Contents • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Concepts [ ] Document vs. DOM [ ] HTML documents are delivered as 'documents'. These are then, which turns them into the (DOM) internal representation, within the web browser. Presentation by the web browser, such as screen rendering or access by JavaScript, is then performed on this internal model, not the original document. Early HTML documents, and to a lesser extent today, were largely and riddled with. The parsing process was also required to 'fix-up' these errors, as best it could. The resultant model was often not correct (i.e.

It did not represent what a careless coder had originally intended), but it would at least be, according to the HTML standard. A valid model was produced, no matter how bad the ' supplied had been. Only in the rarest cases would the parser abandon parsing altogether. Tags [ ] 'Elements' and 'tags' are terms that are widely confused. HTML documents contain tags, but do not contain the elements. The elements are only generated after the parsing step, from these tags.

An HTML element is an individual component of an HTML document or web page, once this has been parsed into the Document Object Model. HTML is composed of a tree of. Feb 17, 2016. Jeremy Keith & Rachel Andrew HTML5 For Web Designers. A Brief History of Markup (Read this chapter online); The Design of HTML5; Rich Media; Web Forms 2.0; Semantics; Using HTML5 Today. When she's not writing, Rachel often works with other authors as a technical editor.

As is generally understood, the position of an element is indicated as spanning from a start tag, possibly including some child content, and is terminated by an end tag. This is the case for many, but not all, elements within an HTML document. As HTML is based on, its parsing also depends on the use of a, specifically an HTML DTD such as that for HTML 4.01. The DTD specifies which element types are possible (i.e.

It defines the set of element types that go to make up HTML) and it also specifies the valid combinations in which they may appear in a document. It is part of general SGML behavior that where only one valid structure is possible (per the DTD), it is not generally a requirement that the document explicitly states that structure.

As a simple example, the start tag indicating the start of a paragraph element should be closed by a end tag, indicating the end of the element. Also the DTD states that paragraph elements cannot be nested. The HTML document fragment: Para 1 Para 2 Para 3 can thus be inferred to be equivalent to: Para 1 Para 2 Para 3 (If one paragraph element cannot contain another, any currently open paragraph must be closed before starting another.) Because of this implied behavior, based on the combination of the DTD and the individual document, it is not possible to infer elements from the document tags alone, but only by also using an SGML or HTML aware parser, with knowledge of the DTD. Exe To Apk File Converter Free Download For Pc. XML [ ] SGML is complex, which has limited its widespread adoption and understanding. Was developed as a simpler alternative. XML is similar to SGML, that can also use the DTD mechanism to specify the supported elements and their permitted combinations as document structure. XML parsing is simpler.

The relation from tags to elements is always that of parsing the actual tags included in the document, without the implied closures that are part of SGML. In Macros HTML can be formed as XML, either through or through, the parsing of document tags as DOM elements is simplified. Once the DOM of elements is obtained, behaviour beyond that point (i.e. Screen rendering) is identical.%block; vs. Box [ ] Part of this CSS presentation behavior is the notion of the '. This is applied to those elements that CSS considers to be 'block' elements, set through the CSS display: block; declaration. HTML also has a similar concept, although different, and the two are very frequently confused.%block; and%inline; are groups within the HTML DTD that group elements as being either 'block-level' or 'inline'.

Easeus Data Recovery Serial Key Mac there. This is used to define their nesting behavior: block-level elements cannot be placed into an inline context. This behavior cannot be changed, it is fixed in the DTD. Block and inline elements have the appropriate and different CSS behaviors attached to them by default, including the relevance of the box model for particular element types. Note though that this CSS behavior can, and frequently is, changed from the default.