[Checkins] SVN: zope.file/trunk/src/zope/file/adapters.txt Add tests for adapters module.

[Ulrich Fouquet]

Log message for revision 126564:
  Add tests for adapters module.
  

Changed:
  A   zope.file/trunk/src/zope/file/adapters.txt

-=-
Added: zope.file/trunk/src/zope/file/adapters.txt
===================================================================
--- zope.file/trunk/src/zope/file/adapters.txt	                        (rev 0)
+++ zope.file/trunk/src/zope/file/adapters.txt	2012-06-04 15:30:29 UTC (rev 126564)
@@ -0,0 +1,54 @@
+========
+Adapters
+========
+
+The `zope.file` package provides some adapters to adapt file-like
+objects to `zope.filerepresentation` conform objects. There is a
+read-file adapter and a write-file adapter available. We start with a
+regular `File` object:
+
+   >>> from zope.file.file import File
+   >>> f = File(parameters=dict(charset='utf-8'))
+   >>> f.open('w').write("hello")
+
+Now we can turn this file into a read-only file which we can read and
+whose size we can get:
+
+   >>> from zope.filerepresentation.interfaces import IReadFile, IWriteFile
+   >>> r = IReadFile(f)
+   >>> r.read()
+   'hello'
+
+   >>> r.size()
+   5
+
+Writing to this read-only file is impossible, as the interface does
+not require it:
+
+   >>> r.write("some more content")
+   Traceback (most recent call last):
+   AttributeError: 'ReadFileAdapter' object has no attribute 'write'
+
+With a write-file the opposite happens. We can write but not read:
+
+   >>> w = IWriteFile(f)
+   >>> w.write("some more content")
+   >>> w.read()
+   Traceback (most recent call last):
+   AttributeError: 'WriteFileAdapter' object has no attribute 'read'
+
+The delivered adapters really comply with the promised interfaces:
+
+   >>> from zope.interface.verify import verifyClass, verifyObject
+   >>> from zope.file.adapters import ReadFileAdapter, WriteFileAdapter
+   >>> verifyClass(IReadFile, ReadFileAdapter)
+   True
+
+   >>> verifyObject(IReadFile, r)
+   True
+
+   >>> verifyClass(IWriteFile, WriteFileAdapter)
+   True
+
+   >>> verifyObject(IWriteFile, w)
+   True