Update chapter-07.rst

docs/chapter-07.rst

@@ -1236,7 +1236,7 @@ not specify an image.
 Notice that this way multiple records may end to reference the same
 default image file and this could be a problem on a Field having
 ``autodelete`` enabled. When you do not want to allow duplicates for the
-image field (i.e. multiple records referencing the same file) but still
+image field (i.e. multiple records referencing the same file) but still
 want to set a default value for the “upload” then you need a way to copy
 the default file for each new record that does not specify an image.
 This can be obtained using a file-like object referencing the default
@@ -2215,7 +2215,7 @@ In this last expression ``person.thing`` is a shortcut for
 
    db(db.thing.owner_id == person.id)
 
-i.e. the Set of ``thing``\ s referenced by the current ``person``. This
+i.e. the Set of ``thing``\ s referenced by the current ``person``. This
 syntax breaks down if the referencing table has multiple references to
 the referenced table. In this case one needs to be more explicit and use
 a full Query.
@@ -2382,7 +2382,7 @@ An example use which gives much faster selects is:
 
 .. code:: python
 
-   rows = db(query).select(cache=(cache.ram, 3600), cacheable=True)
+   rows = db(query).select(cache=(cache.get, 3600), cacheable=True)
 
 Look at `Caching selects`_, to understand what the trade-offs are.
 
@@ -2764,7 +2764,9 @@ Caching selects
 
 The select method also takes a ``cache`` argument, which defaults to
 None. For caching purposes, it should be set to a tuple where the first
-element is the cache model (``cache.ram``, ``cache.disk``, etc.), and
+element is the cache function with signature `(key, callback, expiration)`
+(ror example ``cache.get`` assuming ``cache``
+is an instance of the py4web cache object), and
 the second element is the expiration time in seconds.
 
 In the following example, you see a controller that caches a select on
@@ -2777,7 +2779,7 @@ the previous data from memory.
 .. code:: python
 
    def cache_db_select():
-       logs = db().select(db.log.ALL, cache=(cache.ram, 60))
+       logs = db().select(db.log.ALL, cache=(cache.get, 60))
        return dict(logs=logs)
 
 The ``select`` method has an optional ``cacheable`` argument, normally
@@ -2800,7 +2802,7 @@ caching:
 
 .. code:: python
 
-   rows = db(query).select(cache=(cache.ram, 3600), cacheable=True)
+   rows = db(query).select(cache=(cache.get, 3600), cacheable=True)
 
 
 Computed and Virtual fields
@@ -2871,7 +2873,7 @@ One can define a ``total_price`` virtual field as
 
    db.item.total_price = Field.Virtual(lambda row: row.item.unit_price * row.item.quantity)
 
-i.e. by simply defining a new field ``total_price`` to be a
+i.e. by simply defining a new field ``total_price`` to be a
 ``Field.Virtual``. The only argument of the constructor is a function
 that takes a row and returns the computed values.
 
@@ -4503,7 +4505,7 @@ The DAL can be used from any Python program simply by doing this:
    from pydal import DAL, Field
    db = DAL('sqlite://storage.sqlite', folder='path/to/app/databases')
 
-i.e. import the DAL, connect and specify the folder which contains the
+i.e. import the DAL, connect and specify the folder which contains the
 .table files (the app/databases folder).
 
 To access the data and its attributes we still have to define all the
@@ -4827,7 +4829,7 @@ globally (not thread safe):
    from pydal.adapters.mysql import SQLAdapter
    SQLAdapter.driver = mysqldb
 
-i.e. ``mysqldb`` has to be *that module* with a .connect() method. You
+i.e. ``mysqldb`` has to be *that module* with a .connect() method. You
 can specify optional driver arguments and adapter arguments:
 
 .. code:: python