Introduction
------------

SyncEvolution synchronizes personal information management (PIM) data
like contacts, calendars, tasks and memos via the SyncML information
synchronization standard. It supports all of these for GNOME's
Evolution and contacts for the system address book of the Nokia
Internet Tablets, Mac OS X and (at one point, but not anymore) the
iPhone. The command-line tool 'syncevolution' (compiled separately for
each of these platforms) executes the synchronization. On platforms
with GTK, the 'sync-ui' provides a graphical user interface. The
project 'Genesis' (available separately) implements a graphical
frontend that sits in the system tray.

The items are exchanged in the vCard 2.1/3.0, iCalender 2.0/vCalendar 1.0
and textual format via the open source Synthesis SyncML engine,
which makes SyncEvolution compatible with the majority of SyncML
servers. Full, one-way and incremental synchronization of items are
supported.

Normally, SyncEvolution does not synchronize with another SyncML
capable device or another computer directly. A SyncML server that that
device and SyncEvolution can talk to is needed. There are several
options for that:
- using a web service like ScheduleWorld or myFUNAMBOL which store
  the data to be synchronized on a server and provide access to it
  via SyncML
- installing a SyncML server like the free one from Funambol on
  one's own server
- installing a SyncML server on the desktop

Since 1.0, SyncEvolution is also capable of synchronizing with another
device via Bluetooth directly. There is also a SyncEvolution HTTP
server which works for single-user scenarios. This is both still a bit
experimental and not explained further here.

The recommended solution is ScheduleWorld because it is easier than
setting up a server and provides better support for vCard and
iCalendar data than the stock Funambol server installation. Setting up
a server on the desktop has the additional problem that not all mobile
devices can communicate with the desktop via HTTP.

All SyncML synchronization modes are supported by SyncEvolution:
- exchanging just the changes between client and server ("two-way")
- sending just the changes in one direction ("one-way-from-client/server")
- replacing all items with the ones stored in the peer
  ("refresh-from-client/server")
- a full synchronization where all items are sent to the server and
  the server then decides which items need to be deleted, added or
  updated on the client ("slow")

The remainder of this document assumes that either Funambol's
myFUNAMBOL service or ScheduleWorld are used: because ScheduleWorld is
based on the Funambol server, configuration and usage are often
similar.

With a server that fully supports SyncML and vCard/iCalender
the following works:
- copy a complete database to the server and restore it
  from the server later
- delete or modify an item locally, then make the same change
  on the server
- delete, modify or add items on the server (by synchronizing with
  another client or using a web interface), then apply the same
  change locally
- conflict resolution (where two clients modify the same item,
  then sync with the server) is handled by the server, but
  SyncEvolution has support which ensures that no data is lost
  by creating duplicates (see "Conflict Resolution" below)

For conflict resolution and synchronization between clients which
support different attributes of items the server needs an
understanding of the format of items. The Funambol server supports
that for contacts, but not yet for the calendar events and tasks that
SyncEvolution sends; see "Configuration with Funambol" below for more
information. ScheduleWorld also works with SyncEvolution for
calendars plus tasks.


Installation
------------

To install SyncEvolution, just unpack an archive with a precompiled
binary for your platform in a directory of your choice or install one
of the packages. Then create a configuration as described below under
"Configuration". No special environment variables are needed, although
one might want to add the directory which contains the "syncevolution"
binary to the shell's PATH variable.

When a binary packages is not available for the target system
and/or is not up-to-date, compiling from source can also be used
to produce a binary. See below in "Compiling from Source" for details.

Although all of the features are covered by unit testing and
have been verified to work, it is highly recommended that you
make a backup of your
   $HOME/.evolution/addressbook
   $HOME/.evolution/calendar
   $HOME/.evolution/tasks
   $HOME/.evolution/memos
directories before running SyncEvolution for the first time with
Evolution. In older Evolution versions the same data is found in
$HOME/evolution.

Configuration templates for SyncML peers are searched in the following
order:
- $SYNCEVOLUTION_TEMPLATE_DIR
- "/usr/share/syncevolution/templates" (prefix may be different,
  depending on compilation)
- built-in templates

The properties defined in a template override the default properties,
so usually only those properties which specifically need to be set for
a certain peer should be listed in its template config. Don't copy
these files, they are not complete! Use the command line or a GUI
instead, which reads the files and produces complete configurations.


