18 Jun
2009
18 Jun
'09
8:01 p.m.
Is there anything like the Xwiki-feed-plugin except that instead of fetching
a feed, it would fetch an HTML document via HTTP, returning a DOM structure
that can be scanned or filtered by API-calls, e.g.:
$fetchedDom = $xwiki.FetchPlugin.getDocumentDOM("http://nielsmayer.com")
$images = $fetchedDom.getImgList()
$media = $fetchedDom.getAnchorHREFsByExtension([".mp3", ".mv4",
".mp4"])
$content = $fetchedDom.getDivListById(['xwikicontent, 'container',
'content'])
Since this would happen on the server, you'd probably need to "fake" being
a
real browser (or just capture the user's browser configuration and pass it
via the call to the hypothetical "getDocumentDOM()" in order to capture an
accurate scraped representation of a modern site.)
The existing examples I've seen store an Xwiki document in the database
first. I was hoping there was an "in memory" option that would allow for the
document to be maintained in the app's context for long enough to process
the remaining stream of plugin calls such as "getDivListById()" or
"getAnchorHREFsByExtension()" and then appropriately dispose the DOM when no
longer referenced, via garbage collection. Maybe compared to the
implementation headaches -- of retrieving a potentially large document into
memory incrementally, parsing it into a DOM incrementally, making that
available in the context, etc -- maybe I should just write the damn document
into the database, scrape it, and delete it.
Since I would use Xwiki to store a JSON "scrape" of the document in the DB
(as a xwiki doc), I could store it in XWiki.JavaScriptExtension[0] of the
retrieved document, and then just delete the wiki-contents after
scraping.... So actually, if anybody has any suggestions for "scraping" with
a retrieved document, stored as Xwiki doc, please, suggest as well! This
seems like an area potentially fraught with peril that many people have
already dealt with, so I would appreciate advice.
Thanks,
Niels
http://nielsmayer.com
18 Jun
18 Jun
9:04 p.m.
New subject: [xwiki-devs] what's the best way to "scrape" an HTML document with Xwiki
Hi Niels,
You could easily call $xwiki.getExternalURL() which returns the
content at a URL.
Then you can use our XHTML parser to generate a XDOM and then do
whatever you want with it.
Only little issue: the renderer is not available in the xwiki content
right now. But if you're doing groovy it should be easy.
For large document we can add a method easily in Parser interface:
parser(Reader, Listener). All you'd need to do is implement Listener a
groovy script for ex and you'd get called for each element in the page.
Thanks
-Vincent
On Jun 18, 2009, at 8:01 PM, Niels Mayer wrote:
Is there anything like the Xwiki-feed-plugin except
that instead of
fetching
a feed, it would fetch an HTML document via HTTP, returning a DOM
structure
that can be scanned or filtered by API-calls, e.g.:
$fetchedDom = $xwiki.FetchPlugin.getDocumentDOM("http://
nielsmayer.com")
$images = $fetchedDom.getImgList()
$media = $fetchedDom.getAnchorHREFsByExtension([".mp3", ".mv4",
".mp4"])
$content = $fetchedDom.getDivListById(['xwikicontent, 'container',
'content'])
Since this would happen on the server, you'd probably need to "fake"
being a
real browser (or just capture the user's browser configuration and
pass it
via the call to the hypothetical "getDocumentDOM()" in order to
capture an
accurate scraped representation of a modern site.)
The existing examples I've seen store an Xwiki document in the
database
first. I was hoping there was an "in memory" option that would allow
for the
document to be maintained in the app's context for long enough to
process
the remaining stream of plugin calls such as "getDivListById()" or
"getAnchorHREFsByExtension()" and then appropriately dispose the DOM
when no
longer referenced, via garbage collection. Maybe compared to the
implementation headaches -- of retrieving a potentially large
document into
memory incrementally, parsing it into a DOM incrementally, making that
available in the context, etc -- maybe I should just write the damn
document
into the database, scrape it, and delete it.
Since I would use Xwiki to store a JSON "scrape" of the document in
the DB
(as a xwiki doc), I could store it in XWiki.JavaScriptExtension[0]
of the
retrieved document, and then just delete the wiki-contents after
scraping.... So actually, if anybody has any suggestions for
"scraping" with
a retrieved document, stored as Xwiki doc, please, suggest as well!
