On Nov 24, 2008, at 6:46 PM, Asiri Rathnayake wrote:
> Hi Vincent,
>
>
>
>>> + /**
>>> + * OpenOffice server generates redundant paragraphs (with empty
>>> content) to achieve spacing.
>>> + * These paragraphs should be stripped off / replaced with
>>> [EMAIL PROTECTED] <br/>} elements appropriately
>>> + * because otherwise they result in spurious [EMAIL PROTECTED] (%%)}
>>> elements in generated xwiki content.
>>> + *
>>> + * @param document The html document.
>>> + */
>>> + private void filterEmptyParagraphs(Document document)
>>> + {
>>> + NodeList paragraphs = document.getElementsByTagName("p");
>>> + for (int i = 0; i < paragraphs.getLength(); i++) {
>>> + Element paragraph = (Element) paragraphs.item(i);
>>> + if (paragraph.getTextContent().trim().equals("")) {
>>> + // We suspect this is an empty paragraph but it is
>>> possible that it contains other
>>> + // non-textual tags like images. For the moment
>>> we'll only search for internal image
>>> + // tags, we might have to refine this criterion
>>> later.
>>> + NodeList internalImages =
>>> paragraph.getElementsByTagName("img");
>>> + if (internalImages.getLength() == 0) {
>>> +
>>> paragraph.getParentNode().removeChild(paragraph);
>>> + i--;
>>
>> I don't understand this algorithm. There can be a lot of other valid
>> XHTML elements inside a P element (see the XHTML spec). Why are you
>> searching for IMG tags at all? What about all the other tags?
>
>
> Let me explain,
>
> I'm looking for ways to implement a moderate syntax filtering
> mechanism.
> Currently in the strict filtering mode, we strip off most of the
> attributes
> from elements including those of the <p> tag. When we do this, if a
> particular <p> element is empty (if it has no textual content), and
> since
> all of it's attributes were stripped off, the resulting xwiki
> content has no
> (%%) elements.
>
> Example : When <p></p> is converted into xwiki/2.0 the result is
> empty.
Are you sure? Then there's a bug. It should generate 2 empty lines.
> But
> when <p align="justify"></p> is converted into xwiki/2.0 syntax the
> result
> is (% align="justify"%)
Again there should be 2 new lines below the (%...%) text.
> To implement a moderate filtering mechanism, i need to allow the align
> attribute of the <p> tag, because that's required to make the
> content appear
> more pleasing to the user. But when I do this, since openoffice
> server uses
> a lot of <p align="justify"></p> (a.k.a empty paragraph elements) for
> spacing, the resulting wiki content contains a lot of isolated
> (%align="justify"%) elements which doesn't look nice.
ok so you want to remove attributes for empty paragraphs? Then the
method above is badly named and the javadoc not correct since it says
it removes empty paragraphs.
> This is the sole reason why I'm trying to rip off empty paragraph
> elements
> so that i can reduce the number of (%%) in the output.
I'm not sure why you'd want to remove empty paragraphs at all. I
understand removing empty paragraph attributes though. An empty
paragraph has a meaning, it means 2 empty lines. If you remove them
won't you loose those empty lines?
> Now why do i look for <img> tags and not others ?
>
> Well, as you can see in the code, there is a check to see if the <p>
> element
> has any text content in it's sub tree. If there is no such text
> content, we
> can guess that this is one of those empty <p> tags used by
> openoffice server
> for spacing.
Why? For example:
<p><b>hello</b></p>
The text for P is empty.
> But there are situations where <p> tags are used to enclose
> non-textual content like images. So we need to pay special attention
> to
> those cases.
Why images? Why not the other 20 or so HTML elements that can go in
paragraph? (that was my initial question).
> I hope I made myself clear. It's true that it might be too early to
> think
> about a moderate filtering function, but I couldn't resist. The
> thing is,
> the wiki content produced under strict filtering looks very nice,
> but not
> the output of it, It's simply doen't look like the original doc!
>
>
> Again I'm not sure this code is in the right place.
>
>
> Well this might be true. I didn't know if html cleaner can be used
> to strip
> off empty <p> tags or such. Is that possible ?
You are the one who should tell me! :)
BTW I didn't say HTML cleaner. I said HTML cleaner or XHTML parser.
I'm not working on the office importer so I can't answer but you
should be able to answer.
>> For example what
>> will happen if the user provides an empty P as input for a wiki page
>> (using XHTML syntax)? Your code will never run in this case.
>
> I don't understand what you mean by this. Are you refferring to a
> situation
> where the orginal office document contains html content entered by
> the user
> ? Please explain. Because the only input against which this code
> executes is
> the html output generated from office documents. Not user entered
> stuff.
Users can enter content into pages using different syntaxes. One of
them is HTML/XHTML. So as a user, I can enter:
<p></p>
We can't prevent users entering this. So we need to handle it and
ensure it produces what it should produce. As you can see in my use
case there's no office importer code executed but we still need to
handle empty paragraphs.
All this to say I don't understand why you're replacing empty
paragraphs by BRs. I really don't think it's the role of the office
importer to do this, unless I haven't understood what you're trying to
do.
Thanks
-Vincent
>> To be honest I haven't looked at the office importer code for some
>> time but we really need to be careful to move all generic code
>> outside
>> of it and into the HTML cleaner or into the XHTML parser.
>
>
> I agree.
>
> Please let me know what you think about my above comments.
>
> Thanks.
>
> - Asiri
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