Source Code for Module s3.s3codec

  1  # -*- coding: utf-8 -*- 
  2   
  3  """ S3 Encoder/Decoder Base Class 
  4   
  5      @copyright: 2011-2019 (c) Sahana Software Foundation 
  6      @license: MIT 
  7   
  8      Permission is hereby granted, free of charge, to any person 
  9      obtaining a copy of this software and associated documentation 
 10      files (the "Software"), to deal in the Software without 
 11      restriction, including without limitation the rights to use, 
 12      copy, modify, merge, publish, distribute, sublicense, and/or sell 
 13      copies of the Software, and to permit persons to whom the 
 14      Software is furnished to do so, subject to the following 
 15      conditions: 
 16   
 17      The above copyright notice and this permission notice shall be 
 18      included in all copies or substantial portions of the Software. 
 19   
 20      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
 21      EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
 22      OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
 23      NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
 24      HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
 25      WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 26      FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 
 27      OTHER DEALINGS IN THE SOFTWARE. 
 28  """ 
 29   
 30  __all__ = ("S3Codec",) 
 31   
 32  import json 
 33   
 34  from xml.sax.saxutils import escape, unescape 
 35   
 36  from gluon import current 
 37   
 38  from s3utils import s3_str 
 39   
 40  # ============================================================================= 
 41 -class S3Codec(object): 
 42      """ 
 43          Base class for converting S3Resources into/from external 
 44          data formats, for use with S3Importer/S3Exporter 
 45      """ 
 46   
 47      # A list of fields which should be skipped from PDF/XLS exports 
 48      indices = ["id", "pe_id", "site_id", "sit_id", "item_entity_id"] 
 49   
 50      CODECS = {"pdf": "S3RL_PDF", 
 51                "shp": "S3SHP", 
 52                "svg": "S3SVG", 
 53                "xls": "S3XLS", 
 54                "card": "S3PDFCard", 
 55                } 
 56   
 57      # ------------------------------------------------------------------------- 
 58      @classmethod 
 59 -    def get_codec(cls, fmt): 
 60          """ 
 61              Get a codec by representation format 
 62   
 63              @param fmt: the representation format (string) 
 64          """ 
 65   
 66          codec = cls 
 67   
 68          name = cls.CODECS.get(fmt) 
 69          if name: 
 70              package = "applications.%s.modules.s3.codecs.%s" % \ 
 71                        (current.request.application, fmt) 
 72              try: 
 73                  codec = getattr(__import__(package, fromlist=[name]), name) 
 74              except (ImportError, AttributeError): 
 75                  current.log.error("Codec not available: %s" % name) 
 76          else: 
 77              current.log.error("No codec found for '%s' format" % fmt) 
 78   
 79          return codec() 
 80   
 81      # ------------------------------------------------------------------------- 
 82      # API 
 83      #-------------------------------------------------------------------------- 
 84 -    def encode(self, resource, **attr): 
 85          """ 
 86              API Method to encode a resource in the target format, 
 87              to be implemented by the subclass (mandatory) 
 88   
 89              @param resource: the S3Resource 
 90   
 91              @return: a handle to the output 
 92          """ 
 93          raise NotImplementedError 
 94   
 95 -    def decode(self, resource, source, **attr): 
 96          """ 
 97              API Method to decode a source into an S3XML ElementTree, 
 98              to be implemented by the subclass (if the class does decode) 
 99   
100              @param resource: the S3Resource 
101              @param source: the source 
102   
103              @return: an S3XML ElementTree 
104          """ 
105          return current.xml.tree() 
106   
107      # ------------------------------------------------------------------------- 
108      # Utilities 
109      #-------------------------------------------------------------------------- 
110      PY2XML = {"'": "'", '"': """} 
111      @classmethod 
112 -    def xml_encode(cls, s): 
113          """ 
114              XML-escape a string 
115   
116              @param s: the string 
117          """ 
118          if s: 
119              s = escape(s, cls.PY2XML) 
120          return s 
121   
122      #-------------------------------------------------------------------------- 
123      XML2PY = {"'": "'", """: '"'} 
124      @classmethod 
125 -    def xml_decode(cls, s): 
126          """ 
127              XML-unescape a string 
128   
129              @param s: the string 
130          """ 
131          if s: 
132              s = unescape(s, cls.XML2PY) 
133          return s 
134   
135      # ------------------------------------------------------------------------- 
136      @staticmethod 
137 -    def crud_string(tablename, name): 
138          """ 
139              Get a CRUD string 
140   
141              @param tablename: the table name 
142              @param name: the name of the CRUD string 
143          """ 
144   
145          crud_strings = current.response.s3.crud_strings 
146          # CRUD strings for this table 
147          _crud_strings = crud_strings.get(tablename, crud_strings) 
148          return _crud_strings.get(name, 
149                                   # Default fallback 
150                                   crud_strings.get(name, None)) 
151   
152      # ------------------------------------------------------------------------- 
153      # Error handling 
154      # ------------------------------------------------------------------------- 
155      @staticmethod 
156 -    def json_message(success=True, 
157                       statuscode=None, 
158                       message=None, 
159                       **kwargs): 
160          """ 
161              Provide a nicely-formatted JSON Message 
162   
163              @param success: action succeeded or failed 
164              @param status_code: the HTTP status code 
165              @param message: the message text 
166              @param kwargs: other elements for the message 
167   
168              @keyword tree: error tree to include as JSON object (rather 
169                             than as string) for easy decoding 
170          """ 
171   
172          if statuscode is None: 
173              statuscode = success and 200 or 404 
174   
175          status = success and "success" or "failed" 
176          code = str(statuscode) 
177   
178          output = {"status": status, "statuscode": str(code)} 
179   
180          tree = kwargs.get("tree", None) 
181          if message: 
182              output["message"] = s3_str(message) 
183          for k, v in kwargs.items(): 
184              if k != "tree": 
185                  output[k] = v 
186          output = json.dumps(output) 
187          if message and tree: 
188              output = output[:-1] + ', "tree": %s}' % tree 
189          return output 
190   
191  # End ========================================================================= 
192