converted sep 7 for scrapy#629

sep/sep-007.rst

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+=======  =============================
+SEP      7
+Title    ItemLoader processors library
+Author   Ismael Carnales
+Created  2009-08-10
+Status   Draft
+=======  =============================
+
+======================================
+SEP-007: ItemLoader processors library
+======================================
+
+This SEP proposes a library of ``ItemLoader`` processor to ship with Scrapy.
+
+date.py
+=======
+
+``to_date``
+-----------
+
+Converts a date string to a YYYY-MM-DD one suitable for ``DateField``
+
+**Decision**: Obsolete. ``DateField`` doesn't exists anymore.
+
+extraction.py
+=============
+
+``extract``
+-----------
+
+This adaptor tries to extract data from the given locations. Any
+``XPathSelector`` in it will be extracted, and any other data  will be added
+as-is to the result.
+
+**Decision**: Obsolete. Functionality included in ``XpathLoader``.
+
+``ExtractImageLinks``
+
+This adaptor may receive either XPathSelectors pointing to the desired
+locations for finding image urls, or just a list of XPath expressions (which
+will be turned into selectors anyway).
+
+**Decision**: XXX
+
+markup.py
+=========
+
+``remove_tags``
+---------------
+
+Factory that returns an adaptor for removing each tag in the ``tags`` parameter
+found in the given value.  If no ``tags`` are specified, all of them are
+removed.
+
+**Decision**: XXX
+
+``remove_root``
+---------------
+
+This adaptor removes the root tag of the given string/unicode, if it's found.
+
+**Decision**: XXX
+
+``replace_escape``
+------------------
+
+Factory that returns an adaptor for removing/replacing each escape character in
+the ``wich_ones`` parameter found in the given value.
+
+**Decision**: XXX
+
+``unquote``
+-----------
+
+This factory returns an adaptor that receives a string or unicode, removes all
+of the CDATAs and entities (except the ones in CDATAs, and the ones you specify
+in the ``keep`` parameter) and then, returns a new string or unicode.
+
+**Decision**: XXX
+
+misc.py
+=======
+
+``to_unicode``
+--------------
+
+Receives a string and converts it to unicode using the given encoding (if
+specified, else utf-8 is used) and returns a new unicode object. E.g:
+
+::
+
+   >> to_unicode('it costs 20\xe2\x82\xac, or 30\xc2\xa3')
+   [u'it costs 20\u20ac, or 30\xa3']
+
+**Decision**: XXX
+
+``clean_spaces``
+----------------
+
+Converts multispaces into single spaces for the given string. E.g:
+
+::
+
+   >> clean_spaces(u'Hello   sir')
+   u'Hello sir'
+
+**Decision**: XXX
+
+``drop_empty``
+--------------
+
+Removes any index that evaluates to None from the provided iterable. E.g:
+
+::
+
+   >> drop_empty([0, 'this', None, 'is', False, 'an example'])
+   ['this', 'is', 'an example']
+
+**Decision**: Obsolete. Functionality included in reducers.
+
+``delist``
+----------
+
+This factory returns and adaptor that joins an iterable with the specified
+delimiter.
+
+**Decision**: Obsolete. Functionality included in reducers.
+
+``Regex``
+----------
+
+This adaptor must receive either a list of strings or an XPathSelector and
+return a new list with the matches of the given strings with the given regular
+expression (which is passed by a keyword argument, and is mandatory for this
+adaptor).
+
+**Decision**: XXX