w3c

is -negative margin or padding are invalid CSS aaccording to W3C ? According to Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification - 8.4 Padding properties , negative margin values are valid, negative padding values are not: Unlike margin properties, values for padding values cannot be negative 来源： https://stackoverflow.com/questions/1623163/is-negative-margin-or-padding-invalid-css-according-to-w3c

This question already has an answer here: Why don't self-closing script elements work? 11 answers I've been wondering why none of the revisions to the HTML specification have ever made textarea able to be self-closing. Lot's of SO questions have answered why it is a separate tag from input , and it makes sense to me that they'd want to preserve it as a separate tag for compatibility, but why wouldn't they make <textarea /> just as valid as <textarea></textarea> since this wouldn't break anything as far as I can tell. AmJustSam Because <input /> can't work like container for text, While

In CSS2 Section 9.3: Positioning schemes : An element is called out of flow if it is floated, absolutely positioned, or is the root element. An element is called in-flow if it is not out-of-flow. The flow of an element A is the set consisting of A and all in-flow elements whose nearest out-of-flow ancestor is A. I can understand what out of flow and in-flow means, but I don't understand what "nearest out-of-flow ancestor" in the last sentence means. Can anyone provide a simple example? An element is called out of flow if it is floated, absolutely positioned, or is the root element. If an

I only wrote the following codes in Activator.start() function public void start(BundleContext bundleContext) throws Exception { Activator.context = bundleContext; Node node = new Node() { @Override public Object setUserData(String arg0, Object arg1, UserDataHandler arg2) { // TODO Auto-generated method stub return null; } @Override public void setTextContent(String arg0) throws DOMException { // TODO Auto-generated method stub } @Override public void setPrefix(String arg0) throws DOMException { // TODO Auto-generated method stub } @Override public void setNodeValue(String arg0) throws

I really can't understand this one: it looks like Android has the XMLGregorianCalendar class, because it is documented here . But if you go ahead and try to use it, that's what you get: 10-27 17:21:43.677: E/AndroidRuntime(14850): Caused by: javax.xml.datatype.DatatypeConfigurationException: Provider org.apache.xerces.jaxp.datatype.DatatypeFactoryImpl not found 10-27 17:21:43.677: E/AndroidRuntime(14850): at javax.xml.datatype.DatatypeFactory.newInstance(DatatypeFactory.java:102) This happens on the line: DatatypeFactory datatype = DatatypeFactory.newInstance(); And guess what, it should not

Which is more semantic and valid? <td> <p> content text </p> </td> or <td> content text </td> Leave out the <p> tag unless the content of your table cell is truly a paragraph. It's certainly possible to have paragraphs in tabular data, and in that case a semantic <p> would be appropriately placed. But for the common table with data in the cells eg. numbers, names, etc., don't include the <p> . netrox It depends on your intention. If the cell is going to have just ONE paragraph then it makes no sense to add the <p> tag to it. If you intend to have a few paragraphs in the <td> cell then it makes

We have some kind of problem with a customer which is arguing that there is a semantical difference between two versions of empty tag in an XML file we're sending (pure XML no HTML..). They expect: <our-xml> <some-tag></some-tag> </our-xml> We send: <our-xml> <some-tag /> </our-xml> We are of the opinion that this is exactly the same but we could not really prove the arguments with facts. Only thing we found was in https://www.w3.org/TR/REC-xml/#sec-starttags where it says empty-element tags may be used for any element which has no content. Is there any discussion or more clear paper that we

This question already has an answer here: What does “href” stand for in HTML? 4 answers After writing html for couple of years I realized that I don't really know why the href attribute is named "href" . The HTML Recomendation does not shed light on the subject by saying : This attribute specifies the location of a Web resource, thus defining a link between the current element (the source anchor) and the destination anchor defined by this attribute. Also the HTML 4.01 DTD does not provide a lot of clue . href %URI; #IMPLIED -- URI for linked resource -- I could make an educated guess for the