" src="iframe1.html">
</iframe>
</body>

</html>

IFrame HTML used (saved as file iframe1.html)

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<!-- saved from url=(0016)http://localhost -->
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<title>Untitled 2</title>
</head>

<body>
<div align="center"> 
    <table id="table1" style="border-collapse: collapse" width="700" cellspacing="0" cellpadding="0" border="0"> 
        <tbody>
            <tr>
                <td colspan="6"> &nbsp;</td>
            </tr> 
            <tr> 
                <td colspan="6"> 
                    <a href="https://stackoverflow.com/questions/44902558/accessing-object-in-iframe-using-vba">
                        <img src="img.gif" width="38" height="38" border="0" align="right">
                    </a>
                    <strong>x - </strong>
                </td>
            </tr> 
        </tbody>
    </table>
</div>

</body>

</html>