Re: mismatch on script tags by getElementsByTagName and XPath

Hi Boris,
thanks for your answer.

On Jul 19, 2:17 pm, Boris Zbarsky <[email protected]> wrote:
> On 7/19/11 8:55 AM, legrass wrote:
>
> > On that page,
> >http://www.dixonvince.com/
>
> > either using Firebug (on Firefox 3.6.17) or XPath I match 31 tags
> > script.
>
> After the page has loaded and the scripts have run, right?

Yes, I run my code it when the browser progress listener triggers page
loaded.

> > However, in my java code (xulrunner 1.9.2), if I retrieve the
> > nsIDOMDocument and getElementsByTagName I get only 20 tags.
>
> How are you retrieving it?


webBrowser.getContentDOMWindow().getDocument().getElementsByTagName(tagname)

where webBrowser is a nsIWebBrowser.

> > Also, if I use the nsIDOMXPathEvaluator to evaluate the //script
> > expression, the result is again 20 nodes.
>
> Using what exact code, on which document?

I've been using this code for a while without problems.
String exp="count(//script)";
Mozilla moz = Mozilla.getInstance();
nsIComponentManager compManager = moz.getComponentManager();
nsIDOMXPathEvaluator xpath = (nsIDOMXPathEvaluator) componentManager
				.createInstanceByContractID(NS_IDOMXPATHEVALUATOR_CONTRACTID,
						null, nsIDOMXPathEvaluator.NS_IDOMXPATHEVALUATOR_IID);
nsIDOMDocument document =
getBrowser().getContentDOMWindow().getDocument();
nsISupports res =
xpath.evaluate(exp,document,xpath.createNSResolver(document),
nsIDOMXPathResult.NUMBER_TYPE,null);

// Obtain the interface corresponding to the XPath XPCOM results
object
nsIDOMXPathResult out = (nsIDOMXPathResult)
res.queryInterface(nsIDOMXPathResult.NS_IDOMXPATHRESULT_IID);
System.out.println(out.getNumberValue());


> > Finally, I tried to save the page with
> > nsIWebBrowserPersist.saveDocument and on within the file there are
> > indeed 20 occurrencies of script.
>
> If you're saving the original html, then chances are some of those
> scripts add other script tags to the DOM.

I though to the saveDocument as I wanted to understand what's going
on. I might be wrong using the code here.
 I'm using the following flags on the nsIWebBrowserPersist object:

persist.setPersistFlags(persist.PERSIST_FLAGS_DONT_CHANGE_FILENAMES|
persist.PERSIST_FLAGS_DONT_FIXUP_LINKS|
persist.PERSIST_FLAGS_NO_BASE_TAG_MODIFICATIONS|
persist.PERSIST_FLAGS_REPLACE_EXISTING_FILES);

long encflags=persist.ENCODE_FLAGS_FORMATTED;
persist.saveDocument(document,localFile,localPath,null,encflags,0);

Thanks for you help.

> -Boris