apply default configuration to tiles at initialization (closes #100)

now we can get rid of a lot of ugly code

docs/HISTORY.rst

@@ -6,6 +6,9 @@ Because you have to know where your towel is.
 1.0a3 (unreleased)
 ^^^^^^^^^^^^^^^^^^
 
+- Apply default configuration to tiles at initialization (closes `#100`_).
+  [hvelarde]
+
 - Store basic tile data in unicode format to avoid UnicodeDecodeError.
   [hvelarde]
 
@@ -89,6 +92,7 @@ Because you have to know where your towel is.
 
 .. _`PloneFormGen`: https://pypi.python.org/pypi/Products.PloneFormGen
 .. _`#48`: https://github.com/collective/collective.cover/issues/48
+.. _`#100`: https://github.com/collective/collective.cover/issues/100
 .. _`#114`: https://github.com/collective/collective.cover/issues/114
 .. _`#121`: https://github.com/collective/collective.cover/issues/121
 .. _`#123`: https://github.com/collective/collective.cover/issues/123

src/collective/cover/tiles/configuration.py

@@ -1,17 +1,65 @@
+# -*- coding: utf-8 -*-
 
 from persistent.dict import PersistentDict
-
+from plone.namedfile.interfaces import INamedBlobImageField
+from plone.tiles.interfaces import ITileType
 from zope.annotation.interfaces import IAnnotations
-
+from zope.component import getUtility
 from zope.interface import implements
 from zope.interface import Interface
+from zope.schema import getFieldNamesInOrder
+from zope.schema import getFieldsInOrder
+from zope.schema.interfaces import ITextLine
 
 
 ANNOTATIONS_KEY_PREFIX = u'plone.tiles.configuration'
 
 
 class ITilesConfigurationScreen(Interface):
 
+    def _set_default_configuration():
+        """Return a default configuration based on fields defined on the
+        schema; all fields must have, at least, the following attributes:
+
+        visibility: (u'on', u'off')
+            is the field visible? defaults to u'on'
+            XXX: this could be a boolean in the future
+        order: (u'1', u'2', ...)
+            in which order we are going to display the field?
+            XXX: until we fix the UI, we must start with 1 instead of 0
+                 because is most intuitive for end users
+
+        the following attribute is available only in TextLine fields:
+
+        htmltag: (u'h1', u'h2', ...)
+            defaults to u'h2'
+            XXX: this name is a bad one, but I have no proposal for now
+
+        the following attributes are available only in NamedImage fields:
+
+        position: (u'inline', u'left', u'right')
+            defaults to u'left'
+            XXX: this should be named 'alignment' probably
+        imgsize: (any of the available sizes for scaled down images)
+            defaults to u'mini 200:200' or first available size
+            XXX: this should be named 'scale' probably
+
+        final result will be something like this:
+
+        {'date': {'order': u'3', 'visibility': u'on'},
+         'description': {'order': u'1', 'visibility': u'on'},
+         'image': {'imgsize': u'mini 200:200',
+                   'order': u'2',
+                   'position': u'left',
+                   'visibility': u'on'},
+         'subjects': {'order': u'4', 'visibility': u'on'},
+         'title': {'htmltag': u'h2', 'order': u'0', 'visibility': u'on'},
+         'uuid': {'htmltag': u'h2', 'order': u'5', 'visibility': u'on'}}
+
+        obviously some of the fields are not ment to be displayed, but that's
+        another story.
+        """
+
     def get_configuration():
         """
         Get the configuration for a given tile
@@ -40,11 +88,34 @@ def __init__(self, context, request, tile):
         self.request = request
         self.tile = tile
         self.annotations = IAnnotations(self.context)
-        self.key = "%s.%s" % (ANNOTATIONS_KEY_PREFIX, tile.id,)
+        self.key = "%s.%s" % (ANNOTATIONS_KEY_PREFIX, tile.id)
+
+    def _set_default_configuration(self):
+        defaults = {}
+        tile_type = getUtility(ITileType, name=self.tile.__name__)
+        fields = getFieldNamesInOrder(tile_type.schema)
+
+        for name, field in getFieldsInOrder(tile_type.schema):
+            order = unicode(fields.index(name))
+            # default configuration attributes for all fields
+            defaults[name] = {'order': order, 'visibility': u'on'}
+            if ITextLine.providedBy(field):
+                # field is TextLine, we should add 'htmltag'
+                defaults[name]['htmltag'] = u'h2'
+            elif INamedBlobImageField.providedBy(field):
+                # field is an image, we should add 'position' and 'imgsize'
+                defaults[name]['position'] = u'left'
+                defaults[name]['imgsize'] = u'mini 200:200'
+
+        return defaults
 
     def get_configuration(self):
         data = dict(self.annotations.get(self.key, {}))
 
+        if not data:
+            # tile has no configuration; let's apply the default one
+            data = self._set_default_configuration()
+
         return data
 
     def set_configuration(self, configuration):