How to read a field value from a page?

egold2005 · Post by **egold2005** » Tue Aug 25, 2020 8:32 am

Hello,
I used the following code with TWebBrowser to read a page value

function GetElementIdValue(AWebBrowser: TWebBrowser; const ATagName, ATagId, ATagAttrib: string): string;
var vDocument: IHTMLDocument2;
vBody: IHTMLElement2;
vTags: IHTMLElementCollection;
vTag: IHTMLElement;
vIdx: Integer;
begin
result := '';
if not Supports(AWebBrowser.Document, IHTMLDocument2, vDocument) then
exit; //raise Exception.Create('Invalid HTML document');

if not Supports(vDocument.body, IHTMLElement2, vBody) then
exit; //raise Exception.Create('Can''t find <body> element');

vTags := vBody.getElementsByTagName(UpperCase(ATagName));
for vIdx := 0 to Pred(vTags.length) do begin
vTag := vTags.item(vIdx, EmptyParam) as IHTMLElement;
if vTag.id = ATagId then
result := vTag.getAttribute(ATagAttrib, 0)
end
end;

What would be the similar code for Chromium browser?

Thanks a lot.

salvadordf · Post by **salvadordf** » Tue Aug 25, 2020 8:41 am

The DOMVisitor demo shows how to get and set values using :

JavaScript.
The CEF functions to visit the DOM.
The DevTools functions.

The recomemded way is using JavaScript and then send the results back to Delphi using the "console trick", which is also explained in that demo.

egold2005 · Post by **egold2005** » Wed Aug 26, 2020 8:01 am

Thanks Salvador, i got JavaScript method working in my own test application, however this method is async.

Should i use CEF functions for sync mode?

salvadordf · Post by **salvadordf** » Wed Aug 26, 2020 8:08 am

Most of the Chromium features are async, especially if you have to deal with the DOM because it "lives" in a different process.

I would recomend to modify the existing code in your application so it can use async functions.

BriskBard, CEF4Delphi, WebView4Delphi, WebUI4Delphi and WebUI4CSharp

How to read a field value from a page?

How to read a field value from a page?

Re: How to read a field value from a page?

Re: How to read a field value from a page?

Re: How to read a field value from a page?