Hi Vincent,
+ /** + * OpenOffice server generates redundant paragraphs (with empty content) to achieve spacing. + * These paragraphs should be stripped off / replaced with {@code <br/>} elements appropriately + * because otherwise they result in spurious {@code (%%)} 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. But when <p align="justify"></p> is converted into xwiki/2.0 syntax the result is (% align="justify"%) 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. 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. 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. 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. 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 ?
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.
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