Catálogo de publicaciones - libros

A dding content to a web site can be quite a chore when you have to format the information yourself. Conversely, making text input look good on a web site requires knowledge of HTML—knowledge most users don’t want to be bothered with. For those of us who are HTML-savvy, it’s still a pain to stop and insert tags into our post during the middle of a brainstorm or literary breakthrough. Paragraph tags, link tags, break tags... yuck. The good news is that Drupal uses prebuilt routines called filters to make data entry easy and efficient. Filters perform text manipulations such as making URLs clickable, converting line breaks to < p> and < br /> tags, and even stripping out malicious HTML. hook_filter() is the mechanism behind filter creation and manipulation of user-submitted data. Filters are almost always a single action such as “strip out all hyperlinks,” “add a random image to this post,” or even “translate this into pirate-speak” (see pirate.module at http://drupal.org/project/pirate).

B oth MySQL and PostgreSQL have built-in full-text search capabilities. While it’s very easy to use these database-specific solutions to build a search engine, you sacrifice control over the mechanics and lose the ability to fine-tune the system according to the behavior of your application. What the database sees as a high-ranking word might actually be considered a “noise” word by the application if it had a say.

D rupal has the ability to upload and download files in a variety of ways. In this chapter you’ll learn about public and private files and how they’re served, deal briefly with the handling of media files, and look at Drupal’s file authentication hook.

T axonomy is the classification of things. Drupal comes with a taxonomy module that allows you to classify nodes (which are, essentially, “things”). In this chapter, you’ll look at the different kinds of taxonomies Drupal supports. You’ll also see how the data is stored, and how to write queries against the taxonomy database tables for incorporation into your own modules. Finally, you’ll see how your modules can be notified of changes to taxonomies, and we’ll go over some common taxonomy-related tasks.

B uilding pages for dynamic web sites requires numerous trips to the database to retrieve information about saved content, site settings, the current user, and so on. Saving the results of these expensive operations for later use is one of the easiest ways within the application layer to speed up a sluggish site. Drupal’s built-in caching API does this automatically for most core data and provides a number of tools for Drupal developers who want to leverage the API for their own purposes.

H TTP is a stateless protocol, which means that each interaction between the web browser and server stands alone. So how do you track a user as he or she navigates through a series of web pages on a web site? You use sessions. Starting with version 4, PHP offers built-in support for sessions via the session family of functions. In this chapter, you’ll see how Drupal uses PHP’s sessions.

J avaScript is ubiquitous. Every mainstream web browser ships with a JavaScript interpreter. Apple’s Dashboard widgets are written with JavaScript. Mozilla Firefox uses JavaScript to implement its user interface. Adobe Photoshop can be scripted with JavaScript. It’s everywhere.

D rupal is developed and used by an international community. Therefore, it supports localization by default. Localization is the replacement of strings in the user interface with translated strings appropriate for the user’s locale. In this chapter, we’ll see how to enable localization and how to selectively replace Drupal’s built-in strings with strings of our own. Then, we’ll look at full-fledged translations and learn how to create, import, and export them.

D rupal “plays well with others.” That is, if there’s an open standard out there, chances are that Drupal supports it either natively or through a contributed module. XML-RPC is no exception. In this chapter, you’ll learn how to take advantage of Drupal’s ability both to send and receive XML-RPC calls.

I t seems that almost daily we see headlines about this or that type of software having a security flaw. Keeping unwanted guests out of your web application and server should be a high priority for any serious developer.