Dynamically generating HTML pages with XMLC (2/4) - exploring XML

Dynamically generating HTML pages with XMLC

The XMLC Development Process

XMLC is designed to support a process where:

1. The graphics designer does the upfront work with the customer, designing a mockup site with static HTML.
2. The initial mockup of the the site is handed off to the programmer (i.e. checked into the source tree), who goes about developing the dynamic presentation logic.
3. The graphics designer continues to refine the look and feel of the site and checks the modified site into the source tree.
4. Both parties can continue to work in parallel, as long as the interface between them, defined by standard id and class attributes in the HTML, remains unchanged, as described below.

Defining Dynamic Components of HTML Pages

Two mechanisms, both part of the HTML 4.0 specification, are used to identify elements (tags) for the creation of dynamic content. The id attribute, valid on most elements, is a document-unique identifier of a particular element. Elements may be grouped using the the class attribute. The class name can then be used to find multiple elements on which to perform an operation. A given element may belong to multiple classes by giving multiple class attributes. While both of these attributes are defined in HTML 4.0, most HTML software ignores attributes that are not understood and their use does not cause problems. Examples of these attributes are:

 <input type="text" name="username" id="username">
    <tr class="deleteRow">

These identifiers serve as the formal interface between the designer of a document and the programmer writing code to generate dynamic content from that page. When the designer and programmer carefully work out these identifiers, both may proceed with full development in parallel.

The use of these id and class attributes does not conflict with other uses, such as access by JavaScript or linking to a Cascading Style Sheet (CSS). All an id does it give that element a unique name, it does not define the usage, the same id can be accessed from JavaScript, CSS, and with XMLC-generated objects. The class attribute is a white-space separated list of names, so it possible for an element to belong to more than one class.

Identifying Elements for Modification

The main reasons for giving elements unique identifiers using the id attribute are:

• Locating text to replace. When the DOM is generated, the resulting text will not be contained directly in an Element object. but in a Text node. To find the text, a containing element is given a unique identifier.
• For modifying structural components of the page. An idcan be attached to a list or table and used to locate it for adding entries or rows.
• For modifying the attributes of specific elements.

When one wants to modify text embedded in a block of text, the HTML 4.0 <span> tag with an id attribute may be used to access a portion of text within a larger text block.

Element Grouping

Some of the useful reasons for grouping multiple elements using the class attribute are:

• Deleting mockup entries in lists or rows in tables to make way for adding the actual data.
• Modifying the attributes of multiple elements, such as changing the color of several, disjoint blocks of text.

Let's compile HTML pages.

Produced by Michael Claßen
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URL: https://www.webreference.com/xml/column23/2.html
Created: Nov 05, 2000
Revised: Nov 05, 2000