Tidy defaults.md

Author: stevepiercy

plone.app.dexterity/advanced/defaults.md

@@ -1,23 +1,21 @@
 ---
 myst:
   html_meta:
-    "description": ""
-    "property=og:description": ""
-    "property=og:title": ""
-    "keywords": ""
+    "description": "Content type defaults"
+    "property=og:description": "Content type defaults"
+    "property=og:title": "Content type defaults"
+    "keywords": "Plone, Content type, defaults"
 ---
 
 # Defaults
 
-**Default values for fields on add forms**
+This chapter describes the default values for fields on add forms.
 
-It is often useful to calculate a default value for a field. This value
-will be used on the add form, before the field is set.
+It is often useful to calculate a default value for a field.
+This value will be used on the add form before the field is set.
 
-To continue with our conference example, let’s set the default values
-for the `start` and `end` dates to one week in the future and ten days
-in the future, respectively. We can do this by adding the following to
-`program.py`:
+To continue with our conference example, let's set the default values for the `start` and `end` dates to one week in the future and ten days in the future, respectively.
+We can do this by adding the following to {file}`program.py`.
 
 ```python
 import datetime
@@ -29,8 +27,7 @@ def endDefaultValue():
     return datetime.datetime.today() + datetime.timedelta(10)
 ```
 
-We also need to modify IProgram so the `start` and `end` fields
-use these functions as their `defaultFactory`:
+We also need to modify `IProgram` so the `start` and `end` fields use these functions as their `defaultFactory`.
 
 ```python
 class IProgram(model.Schema):
@@ -48,15 +45,12 @@ class IProgram(model.Schema):
     )
 ```
 
-The `defaultFactory` is a function that will be called when the add form
-is loaded to determine the default value.
+The `defaultFactory` is a function that will be called when the add form is loaded to determine the default value.
 
-The value returned by the method should be a value that’s allowable for
-the field. In the case of `Datetime` fields, that’s a Python `datetime`
-object.
+The value returned by the method should be a value that's allowable for the field.
+In the case of `Datetime` fields, that's a Python `datetime` object.
 
-It is also possible to write a context-aware default factory that will be
-passed the container for which the add form is being displayed:
+It is also possible to write a context-aware default factory that will be passed the container for which the add form is being displayed.
 
 ```python
 from zope.interface import provider
@@ -67,10 +61,7 @@ def getContainerId(context):
     return context.getId()
 ```
 
-It is possible to provide different default values depending on the type
-of context, a request layer, the type of form, or the type of widget
-used. See the [z3c.form] documentation for more details.
+It is possible to provide different default values depending on the type of context, a request layer, the type of form, or the type of widget used.
+See the [z3c.form](https://z3cform.readthedocs.io/en/latest/advanced/validator.html#look-up-value-from-default-adapter) documentation for more details.
 
-We’ll cover creating custom forms later in this manual.
-
-[z3c.form]: https://pypi.python.org/pypi/z3c.form#look-up-value-from-default-adapter
+We'll cover creating custom forms later in this manual.