Refs #256 - Implement class-based formats

This allows to extend Tablib with new formats far more easily.

1 files changed, 74 insertions, 16 deletions

diff --git a/src/tablib/formats/__init__.py b/src/tablib/formats/__init__.py
index 12f2610..a462ce0 100644
--- a/src/tablib/formats/__init__.py
+++ b/src/tablib/formats/__init__.py
@@ -1,19 +1,77 @@
 """ Tablib - formats
 """
+from collections import OrderedDict
+from functools import partialmethod
 
-from . import _csv as csv
-from . import _dbf as dbf
-from . import _df as df
-from . import _html as html
-from . import _jira as jira
-from . import _json as json
-from . import _latex as latex
-from . import _ods as ods
-from . import _rst as rst
-from . import _tsv as tsv
-from . import _xls as xls
-from . import _xlsx as xlsx
-from . import _yaml as yaml
-
-# xlsx before as xls (xlrd) can also read xlsx
-available = (json, xlsx, xls, yaml, csv, dbf, tsv, html, jira, latex, ods, df, rst)
+from ._csv import CSVFormat
+from ._dbf import DBFFormat
+from ._df import DataFrameFormat
+from ._html import HTMLFormat
+from ._jira import JIRAFormat
+from ._json import JSONFormat
+from ._latex import LATEXFormat
+from ._ods import ODSFormat
+from ._rst import ReSTFormat
+from ._tsv import TSVFormat
+from ._xls import XLSFormat
+from ._xlsx import XLSXFormat
+from ._yaml import YAMLFormat
+
+
+class Registry:
+    _formats = OrderedDict()
+
+    def register(self, key, format_):
+        from tablib.core import Databook, Dataset
+
+        # Create Databook.<format> read or read/write properties 
+        try:
+            setattr(Databook, format_.title, property(format_.export_book, format_.import_book))
+        except AttributeError:
+            try:
+                setattr(Databook, format_.title, property(format_.export_book))
+            except AttributeError:
+                pass
+
+        # Create Dataset.<format> read or read/write properties,
+        # and Dataset.get_<format>/set_<format> methods.
+        try:
+            try:
+                setattr(Dataset, format_.title, property(format_.export_set, format_.import_set))
+                setattr(Dataset, 'get_%s' % format_.title, partialmethod(Dataset._get_in_format, format_))
+                setattr(Dataset, 'set_%s' % format_.title, partialmethod(Dataset._set_in_format, format_))
+            except AttributeError:
+                setattr(Dataset, format_.title, property(format_.export_set))
+                setattr(Dataset, 'get_%s' % format_.title, partialmethod(Dataset._get_in_format, format_))
+
+        except AttributeError:
+            raise Exception("Your format class should minimally implement the export_set interface.")
+
+        self._formats[key] = format_
+
+    def register_builtins(self):
+        # Registration ordering matters for autodetection.
+        self.register('json', JSONFormat())
+        # xlsx before as xls (xlrd) can also read xlsx
+        self.register('xlsx', XLSXFormat())
+        self.register('xls', XLSFormat())
+        self.register('yaml', YAMLFormat())
+        self.register('csv', CSVFormat())
+        self.register('tsv', TSVFormat())
+        self.register('ods', ODSFormat())
+        self.register('dbf', DBFFormat())
+        self.register('html', HTMLFormat())
+        self.register('jira', JIRAFormat())
+        self.register('latex', LATEXFormat())
+        self.register('df', DataFrameFormat())
+        self.register('rst', ReSTFormat())
+
+    def formats(self):
+        for frm in self._formats.values():
+            yield frm
+
+    def get_format(self, key):
+        return self._formats[key]
+
+
+registry = Registry()