scrapy/scrapy/tests/test_contrib_loader.py

import unittest

from scrapy.contrib.loader import ItemLoader, XPathItemLoader
from scrapy.contrib.loader.processor import Join, Identity, TakeFirst, \
    Compose, MapCompose
from scrapy.item import Item, Field
from scrapy.selector import HtmlXPathSelector
from scrapy.http import HtmlResponse

# test items

class NameItem(Item):
    name = Field()

class TestItem(NameItem):
    url = Field()
    summary = Field()

# test item loaders

class NameItemLoader(ItemLoader):
    default_item_class = TestItem

class TestItemLoader(NameItemLoader):
    name_in = MapCompose(lambda v: v.title())

class DefaultedItemLoader(NameItemLoader):
    default_input_processor = MapCompose(lambda v: v[:-1])

# test processors

def processor_with_args(value, other=None, loader_context=None):
    if 'key' in loader_context:
        return loader_context['key']
    return value

class ItemLoaderTest(unittest.TestCase):

    def test_load_item_using_default_loader(self):
        i = TestItem()
        i['summary'] = u'lala'
        il = ItemLoader(item=i)
        il.add_value('name', u'marta')
        item = il.load_item()
        assert item is i
        self.assertEqual(item['summary'], u'lala')
        self.assertEqual(item['name'], [u'marta'])

    def test_load_item_using_custom_loader(self):
        il = TestItemLoader()
        il.add_value('name', u'marta')
        item = il.load_item()
        self.assertEqual(item['name'], [u'Marta'])

    def test_add_value(self):
        il = TestItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_collected_values('name'), [u'Marta'])
        self.assertEqual(il.get_output_value('name'), [u'Marta'])
        il.add_value('name', u'pepe')
        self.assertEqual(il.get_collected_values('name'), [u'Marta', u'Pepe'])
        self.assertEqual(il.get_output_value('name'), [u'Marta', u'Pepe'])

    def test_replace_value(self):
        il = TestItemLoader()
        il.replace_value('name', u'marta')
        self.assertEqual(il.get_collected_values('name'), [u'Marta'])
        self.assertEqual(il.get_output_value('name'), [u'Marta'])
        il.replace_value('name', u'pepe')
        self.assertEqual(il.get_collected_values('name'), [u'Pepe'])
        self.assertEqual(il.get_output_value('name'), [u'Pepe'])

    def test_iter_on_input_processor_input(self):
        class NameFirstItemLoader(NameItemLoader):
            name_in = TakeFirst()

        il = NameFirstItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_collected_values('name'), [u'marta'])
        il = NameFirstItemLoader()
        il.add_value('name', [u'marta', u'jose'])
        self.assertEqual(il.get_collected_values('name'), [u'marta'])

        il = NameFirstItemLoader()
        il.replace_value('name', u'marta')
        self.assertEqual(il.get_collected_values('name'), [u'marta'])
        il = NameFirstItemLoader()
        il.replace_value('name', [u'marta', u'jose'])
        self.assertEqual(il.get_collected_values('name'), [u'marta'])

        il = NameFirstItemLoader()
        il.add_value('name', u'marta')
        il.add_value('name', [u'jose', u'pedro'])
        self.assertEqual(il.get_collected_values('name'), [u'marta', u'jose'])

    def test_map_compose_filter(self):
        def filter_world(x):
            return None if x == 'world' else x

        proc = MapCompose(filter_world, str.upper)
        self.assertEqual(proc(['hello', 'world', 'this', 'is', 'scrapy']),
                         ['HELLO', 'THIS', 'IS', 'SCRAPY'])

    def test_map_compose_filter_multil(self):
        class TestItemLoader(NameItemLoader):
            name_in = MapCompose(lambda v: v.title(), lambda v: v[:-1])

        il = TestItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'Mart'])
        item = il.load_item()
        self.assertEqual(item['name'], [u'Mart'])

    def test_default_input_processor(self):
        il = DefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'mart'])

    def test_inherited_default_input_processor(self):
        class InheritDefaultedItemLoader(DefaultedItemLoader):
            pass

        il = InheritDefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'mart'])

    def test_input_processor_inheritance(self):
        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(lambda v: v.lower())

        il = ChildItemLoader()
        il.add_value('url', u'HTTP://scrapy.ORG')
        self.assertEqual(il.get_output_value('url'), [u'http://scrapy.org'])
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'Marta'])

        class ChildChildItemLoader(ChildItemLoader):
            url_in = MapCompose(lambda v: v.upper())
            summary_in = MapCompose(lambda v: v)

        il = ChildChildItemLoader()
        il.add_value('url', u'http://scrapy.org')
        self.assertEqual(il.get_output_value('url'), [u'HTTP://SCRAPY.ORG'])
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'Marta'])

    def test_empty_map_compose(self):
        class IdentityDefaultedItemLoader(DefaultedItemLoader):
            name_in = MapCompose()

        il = IdentityDefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'marta'])

    def test_identity_input_processor(self):
        class IdentityDefaultedItemLoader(DefaultedItemLoader):
            name_in = Identity()

        il = IdentityDefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'marta'])

    def test_extend_custom_input_processors(self):
        class ChildItemLoader(TestItemLoader):
            name_in = MapCompose(TestItemLoader.name_in, unicode.swapcase)

        il = ChildItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'mARTA'])

    def test_extend_default_input_processors(self):
        class ChildDefaultedItemLoader(DefaultedItemLoader):
            name_in = MapCompose(DefaultedItemLoader.default_input_processor, unicode.swapcase)

        il = ChildDefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'MART'])