Usage
-----

Currently SyncEvolution comes as a simple command line tool which is
configured via files. The general synopsis of the command line
parameters is:

   syncevolution [<options>] [<config>] [<source> ...]

The <config> and the <source> strings are used to find the
configuration files which determine how synchronization is going to
proceed. Each source corresponds to one local address book, calendar,
task list or set of memos and the corresponding database on the
peer. Depending on which parameters are given, different operations
are executed.

Starting with SyncEvolution 1.0, <config> strings can have different
meanings. Typically, a simple string like "scheduleworld" refers to
the configuration for that peer, as it did in previous releases. A
peer is either a SyncML server (the traditional usage of
SyncEvolution) or a client (the new feature in 1.0).

Each peer configuration exists inside a specific context, typically
the "@default" context. All peers in the same context share some parts
of their configuration, for example, which local databases are to be
synchronized.  In that sense, a configuration context can be seen as a
set of local databases plus the peer configurations that are
synchronized against those databases.

When different peers are meant to synchronize different local
databases, then different contexts have to be used when setting up the
peers by appending a context name after the "at" sign, as in
"scheduleworld2@other-context". Later on, if "scheduleworld2" is
unique, the "@other-context" suffix becomes optional.

Sometimes it is also useful to change configuration options of a
context, without modifying a specific peer. This can be done by using
"@default" (or some other context name) without anything before the
"at" sign. The empty string "" is the same as "@default".

   syncevolution

If no arguments are given, then SyncEvolution will list all available
data sources regardless whether there is a configuration file for them
or not. The output includes the identifiers which can then be used to
select those sources in a configuration file. For each source one can
set a different synchronization mode in its configuration file.

   syncevolution <config>

Without the optional list of sources all sources which are enabled in
their configuration file are synchronized.

   syncevolution <config> <source> ...

Otherwise only the ones mentioned on the command line are active. It
is possible to configure sources without activating their
synchronization: if the synchronization mode of a source is set to
"none", the source will be ignored. Explicitly listing such a source
will synchronize it in "two-way" mode once.

Progress and error messages are written into a log file that is
preserved for each synchronization run. Details about that is found in
the "Automatic Backups and Logging" section below. All errors and
warnings are printed directly to the console in addition to writing
them into the log file. Before quitting SyncEvolution will print a
summary of how the local data was modified.  This is done with the
"synccompare" utility script described in the "Exchanging Data"
section.

When the "logdir" option is enabled (since v0.9 done by default for
new configurations), then the same comparison is also done before the
synchronization starts.

In case of a severe error the synchronization run is aborted
prematurely and SyncEvolution will return a non-zero value. Recovery
from failed synchronization is done by forcing a full synchronization
during the next run, i.e. by sending all items and letting the SyncML
server compare against the ones it already knows. This is avoided
whenever possible because matching items during a slow synchronization
can lead to duplicate entries.

After a successful synchronization the server's configuration file is
updated so that the next run can be done incrementally.  If the
configuration file has to be recreated e.g. because it was lost, the
next run recovers from that by doing a full synchronization. The risk
associated with this is that the server might not recognize items that
it already has stored previously which then would lead to duplication
of items.

   syncevolution --configure <options for configuration> <config> [<source> ...]

Options in the configuration can be modified via the command
line. Source properties are changed for all sources unless sources are
listed explicitly.  Some source properties have to be different for
each source, in which case syncevolution must be called multiple times
with one source listed in each invocation.

   syncevolution --remove <config>

Deletes the configuration. If the <config> refers to a specific
peer, only that peer's configuration is removed. If it refers to
a context, that context and all peers inside it are removed.

Note that there is no confirmation question. Neither local data
referenced by the configuration nor the content of log dirs are
deleted.

   syncevolution --run <options for run> <config> [<source> ...]

Options can also be overridden for just the current run, without
changing the configuration. In order to prevent accidentally running a
sync session when a configuration change was intended, either
--configure or --run must be given explicitly if options are specified
on the command line.

   syncevolution --status <config> [<source> ...]