This
seems like an area potentially fraught with peril that many people
have
already dealt with, so I would appreciate advice.
Thanks,
Niels
http://nielsmayer.com
19 Jun
19 Jun
8:50 a.m.
New subject: [xwiki-devs] what's the best way to "scrape" an HTML document with Xwiki
On Thu, Jun 18, 2009 at 9:04 PM, Vincent Massol <vincent(a)massol.net> wrote:
Hi Niels,
You could easily call $xwiki.getExternalURL() which returns the
content at a URL.
Then you can use our XHTML parser to generate a XDOM and then do
whatever you want with it.
Only little issue: the renderer is not available in the xwiki content
right now. But if you're doing groovy it should be easy.
For large document we can add a method easily in Parser interface:
parser(Reader, Listener). All you'd need to do is implement Listener a
groovy script for ex and you'd get called for each element in the page.
Thanks
-Vincent
I agree with Vincent... Groovy is the easiest solution...
In the past, I tried another "weird" solution consisting in integrating a
JavaScript rendering engine on the serverside such as rhino... then
manipulating a DOM in Javascript was quite natural and I could use great
APIs such as prototype... It worked quite well but I'm not sure about the
performance and memory issues but I found this idea funny: Javascript on
serverside... This might seem a bit "heretic" to say that but there are some
products on the market proposing to build websites with javascript on client
and server side...
On Jun 18, 2009, at 8:01 PM, Niels Mayer wrote:
Is there anything like the Xwiki-feed-plugin
except that instead of
fetching
a feed, it would fetch an HTML document via HTTP, returning a DOM
structure
that can be scanned or filtered by API-calls, e.g.:
$fetchedDom = $xwiki.FetchPlugin.getDocumentDOM("http://
nielsmayer.com")
$images = $fetchedDom.getImgList()
$media = $fetchedDom.getAnchorHREFsByExtension([".mp3", ".mv4",
".mp4"])
$content = $fetchedDom.getDivListById(['xwikicontent, 'container',
'content'])
Since this would happen on the server, you'd probably need to "fake"
being a
real browser (or just capture the user's browser configuration and
pass it
via the call to the hypothetical "getDocumentDOM()" in order to
capture an
accurate scraped representation of a modern site.)
The existing examples I've seen store an Xwiki document in the
database
first. I was hoping there was an "in memory" option that would allow
for the
document to be maintained in the app's context for long enough to
process
the remaining stream of plugin calls such as "getDivListById()" or
"getAnchorHREFsByExtension()" and then appropriately dispose the DOM
when no
longer referenced, via garbage collection. Maybe compared to the
implementation headaches -- of retrieving a potentially large
document into
memory incrementally, parsing it into a DOM incrementally, making that
available in the context, etc -- maybe I should just write the damn
document
into the database, scrape it, and delete it.
Since I would use Xwiki to store a JSON "scrape" of the document in
the DB
(as a xwiki doc), I could store it in XWiki.JavaScriptExtension[0]
of the
retrieved document, and then just delete the wiki-contents after
scraping.... So actually, if anybody has any suggestions for
"scraping" with
a retrieved document, stored as Xwiki doc, please, suggest as well!
This
seems like an area potentially fraught with peril that many people
have
already dealt with, so I would appreciate advice.
Thanks,
Niels
http://nielsmayer.com
_______________________________________________
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http://lists.xwiki.org/mailman/listinfo/devs
6 Jul
6 Jul
7:52 a.m.
New subject: [xwiki-devs] what's the best way to "scrape" an HTML document with Xwiki
On Thu, Jun 18, 2009 at 11:50 PM, Pascal Voitot <pascal.voitot.dev(a)gmail.com
wrote:
I agree with Vincent... Groovy is the easiest
solution...
In the past, I tried another "weird" solution consisting in integrating a
JavaScript rendering engine on the serverside such as rhino... then
manipulating a DOM in Javascript was quite natural and I could use great
APIs such as prototype... It worked quite well but I'm not sure about the
performance and memory issues but I found this idea funny: Javascript on
serverside... This might seem a bit "heretic" to say that but there are
some
products on the market proposing to build websites with javascript on
client
and server side...
