Using checkouts
===============

Turning a branch into a checkout
--------------------------------

If you have a local branch and wish to make it a checkout, use the
``bind`` command like this::

  bzr bind sftp://centralhost/srv/bzr/PROJECT/trunk

This is necessary, for example, after creating a central branch using
``push`` as illustrated in the previous section.

After this, commits will be applied to the bound branch before
being applied locally.

Turning a checkout into a branch
--------------------------------

If you have a checkout and wish to make it a normal branch, use the
``unbind`` command like this::

  bzr unbind

After this, commits will only be applied locally.

Getting a checkout
------------------

When working in a team using a central branch, one person needs
to provide some initial content as shown in the previous section.
After that, each person should use the ``checkout`` command to
create their local checkout, i.e. the sandbox in which they
will make their changes.

Unlike Subversion and CVS, in Bazaar the ``checkout`` command creates a
local full copy of history in addition to creating a working tree holding
the latest content. This means that operations such as ``diff`` and ``log``
are fast and can still be used when disconnected from the central location.

Getting a lightweight checkout
------------------------------

While Bazaar does its best to efficiently store version history, there
are occasions when the history is simply not wanted. For example, if your
team is managing the content of a web site using Bazaar with a
central repository, then your release process might be as simple as
updating a checkout of the content on the public web server. In this
case, you probably don't want the history downloaded to that location
as doing so:

 * wastes disk space holding history that isn't needed there
 * exposes a Bazaar branch that you may want kept private.

To get a history-less checkout in Bazaar, use the ``--lightweight``
option like this::

  bzr checkout --lightweight sftp://centralhost/srv/bzr/PROJECT/trunk

Of course, many of the benefits of a normal checkout are lost by doing
this but that's a tradeoff you can make if and when it makes sense.

The ``--lightweight`` option only applies to checkouts, not to all branches.

Note: If your code base is really large and disk space on your computer
is limited, lightweight checkouts may be the right choice for you.
Be sure to consider all your options though including
`shared repositories <branching_a_project.html#a-reminder-about-shared-repositories>`_,
`stacked branches <stacked.html>`_, and
`reusing a checkout <reusing_a_checkout.html>`_.

Updating to the latest content
------------------------------

One of the important aspects of working in lockstep with others is
keeping your checkout up to date with the latest changes made to
the central branch. Just as you would in Subversion or CVS, you do
this in Bazaar by using the ``update`` command like this::

  bzr update

This gets any new revisions available in the bound branch and
merges your local changes, if any.

Handling commit failures
------------------------

Note that your checkout *must* be up to date with the bound branch
before running ``commit``. Bazaar is actually stricter about this
than Subversion or CVS - you need to be up to date with the full
tree, not just for the files you've changed. Bazaar will ask you
to run ``update`` if it detects that a revision has been added to
the central location since you last updated.

If the network connection to the bound branch is lost, the commit will
fail. Some alternative ways of working around that are outlined next.