Prints what changes were made locally since the last synchronization.
Depends on access to database dumps from the last run, so using the
"logdir" option is recommended.

   syncevolution --print-servers|--print-configs|--print-peers
   syncevolution --print-config [--quiet] <config> [main|<source> ...]
   syncevolution --print-sessions [--quiet] <config>

These commands print information about existing configurations. When
printing a configuration a short version without comments can be
selected with --quiet. When sources are listed, only their
configuration is shown. "Main" instead or in combination with sources
lists only the main peer configuration.

With --print-session information about previous synchronization
sessions for the selected peer or context are printed. This depends on
the "logdir" option.  The information includes the log directory name
(useful for --restore) and the synchronization report. In combination
with --quiet, only the paths are listed.

   syncevolution --restore <session directory> --before|--after [--dry-run] <config> <source> ...

This restores local data from the backups made before or after a
synchronization session. The --print-sessions command can be used to
find these backups. The source(s) have to be listed explicitly. There
is intentionally no default, because as with --remove there is no
confirmation question. With --dry-run, the restore is only simulated.

The session directory has to be specified explicitly with its path
name (absolute or relative to current directory). It does not have to
be one of the currently active log directories, as long as it contains
the right database dumps for the selected sources.

A restore tries to minimize the number of item changes (see section
"Item Changes and Data Changes"). This means that items that are
identical before and after the change will not be transmitted anew to
the server during the next synchronization. If the server somehow
needs to get a clean copy of all items on the client then, use "--sync
refresh-from-client" in the next run.


Here is a full description of all <options> that can be put in front
of the server name. Whenever an option accepts multiple values, a
question mark can be used to get the corresponding help text and/or
a list of valid values.

--sync|-s <mode>
--sync|-s ?
  Temporarily synchronize the active sources in that mode. Useful
  for a "refresh-from-server" or "refresh-from-client" sync which
  clears all data at one end and copies all items from the other.

--print-servers|--print-configs|--print-peers
  Prints the names of all configured peers to stdout. There is no
  difference between these options, the are just aliases.

--print-config|-p
  Prints the complete configuration for the selected <config>
  to stdout, including up-to-date comments for all properties. The
  format is the normal .ini format with source configurations in
  different sections introduced with [<source>] lines. Can be combined
  with --sync-property and --source-property to modify the configuration
  on-the-fly. When one or more sources are listed after the <config>
  name on the command line, then only the configs of those sources are
  printed. "main" selects the main configuration instead of source
  configurations. Using --quiet suppresses the comments for each property.
  When setting a --template, then the reference configuration for
  that peer is printed instead of an existing configuration.

--configure|-c
  Modify the configuration files for the selected peer. If no such
  configuration exists, then a new one is created using one of the
  template configurations (see --template option). When creating
  a new configuration only the active sources will be set to active
  in the new configuration, i.e. "syncevolution -c scheduleworld addressbook"
  followed by "syncevolution scheduleworld" will only synchronize the
  address book. The other sources are created in a disabled state.
  When modifying an existing configuration and sources are specified,
  then the source properties of only those sources are modified.

--run|-r
  To prevent accidental sync runs when a configuration change was
  intended, but the "--configure" option was not used, "--run" must be
  specified explicitly when sync or source properties are selected
  on the command line and they are meant to be used during a sync
  session triggered by the invocation.

--migrate
  In older SyncEvolution releases a different layout of configuration files
  was used. Using --migrate will automatically migrate to the new
  layout and rename the <config> into <config>.old to prevent accidental use
  of the old configuration. WARNING: old SyncEvolution releases cannot
  use the new configuration!

  The switch can also be used to migrate a configuration in the current
  configuration directory: this preserves all property values, discards
  obsolete properties and sets all comments exactly as if the configuration
  had been created from scratch. WARNING: custom comments in the
  configuration are not preserved.

  --migrate implies --configure and can be combined with modifying
  properties.

--sync-property|-y <property>=<value>
--sync-property|-y ?
--sync-property|-y <property>=?
  Overrides a source-independent configuration property for the
  current synchronization run or permanently when --configure is used
  to update the configuration. Can be used multiple times.  Specifying
  an unused property will trigger an error message.

  When using the configuration layout introduced with 1.0, some of the
  sync properties are shared between peers, for example the directory
  where sessions are logged. Permanently changing such a shared
  property for one peer will automatically update the property for all
  other peers in the same context because the property is stored in a
  shared config file. When printing a config in verbose mode, a summary
  comment shows which properties are shared in which way.