    def test_output_processor_using_function(self):
        il = TestItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), [u'Mar', u'Ta'])

        class TakeFirstItemLoader(TestItemLoader):
            name_out = u" ".join

        il = TakeFirstItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), u'Mar Ta')

    def test_output_processor_using_classes(self):
        il = TestItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), [u'Mar', u'Ta'])

        class TakeFirstItemLoader(TestItemLoader):
            name_out = Join()

        il = TakeFirstItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), u'Mar Ta')

        class TakeFirstItemLoader(TestItemLoader):
            name_out = Join("<br>")

        il = TakeFirstItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), u'Mar<br>Ta')

    def test_default_output_processor(self):
        il = TestItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), [u'Mar', u'Ta'])

        class LalaItemLoader(TestItemLoader):
            default_output_processor = Identity()

        il = LalaItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), [u'Mar', u'Ta'])

    def test_loader_context_on_declaration(self):
        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(processor_with_args, key=u'val')

        il = ChildItemLoader()
        il.add_value('url', u'text')
        self.assertEqual(il.get_output_value('url'), ['val'])
        il.replace_value('url', u'text2')
        self.assertEqual(il.get_output_value('url'), ['val'])

    def test_loader_context_on_instantiation(self):
        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(processor_with_args)

        il = ChildItemLoader(key=u'val')
        il.add_value('url', u'text')
        self.assertEqual(il.get_output_value('url'), ['val'])
        il.replace_value('url', u'text2')
        self.assertEqual(il.get_output_value('url'), ['val'])

    def test_loader_context_on_assign(self):
        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(processor_with_args)

        il = ChildItemLoader()
        il.context['key'] = u'val'
        il.add_value('url', u'text')
        self.assertEqual(il.get_output_value('url'), ['val'])
        il.replace_value('url', u'text2')
        self.assertEqual(il.get_output_value('url'), ['val'])

    def test_item_passed_to_input_processor_functions(self):
        def processor(value, loader_context):
            return loader_context['item']['name']

        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(processor)

        it = TestItem(name='marta')
        il = ChildItemLoader(item=it)
        il.add_value('url', u'text')
        self.assertEqual(il.get_output_value('url'), ['marta'])
        il.replace_value('url', u'text2')
        self.assertEqual(il.get_output_value('url'), ['marta'])

    def test_add_value_on_unknown_field(self):
        il = TestItemLoader()
        self.assertRaises(KeyError, il.add_value, 'wrong_field', [u'lala', u'lolo'])

    def test_compose_processor(self):
        class TestItemLoader(NameItemLoader):
            name_out = Compose(lambda v: v[0], lambda v: v.title(), lambda v: v[:-1])

        il = TestItemLoader()
        il.add_value('name', [u'marta', u'other'])
        self.assertEqual(il.get_output_value('name'), u'Mart')
        item = il.load_item()
        self.assertEqual(item['name'], u'Mart')

class ProcessorsTest(unittest.TestCase):

    def test_take_first(self):
        proc = TakeFirst()
        self.assertEqual(proc([None, '', 'hello', 'world']), 'hello')

    def test_identity(self):
        proc = Identity()
        self.assertEqual(proc([None, '', 'hello', 'world']),
                         [None, '', 'hello', 'world'])

    def test_join(self):
        proc = Join()
        self.assertRaises(TypeError, proc, [None, '', 'hello', 'world'])
        self.assertEqual(proc(['', 'hello', 'world']), u' hello world')
        self.assertEqual(proc(['hello', 'world']), u'hello world')
        self.assert_(isinstance(proc(['hello', 'world']), unicode))

    def test_compose(self):
        proc = Compose(lambda v: v[0], str.upper)
        self.assertEqual(proc(['hello', 'world']), 'HELLO')

    def test_mapcompose(self):
        filter_world = lambda x: None if x == 'world' else x
        proc = MapCompose(filter_world, unicode.upper)
        self.assertEqual(proc([u'hello', u'world', u'this', u'is', u'scrapy']),
                         [u'HELLO', u'THIS', u'IS', u'SCRAPY'])

class TestXPathItemLoader(XPathItemLoader):
    default_item_class = TestItem
    name_in = MapCompose(lambda v: v.title())

class XPathItemLoaderTest(unittest.TestCase):
    response = HtmlResponse(url="", body='<html><body><div id="id">marta</div><p>paragraph</p></body></html>')

    def test_constructor_errors(self):
        self.assertRaises(RuntimeError, XPathItemLoader)

    def test_constructor_with_selector(self):
        sel = HtmlXPathSelector(text=u"<html><body><div>marta</div></body></html>")
        l = TestXPathItemLoader(selector=sel)
        self.assert_(l.selector is sel)
        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])

    def test_constructor_with_response(self):
        l = TestXPathItemLoader(response=self.response)
        self.assert_(l.selector)
        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])

    def test_add_xpath_re(self):
        l = TestXPathItemLoader(response=self.response)
        l.add_xpath('name', '//div/text()', re='ma')
        self.assertEqual(l.get_output_value('name'), [u'Ma'])

    def test_replace_xpath(self):
        l = TestXPathItemLoader(response=self.response)
        self.assert_(l.selector)
        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])
        l.replace_xpath('name', '//p/text()')
        self.assertEqual(l.get_output_value('name'), [u'Paragraph'])

    def test_replace_xpath_re(self):
        l = TestXPathItemLoader(response=self.response)
        self.assert_(l.selector)
        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])
        l.replace_xpath('name', '//div/text()', re='ma')
        self.assertEqual(l.get_output_value('name'), [u'Ma'])


if __name__ == "__main__":
    unittest.main()