A project in Zend Studio is simply a root folder.
Assuming that the boundaries of the folders subtree delimit internal code is accurate for almost any project at its beginnings, but as time goes by, limitations arise. For example, version and documentation files are not to be considered part of the code of the project.
Zend Studio overcomes those issues by means of the Build Path concept, so that only code that is reachable through the Build Path is internal code. The build Path is then used by Zend Studio for knowing what code to validate. In fact, if you want to exclude some code from the validation check, you have to exclude that code from the Build Path.
Related to the Build Path concept is the Include Path concept. The magic behind “Navigate/ Open Declaration” succeeds for any code that is reachable through the Include Path. If you exclude some code from the Build Path, sooner or later you’ll discover that “Navigate/ Open Declaration” fails for any excluded code. The solution is to add that code as an external source folder.
All of the above makes sense if you consider how Build Path and Include Path are set up. The Build Path is by default anything inside the root folder of the project, and the Include Path is always at least the Build Path. These settings make a standard / simple project work without added configuration. If a project needs fine tuning, then internal code can be defined changing the Build Path, and external code can still be referenced changing the Include Path.
Summary
- the Build Path defines what is the internal code (by default the project subtree)
- the Include Path defines what is the code context (always internal code + external code)
- if you exclude something from the Build Path, chances are that you need to add that something to the Include Path as an external source folder
Example
The build process of Zend Studio finds issues in code from third parties that you host in a library folder of your project. There are so many issues that you can’t easily see your own, and you can’t solve those issues because you want to use third party code “as is”, so that when a new version of that code is available you can simply drop it in place. The solution here is to exclude the library folder from the Build Path and add it to the Include Path as an external source folder.
The above picture shows that the Build Path of a project includes all but the library folder.
The above picture shows that the Include Path of the same project lists the library folder as an external source folder.
—
Zend Studio Documentation: http://files.zend.com/help/Zend-Studio/configuring_build_paths.htm