Started work on an upgrade script for blueprints

flask/helpers.py

@@ -168,15 +168,18 @@ def url_for(endpoint, **values):
     :param _external: if set to `True`, an absolute URL is generated.
     """
     ctx = _request_ctx_stack.top
+    blueprint_name = request.blueprint
     if not ctx.request._is_old_module:
         if endpoint[:1] == '.':
-            endpoint = request.blueprint + endpoint
+            if blueprint_name is not None:
+                endpoint = blueprint_name + endpoint
+            else:
+                endpoint = endpoint[1:]
     else:
         # TODO: get rid of this deprecated functionality in 1.0
         if '.' not in endpoint:
-            mod = ctx.request.blueprint
-            if mod is not None:
-                endpoint = mod + '.' + endpoint
+            if blueprint_name is not None:
+                endpoint = blueprint_name + '.' + endpoint
         elif endpoint.startswith('.'):
             endpoint = endpoint[1:]
     external = values.pop('_external', False)

scripts/flask-07-upgrade.py

@@ -0,0 +1,171 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+    flask-07-upgrade
+    ~~~~~~~~~~~~~~~~
+
+    This command line script scans a whole application tree and attempts to
+    output an unified diff with all the changes that are necessary to easily
+    upgrade the application to 0.7 and to not yield deprecation warnings.
+
+    This will also attempt to find `after_request` functions that don't modify
+    the response and appear to be better suited for `teardown_request`.
+
+    :copyright: (c) Copyright 2011 by Armin Ronacher.
+    :license: see LICENSE for more details.
+"""
+import re
+import os
+import sys
+import inspect
+import difflib
+import posixpath
+from optparse import OptionParser
+
+try:
+    import ast
+except ImportError:
+    ast = None
+
+
+_string_re_part = r"('([^'\\]*(?:\\.[^'\\]*)*)'" \
+                  r'|"([^"\\]*(?:\\.[^"\\]*)*)")'
+_url_for_re = re.compile(r'\b(url_for\()(%s)' % _string_re_part)
+_after_request_re = re.compile(r'((?:@\S+\.(?:app_)?))(after_request)(\b\s*$)(?m)')
+
+
+def error(message):
+    print >> sys.stderr, 'error:', message
+    sys.exit(1)
+
+
+def make_diff(filename, old, new):
+    for line in difflib.unified_diff(old.splitlines(), new.splitlines(),
+                     posixpath.normpath(posixpath.join('a', filename)),
+                     posixpath.normpath(posixpath.join('b', filename)),
+                     lineterm=''):
+        print line
+
+
+def fix_url_for(contents):
+    def handle_match(match):
+        prefix = match.group(1)
+        endpoint = ast.literal_eval(match.group(2))
+        if endpoint.startswith('.'):
+            endpoint = endpoint[1:]
+        else:
+            endpoint = '.' + endpoint
+        return prefix + repr(endpoint)
+    return _url_for_re.sub(handle_match, contents)
+
+
+def looks_like_teardown_function(node):
+    returns = [x for x in ast.walk(node) if isinstance(x, ast.Return)]
+    if len(returns) != 1:
+        return
+    return_def = returns[0]
+    resp_name = node.args.args[0]
+    if not isinstance(return_def.value, ast.Name) or \
+       return_def.value.id != resp_name.id:
+        return
+
+    for body_node in node.body:
+        for child in ast.walk(body_node):
+            if isinstance(child, ast.Name) and \
+               child.id == resp_name.id:
+                if child is not return_def.value:
+                    return
+
+    return resp_name.id
+
+
+def fix_teardown_funcs(contents):
+
+    def is_return_line(line):
+        args = line.strip().split()
+        return args and args[0] == 'return'
+
+    def fix_single(match, lines, lineno):
+        if not lines[lineno + 1].startswith('def'):
+            return
+        block_lines = inspect.getblock(lines[lineno + 1:])
+        func_code = ''.join(block_lines)
+        if func_code[0].isspace():
+            node = ast.parse('if 1:\n' + func_code).body[0].body
+        else:
+            node = ast.parse(func_code).body[0]
+        response_param_name = looks_like_teardown_function(node)
+        if response_param_name is None:
+            return
+        before = lines[:lineno]
+        decorator = [match.group(1) +
+                     match.group(2).replace('after_', 'teardown_') +
+                     match.group(3)]
+        body = [line.replace(response_param_name, 'exception')
+                for line in block_lines if
+                not is_return_line(line)]
+        after = lines[lineno + len(block_lines) + 1:]
+        return before + decorator + body + after
+
+    content_lines = contents.splitlines(True)
+    while 1:
+        found_one = False
+        for idx, line in enumerate(content_lines):
+            match = _after_request_re.match(line)
+            if match is None:
+                continue
+            new_content_lines = fix_single(match, content_lines, idx)
+            if new_content_lines is not None:
+                content_lines = new_content_lines
+                break
+        else:
+            break
+
+    return ''.join(content_lines)
+
+
+def upgrade_python_file(filename, contents, teardown):
+    new_contents = fix_url_for(contents)
+    if teardown:
+        new_contents = fix_teardown_funcs(contents)
+    make_diff(filename, contents, new_contents)
+
+
+def upgrade_template_file(filename, contents):
+    new_contents = fix_url_for(contents)
+    make_diff(filename, contents, new_contents)
+
+
+def scan_path(path=None, teardown=True):
+    for dirpath, dirnames, filenames in os.walk(path):
+        for filename in filenames:
+            filename = os.path.join(dirpath, filename)
+            with open(filename) as f:
+                contents = f.read()
+            if filename.endswith('.py'):
+                upgrade_python_file(filename, contents, teardown)
+            elif '{% for' or '{% if' or '{{ url_for' in contents:
+                upgrade_template_file(filename, contents)
+
+
+def main():
+    """Entrypoint"""
+    if ast is None:
+        error('Python 2.6 or later is required to run the upgrade script.\n'
+              'The runtime requirements for Flask 0.7 however are still '
+              'Python 2.5.')
+
+    parser = OptionParser()
+    parser.add_option('-T', '--no-teardown-detection', dest='no_teardown',
+                      action='store_true', help='Do not attempt to '
+                      'detect teardown function rewrites.')
+    options, args = parser.parse_args()
+    if not args:
+        args = ['.']
+
+    for path in args:
+        scan_path(path, teardown=not options.no_teardown)
+
+
+if __name__ == '__main__':
+    main()