add api support

Author: michaelliao

www/apis.py

@@ -0,0 +1,72 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+__author__ = 'Michael Liao'
+
+'''
+JSON API definition.
+'''
+
+import re, json, logging, functools
+
+from transwarp.web import ctx
+
+def dumps(obj):
+    return json.dumps(obj)
+
+class APIError(StandardError):
+    '''
+    the base APIError which contains error(required), data(optional) and message(optional).
+    '''
+    def __init__(self, error, data='', message=''):
+        super(APIError, self).__init__(message)
+        self.error = error
+        self.data = data
+        self.message = message
+
+class APIValueError(APIError):
+    '''
+    Indicate the input value has error or invalid. The data specifies the error field of input form.
+    '''
+    def __init__(self, field, message=''):
+        super(APIValueError, self).__init__('value:invalid', field, message)
+
+class APIResourceNotFoundError(APIError):
+    '''
+    Indicate the resource was not found. The data specifies the resource name.
+    '''
+    def __init__(self, field, message=''):
+        super(APIResourceNotFoundError, self).__init__('value:notfound', field, message)
+
+class APIPermissionError(APIError):
+    '''
+    Indicate the api has no permission.
+    '''
+    def __init__(self, message=''):
+        super(APIPermissionError, self).__init__('permission:forbidden', 'permission', message)
+
+def api(func):
+    '''
+    A decorator that makes a function to json api, makes the return value as json.
+
+    @app.route('/api/test')
+    @api
+    def api_test():
+        return dict(result='123', items=[])
+    '''
+    @functools.wraps(func)
+    def _wrapper(*args, **kw):
+        try:
+            r = dumps(func(*args, **kw))
+        except APIError, e:
+            r = json.dumps(dict(error=e.error, data=e.data, message=e.message))
+        except Exception, e:
+            logging.exception(e)
+            r = json.dumps(dict(error='internalerror', data=e.__class__.__name__, message=e.message))
+        ctx.response.content_type = 'application/json'
+        return r
+    return _wrapper
+
+if __name__=='__main__':
+    import doctest
+    doctest.testmod()

www/urls.py

@@ -7,6 +7,8 @@
 
 from transwarp.web import get, post, ctx, view, interceptor, seeother, notfound
 
+from apis import api, APIError, APIValueError, APIPermissionError, APIResourceNotFoundError
+
 from models import User, Blog, Comment
 
 @view('blogs.html')
@@ -15,3 +17,11 @@ def index():
     blogs = Blog.find_all()
     user = User.find_first('where email=?', 'admin@example.com')
     return dict(blogs=blogs, user=user)
+
+@api
+@get('/api/users')
+def api_get_users():
+    users = User.find_by('order by created_at desc')
+    for u in users:
+        u.password = '******'
+    return dict(users=users)