2. About
Table
Views
• UI
Component
that
presents
data
in
scrollable
list.
Holds
rows
that
may
divided
into
sec1ons
• Many
purposes
– Navigate
data
– Present
data
– Selectable
list
of
opFons
• Two
styles:
plain
or
grouped
4. Cells
• Table
view
draws
it’s
rows
using
UITableViewCell
objects
– Can
contain
text,
images
or
other
kind
of
content
– Can
contain
background
view
for
normal
and
selected
states
• Framework
defines
four
cell
types,
with
common
informa1on
– Main
label,
detail
label
and
image
– You
can
define
your
own
cell
type
also
5. Responding
to
SelecFons
• As
always,
UITableView
has
an
delegate
• Delegate
methods
are
called
when
user
clicks
a
row.
Method
receives
the
index
of
row
and
secFon
6. EdiFng
Mode
• Table
views
can
support
edi1ng
mode
– User
can
insert
or
delete
rows,
relocate
them
in
the
table
• When
ediFng
a
sequence
of
messages
are
sent
to
data
source
and
delegate
8. Classes
Needed
• Table
View
– UITableView
– Manage
selecFons,
scroll
the
table
view,
insert
or
delete
rows
and
selecFons
– UITableView
inherites
UIScrollView,
defines
scrolling
as
default
• Table
View
Controller
– UITableViewController
– Adds
support
for
many
standard
table
related
behaviors.
Minimize
the
amount
of
code
you
have
to
write.
– Subclass
UITableViewController
• Data
Source
and
Delegate
– UITableView
must
have
delegate
and
data
source:
UITableViewDataSource
and
UITableViewDelegate
9. UITableViewDelegate
• Lot’s
of
opFons:
– Configuring
Rows
for
the
Table
View
– Managing
SelecFons
– Modifying
Header
and
Footer
– EdiFng
Table
Rows
• See
UITableViewDelegate
documentaFon
for
all
methods
10. UITableViewDataSource
• Provides
informaFon
about
the
data
model
of
the
table
view
• Configuring
a
Table
View,
required
methods:
– tableView:cellForRowAtIndexPath:
• Returns
the
UITableViewCell
for
row
– tableView:numberOfRowsInSecFon:
• Returns
the
number
of
rows
11. Xcode
Template
• When
creaFng
a
new
UITableViewController,
let
Xcode
create
a
xib
file
for
you
• Xcode
creates
– Class
that
inherites
UITableViewController
– XIB
with
UITableView
– ConnecFons
• dataSource
-‐>
file
owner
• delegate
-‐>
file
owner
– Template
code
for
dataSource
and
delegate
methods
13. Reusing
UITableViewCells
• If
one
would
have
large
amount
of
UITableViewCells
in
UITableView,
it
would
take
a
lot
of
memory
• Offscreen
cells
are
put
into
a
pool
of
cells
available
for
reuse
• Instead
of
creaFng
a
new
cell
for
every
request,
the
data
source
first
checks
the
pool
– I
need
a
cell
with
this
reuse
iden1fier
(=
name
of
the
cell
class)
• If
unused
cell,
it
configures
it
with
new
data
and
returns
it
to
the
table
view
15. NSIndexPath
• The
NSIndexPath
class
represents
the
path
to
a
specific
node
in
a
tree
of
nested
array
collecFons.
This
path
is
known
as
an
index
path.
• Has
two
properFes:
secFon
and
row
16. NavigaFon
and
Table
View
• Follow
paYerns
that
are
common
to
all
navigaFon-‐based
apps
– Use
data
model
that
has
hierarchical
depth;
arrays,
dicFonary,
some
collecFon
– Array
may
contain
another
array
and
so
on..
• When
user
taps
a
row,
then
– Create
new
table
view
controller,
set
it’s
data
and
push
it
to
navigaFon
controller
20. Editable
Table
View
• User
can
add,
delete
or
move
table
rows
• Set
ediFng
property
to
YES
– [[self tableView]
setEditing:YES];
• And
implement
delegate
methods
for
moving
and
deleFng
