renamed itempipeline.rst to item-pipeline.rst

--HG--
extra : convert_revision : svn%3Ab85faa78-f9eb-468e-a121-7cced6da292c%40626

scrapy/trunk/docs/ref/exceptions.rst

@@ -20,7 +20,7 @@ DropItem
 --------
 
 The exception that must be raised by item pipeline stages to stop processing an
-Item. For more information see :topic:`itempipeline`.
+Item. For more information see :topic:`item-pipeline`.
 
 .. exception:: NotConfigured
 

scrapy/trunk/docs/ref/signals.rst

@@ -141,7 +141,7 @@ Arguments:
  * ``response`` - the response from which the item was scraped
 
 Sent when the engine receives a new scraped item from the spider, and right
-before the item is sent to the :topic:`itempipeline`.
+before the item is sent to the :topic:`item-pipeline`.
 
 .. signal:: item_passed
 
@@ -155,7 +155,7 @@ Arguments:
  * ``pipe_output`` - the output of the item pipeline. Typically, this points to
     the same ``item`` object, unless some pipeline stage created a new item.
 
-Sent after an item has passed al the :topic:`itempipeline` stages without
+Sent after an item has passed al the :topic:`item-pipeline` stages without
 being dropped.
 
 .. signal:: item_dropped
@@ -169,7 +169,7 @@ Arguments:
  * ``response`` - the response from which the item was scraped
  * ``exception`` - the exception that caused the item to be dropped (which must inherit from :exception:`DropItem`) 
 
-Sent after an item has dropped from the :topic:`itempipeline` when some stage
+Sent after an item has dropped from the :topic:`item-pipeline` when some stage
 raised a :exception:`DropItem` exception.
 
 

scrapy/trunk/docs/topics/index.rst

@@ -4,7 +4,7 @@ Topics
 .. toctree::
    :maxdepth: 1
 
-   itempipeline
+   item-pipeline
    downloader-middleware
    selectors
    settings

scrapy/trunk/docs/topics/item-pipeline.rst

@@ -0,0 +1,68 @@
+=============
+Item Pipeline
+=============
+
+After an item has been scraped by a spider it is sent to the Item Pipeline
+which process it through several components that are executed sequentially.
+
+Item pipeline are usually implemented on each project. Typical usage for item
+pipelines are: 
+
+ * HTML cleansing
+ * validation
+ * persistence (storing the scraped item)
+
+
+Writing your own item pipeline
+==============================
+
+Writing your own item pipeline is easy. Each item pipeline component is a
+single Python class that must define the following method:
+
+.. method:: process_item(request, spider)
+
+``request`` is a Request object
+``spider`` is a BaseSpider object
+
+This method is called for every item pipeline component and must either return
+a ScrapedItem (or any descendant class) object or raise a :exception:`DropItem`
+exception. Dropped items are no longer processed by further pipeline
+components.
+
+
+The class can also define the followin optional methods:
+
+.. method:: open_domain(domain)
+
+``domain`` is a string which identifies the spider opened
+
+This method is called when a spider is opened for crawling.
+
+.. method:: close_domain(domain)
+
+``domain`` is a string which identifies the spider closed
+
+This method is called when a spider is closed.
+
+
+Item pipeline example
+=====================
+
+Let's take a look at following hypotetic pipeline that adjusts the ``price``
+attribute for those items that do not include VAT (``price_excludes_vat``
+attribute), and drops those items which don't contain a price::
+
+    from scrapy.core.exceptions import DropItem
+
+    class PricePipeline(object):
+
+        vat_factor = 1.15
+
+        def process_item(self, domain, response, item):
+            if item.price:
+                if item.price_excludes_vat:
+                    item.price = item.price * self.vat_factor
+                return item
+            else:
+                raise DropItem("Missing price in %s" % item)
+

scrapy/trunk/docs/topics/itempipeline.rst

@@ -1,48 +0,0 @@
-=============
-Item Pipeline
-=============
-
-After an item has been scraped by a spider it is sent to the Item Pipeline
-which process it through several stages that are executed sequentially.
-
-Item pipeline are usually implemented on each project. Typical usage for item
-pipelines are: 
-
- * HTML cleansing
- * validation
- * persistence (storing the scraped item)
-
-To implement an item pipeline you need to implement a class which contains a
-``process_item`` method. That method must either return a ScrapedItem (or any
-descendant class) object or raise a :exception:`DropItem` exception. Dropped
-items are no longer processed by further pipeline stages.
-
-Let's take a look at following hypotetic pipeline that adjusts the ``price``
-attribute for those items that do not include VAT (``price_excludes_vat``
-attribute), and drops those items which don't contain a price::
-
-    from scrapy.core.exceptions import DropItem
-
-    class PricePipeline(object):
-
-        vat_factor = 1.15
-
-        def process_item(self, domain, response, item):
-            if item.price:
-                if item.price_excludes_vat:
-                    item.price = item.price * self.vat_factor
-                return item
-            else:
-                raise DropItem("Missing price in %s" % item)
-
-        def open_domain(self, domain):
-            pass
-
-        def close_domains(self, domain):
-            pass
-
-
-You may also noticed the two other methods that a item pipeline class can
-contain: ``open_domain`` which is called when the domain for that spider is
-open, and ``close_domain`` which is called when it's closed.
-