Changes between Version 8 and Version 9 of PythonPort/Design

Timestamp:

Nov 9, 2007, 11:16:02 AM (18 years ago)

Author:

ghost

Comment:

--

PythonPort/Design

@@ -132 +132 @@
 === Project loading level ===
 
-Porting is in progress yet. Check back later.
+[Note that 'project' is basically a directory where either Jamroot or Jamfile is present].
+Project loading is implemented by the {{{boost.build.build.project}}} module. The {{{ProjectRegistry}}} class maintains all known projects. The {{{Manager.projects()}}} method obtains the project registry for a manager.
+The {{{ProjectRegistry.load}}} method load a project at specific directory. Each project is associated with a Jam module where
+the Jamfile code is execute, with a project target, and a attributes object {{{ProjectAttributes}}} -- which keeps things like project requirements.
+The attributes object is carried over from previous design, and will be eventually merged with the project target.
+
+Loading of project follows these steps:
+ 1. Find Jamfile or Jamroot
+ 2. Prepare default attributes object, where all attribute are inherited from parent. Create new project target.
+ 3. Import all functions that must be useable in Jamfile context to Jam module for the new project
+ 4. Actually load the Jamfile.
+
+If a Jamfile contains call to the 'project' rule, all specified attributes are passed to the {{{ProjectAttributes}}} object, which
+adjust attributes. For example, for requirements, the properties specified in the 'project' rule are merged with the properties inherited from parent.
+
+The list of functions that must be callable from Jamfile is maintained by the {{{ProjectRules}}} class. It has several method that
+are automatically imported in Jamfile, as well as the {{{add_rule}}} method that can be called from anywhere. The {{{add_rule}}}
+method takes a name that must be available in Jamfile, and a callable that will be called. This is the mechanism used to make
+various main target rules available in Jamfile.
+
+The callables imported into Jamfile will be called with exactly parameters passed in Jamfile -- there are no extra parameters implicitly added. While a Jamfile is being loaded, the {{{ProjectRegistry.current}}} method will return project target corresponding to the
+currently loaded Jamfile. Main target rules should use it to decide in which project targets should be defined.
    
 === Metatargets level ===