generalizing build sequence logic

ready for use in first doctype (linuxdoc)

tldp/doctypes/common.py

@@ -34,24 +34,53 @@ class BaseDoctype(object):
         assert None not in (self.source, self.output, self.config)
 
     def generate(self):
-        def last(l): 
-            return l[-1]
-        self.output.prebuild_hook()
-        os.chdir(self.output.dirname)
-        command = list()
-        command.append(self.build_precheck())
-        if not last(command):
-           return False
-        command.append(self.create_htmls())
-        command.append(self.create_pdf())
-        command.append(self.create_txt())
-        command.append(self.create_html())
+        # -- the output directory gets to prepare; must return True
+        #
+        if not self.output.hook_prebuild():
+            return False
 
-        result = all(command)
+        opwd = os.getcwd()
+        os.chdir(self.output.dirname)
+
+        # -- the processor gets to prepare; must return True
+        #
+        if not self.build_precheck():
+            return False
+
+        # -- now, we can walk through build targets, and record a vector
+        #    of success or failure
+        #
+        vector = list()
+
+        def last_command():
+            return vector[-1]
+
+        for target in self.buildorder:
+            premethod = getattr(self, 'pre_' + target, None)
+            mainmethod = getattr(self, target, None)
+            postmethod = getattr(self, 'post_' + target, None)
+            assert mainmethod is not None
+
+            if premethod:
+                vector.append(premethod())
+                if not last_command():
+                    continue
+
+            vector.append(mainmethod())
+            if not last_command():
+                continue
+
+            if postmethod:
+                vector.append(postmethod())
+                if not last_command():
+                    continue
+
+        result = all(vector)
         if result:
-            self.output.build_success_hook()
+            self.output.hook_build_success()
         else:
-            self.output.build_failure_hook()
+            self.output.hook_build_failure()
+        os.chdir(opwd)
         return result
 
 #