Content Inclusion

The heart of LXP's content management is its content inclusion workhorse: the <include> tag. The <include> tag can operate in one of many ways, depending either on the explicit value of the method attribute with which it is initiated, or the implicit context determined by its attributes.

The <include> tag can be used, in its simplest form, to simply include a flat HTML file, such as a standard header, sidebar, and footer. In its more advanced incarnations, the <include> tag can be used to parse token-delimited files by using arbitrary tokens, parse basic XML documents, embed PHP output inline within the LXP document, make direct SQL queries, and, of course, include other LXP documents.

Table 13-1 lists each of the LXP inclusion methods available to the <include> tag. The method in the first column is value that you supply to the <include> tag's method attribute. The alias in the second column describes any alternative names that you can use to invoke the same method. The "Implied by" column shows any attribute values which would imply a method (bypassing the need for an explicit method attribute), and the "Description" column gives a brief description of the method itself.

The source of content inclusion is invariably defined in the src attribute of the <include> tag. In most cases this is a system filename, though it may describe a database source or Apache URI request, depending on the method. When you include a file described by a relative path (one that is not explicitly defined from the root of the filesystem), LXP will use the working directory of the LXP document which is performing the inclusion.