Data Management

Building a simple content management system with Yaapi and PHP

If you're a developer building a content-rich Web site, you've probably looked at several CMS solutions. One interesting option is Yaapi, a PHP class that offers built-in methods to access content stored in a database.

If you're a developer building a content-rich Web site, you've probably looked at several solutions that include (a) a database for your content, (b) a templating system that separates GUI from content, (c) a user-friendly interface to maintain the data in the database, and (d) control over the final appearance of the rendered pages.

One very interesting solution that offers all of the above is Yaapi, an acronym for "Your Article Application Programming Interface." It's a PHP class that offers built-in methods to access content stored in a database. An administration module ships with the class to assist in managing the data, while the API itself is sufficiently sophisticated to perform most common tasks required of a CMS.

Installation

To install and use Yaapi, you'll need a PHP-compliant Web server such as Apache, PHP of course, and a MySQL database server. You can download a copy of Yaapi and uncompress it to a location under your server root.

You also need to create a MySQL database to hold the Yaapi data structures. Use the yaapi.sql file from the source archive to create this database, and then open up the Yaapi configuration in the class constructor (the article.class.php file), and update it with the name and access parameters for the database.

Adding content

To add content to the database, you must use the Yaapi administration module at http://your-server/yaapi-root/admin/ (replace "your-server" with the name of the server where you've installed Yaapi, and replace "yaapi-root" with the path to the directory where you've uncompressed Yaapi). You use this admin module to create (and delete) content categories, and then place articles in those categories. Here's a brief list of the fields you'll encounter during this process:

  • Category: The category for the article
  • Section ID: If you have a two-level hierarchy for your articles, use this parameter to define the second level.
  • Title: The title of the article
  • Author: The article author
  • E-mail: The e-mail address of the article author
  • Approved: A flag indicating if an article has been "approved" for display
  • Image: An optional image URL to be associated with the article
  • Content: The content of the article

A small note in the context of the last item above: Yaapi comes with the ability to break your large article into smaller pages by inserting delimiters in the article text, as exemplified below:

Introduction of article here
#intro#
Page 1 content here
#page#
Page 2 content here
#page#
Page 3 content here
#page#
and so on...

Remember to approve the article after entering it, as only approved articles can be retrieved with the API.

Retrieving categories and lists

Now that you have your content in the database, it's time to use the API to retrieve it and populate a standard HTML template (this template can be altered to match your site design). Listing A contains the base code for the template.

You begin by using Yaapi to retrieve a list of all the articles in a particular category, and displaying their titles, authors, and introductions in the center block. Listing B has the PHP code and Yaapi API calls to accomplish this. That code deserves a bit of explanation.

A necessary first step when using Yaapi is to instantiate an object of the class; this object then exposes API methods and properties to access the content in the database. In order to obtain a list of titles, you use the category ID—this may either be passed on the URL or a default value. The get_titles() method uses this category ID to return an associative array containing article IDs and titles of the (approved) articles present in that category.

Next, the get_article() method drills down further, iterating over the list of article IDs returned in the previous step and returning an object representing each article. The title, author details, and introduction are exposed as properties of this object and can be retrieved using standard object->property notation. Notice that the article title is further object->linked to a separate PHP script, article.php, by the article ID...more on this shortly.


Tip

You can pass the get_article() method an optional second parameter—the page number—to return a specific page of the article.


To finish work on this page, all that's left is to obtain and print a list of available categories (you'll need this for the menu on the left, remember). You accomplish this with the get_categories() method, which returns an associative array containing the names of the categories and their respective IDs. Listing C contains the necessary update to the script from Listing B.

You can see what the end result might look like in Figure A:

Figure A

Output using the get_categories() method

Retrieving article content

The display of the complete article is handled by the article.php script, which is invoked with the article ID. Listing D contains the code for this script, which includes support for page delimiters by allowing you to jump to any page of the article via page number links at the bottom of the page.

The content for each page is retrieved via the get_article() method discussed previously, passing it the article ID and page number. The only significant difference is that the "content" property of the returned object will now store a particular page of the article and not the introduction.

The num_pages() property is used to obtain the total number of pages in the article. This can be combined with a simple for() loop to generate a navigation bar of page numbers and hyperlink each number back to the same script with the same article ID but different page ID.

Figure B shows what the output might look like:

Figure B

Output using the get_article() method

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