Belated thanks to Vincent and Pascal for their suggestions regarding "web
scraping." in Xwiki. It turned out jQuery() is the easiest solution for
what I needed, which is quick n' dirty. The suggestions to use groovy are
appreciated: it is an implementation strategy I will need to look into in
the future, I just don't want a tiny sub-project turning into a project in
and of itself, lest I never finish ....
Regarding Pascal's comment about the "heretic" notion of
server-side-javascript: Please note
http://freebaseapps.com/ example app: http://fmdb.freebaseapps.com/
"Introducing Acre: Freebase’s integrated app development and hosting
environment"
This all sounds very familiar, like Xwiki.org/Xwiki.com, combined with a
product version of Exhibit <http://simile-widgets.org/exhibit/>. Which is
exactly what I was alluding to here (
http://www.mail-archive.com/devs@xwiki.org/msg09547.html ) as a very
powerful development&delivery environment, and perhaps signalling a
direction-shift in web-development:
http://freebaseapps.com has lots of similarities to what Xwiki has provided
for years:
- A Browser-based JavaScript IDEincluding syntax highlighting, file
organzation and more
- Open Code for Open Data all Acre files are stored in Freebase and
code sharing is encouraged in a variety of ways
Here's the part that looks exactly like Exhibit -- right down to the syntax
(exhibit uses ex:if=, acre uses acre:if=). In fact, Acre source code, with
their templating language, ends up looking suspiciously close to my
Exhibit+Xwiki (Velocity) code, except they can't access all the rich Java
functionality with their template language like you can in Xwiki.
[image: an Acre script] <http://freebaseapps.com/wiki/index>
Here's where the "heresy" starts. Xwiki uses Java on the server-side.
Freebaseapps uses JavaScript:
- Server-side JavaScriptuse the same language on the server that you
use in the client
This is basically a product version of Exhibit:
- Template Languagea built-in, simple yet powerful XHTML template
language
There's been a good amount of Exhibit/Freebase semantic-web work in the
Simile
project. Again, looks like a productization of MIT semantic web work:
- Built-in support for FreebaseMQL query integration, plus helper
methods included for all Freebase APIs
And finally an application hosting solution. Similar to Xwiki SAS...
Hosted on freebaseapps.comno servers to maintain!
FYI, I found out about this here (also relevant to the topic of
web-scraping in JavaScript)
Freebase Hack Day II: Return of Hack Day
You're invited to attend the Freebase Hack Day and Unconference on July
11th in San Francisco. This event is a great opportunity to learn about what
Freebase is, find out about our developer platform, and chat to Freebase
staff and experts. Some examples of what will be happening on the day:
- We'll be launching Acre 1.0 just a few days before Hack Day. Jason
Douglas will be showing off the features of our hosted app development
platform <http://freebaseapps.com/>, including the ability to share and
clone apps, connect to other APIs with our keystore and OAuth, and build
queries and templated web pages based on Freebase data more easily than ever
before. Acre's come a long way since our last Hack Day, so don't miss this.
(Read more about Acre.<http://blog.freebase.com/category/developer/acre/>)
- The MQL Boot Camp will be run this year by Bryan Culbertson. Learn
how to query against Freebase's structured data about almost 6 million
topics, and see the new features of our query editor, including
tab-completion for syntax and schema. (Read more about
MQL<http://blog.freebase.com/category/developers/mql/>and the query
editor <http://blog.freebase.com/2009/04/22/query-editor-20/>).
- Learn how to use Freebase to enhance your website with structured
data, like the Wall Street
Journal<http://blog.freebase.com/2009/06/25/freebase-data-now-on-wsj-com…m/>,
or build entire apps and websites on Acre, like Tippify<http://tippify.com/>m/>.
- Hack on apps like our Games With A
Purpose<http://blog.freebase.com/tag/gwap/>p/>,
a TV program schedule mashup, and more. If you have a project and you're
looking for partners, technical help, or ideas, bring it with you! We're
also working on having a handful of projects ready for people to hack on who
haven't brought one of their own.)
- Find out about how Freebase's part in the Linked Open
Data<http://linkeddata.org/>world;world, and how to use Semantic
Web <http://blog.freebase.com/category/semantic-web/> techniques and
tools to work with Freebase data.
Niels
http://nielsmayer.com
5647
days inactive
5665
days old
3 comments
3 participants
participants (3)
-
Niels Mayer -
Pascal Voitot -
Vincent Massol