I get this structure using the HTMLTreeParser, and I need to have the text contained in the page
doc <- htmlTreeParse(url, useInternalNodes = FALSE)
doc
$file
[1] "http://www.google.com/trends/fetchComponent?q=asdf,qwerty&cid=TIMESERIES_GRAPH_0&export=3"
$version
[1] ""
$children
$children$html
<html>
<body>
<p>// Data table response google.visualization.Query.setResponse([INSERT LOT OF JSON HERE])</p>
</body>
</html>
attr(,"class")
[1] "XMLDocumentContent"
I'm looking for what's on the "p" block. I did not found anything that could help me today.
So, how can I get those data?
If you want to run XPath on the document, you need to set useInternalNodes = TRUE (see the documentation on this argument). The following code should get you started with XPath.
[Note: When I run your code I get an error page, not the document you get.]
library(XML)
url <- "http://www.google.com/trends/fetchComponent?q=asdf,qwerty&cid=TIMESERIES_GRAPH_0&export=3"
doc <- htmlTreeParse(url, useInternalNodes = T)
# XPath examples
p <- doc["//p"] # nodelist of all the <p> elements (there aren't any...)
div <- doc["//div"] # nodelist of all the <div> elememts
scripts <- doc["//script"] # nodelist of all the <script> elements
b.script <- doc["//body/script"] # nodelist of all <script> elements within the <body>
# title of the page
xmlValue(doc["//head/title"][[1]])
# [1] "Google Trends - An error has been detected"
Basically, you can use an XPath string as if it was an index into the document. So in your case,
xmlValue(doc["//p"][[1]])
should return the text contained in the (first) <p> element in doc