--source-property|-z <property>=<value>
--source-property|-z ?
--source-property|-z <property>=?
  Same as --sync-property, but applies to the configuration of all active
  sources. "--sync <mode>" is a shortcut for "--source-property sync=<mode>".

  When combined with "--configure", the configuration of all sources is
  modified. Properties cannot be specified differently for different
  sources, so if you want to change a source property of just one specific
  sync source, then use "--configure --source-property ... <server> <source>".

  As with sync properties, some properties are shared between peers,
  in particular the selection of which local data to synchronize.

--template|-l <peer name>|default|?<device>
  Can be used to select from one of the built-in default configurations
  for known SyncML peers. Defaults to the <config> name, so --template
  only has to be specified when creating multiple different configurations
  for the same peer, or when using a template that is named differently
  than the peer. "default" is an alias for "scheduleworld" and can be
  used as the starting point for servers which do not have a built-in
  template.

  Each template contains a pseudo-random device ID. Therefore setting the
  "deviceId" sync property is only necessary when manually recreating a
  configuration or when a more descriptive name is desired.

  The available templates for different known SyncML servers are listed when
  using a single question mark instead of template name. When using the
  ?<device> format, a fuzzy search for a template that might be
  suitable for talking to such a device is done. The matching works best
  when using <device> = <Manufacturer>_<Model>. If you don't know the
  manufacturer, you can just keep it as empty. The output in this mode
  gives the template name followed by a short description and a rating how well
  the template matches the device (higher is better).

--status|-t
  The changes made to local data since the last synchronization are
  shown without starting a new one. This can be used to see in advance
  whether the local data needs to be synchronized with the server.

--quiet|-q
  Suppresses most of the normal output during a synchronization. The
  log file still contains all the information.

--keyring|-k
  Save or retrieve passwords from the GNOME keyring when modifying the
  configuration or running a synchronization. Note that using this option
  applies to *all* passwords in a configuration, so setting a single
  password as follows moves the other passwords into the keyring, if
  they were not stored there already:
     --keyring --configure --sync-property proxyPassword=foo

  When passwords were stored in the keyring, their value is set to "-"
  in the configuration. This means that when running a synchronization
  without the --keyring argument, the password has to be entered
  interactively. The --print-config output always shows "-" instead of
  retrieving the password from the keyring.

--help|-h
  Prints usage information.

--version
  Prints the SyncEvolution version.

Use Cases
---------

Migrate a configuration from the  <= 0.7 format to the current one
and/or updates the configuration so that it looks like configurations
created anew with the current syncevolution:
  $ syncevolution --migrate scheduleworld

Deactivate all sources:
  $ syncevolution --configure \
                  --source-property sync=none \
                  scheduleworld

Activate address book synchronization again, using the --sync shortcut:
  $ syncevolution --configure \
                  --sync two-way \
                  scheduleworld addressbook

Change the password for a configuration:
  $ syncevolution --configure \
                  --sync-property password=foo \
                  scheduleworld

Set up another configuration for scheduleworld under a different name:
  $ syncevolution --configure \
                  --sync-property username=joe \
                  --sync-property password=foo \
                  --template scheduleworld \
                  scheduleworld_joe


Configuration
-------------

The configuration file of a certain <peer>@<context> is stored in
   $XDG_CONFIG_HOME/syncevolution/<context>/peers/<peer>/config.ini
with " $HOME/.config" as fallback if XDG_CONFIG_HOME is not
set. The per-peer data source properties are configured in
   $XDG_CONFIG_HOME/syncevolution/<context>/peers/<peer>/sources/<source>/config.ini

The shared properties are in:
   $XDG_CONFIG_HOME/syncevolution/config.ini
   $XDG_CONFIG_HOME/syncevolution/<context>/config.ini
   $XDG_CONFIG_HOME/syncevolution/<context>/sources/

There are also some hidden .synthesis, .internal.ini and
.server.ini directories resp. files. These are used internally
and are not meant to be edited manually.

The configuration of older SyncEvolution releases in the
following directory is also still supported for reading and
updating, but cannot be created anymore from scratch:
   $HOME/.sync4j/evolution/<server>/spds/syncml/config.txt
   $XDG_CONFIG_HOME/syncevolution/<server>/

The format is a simple list of
   <property> = <value>
pairs with one pair per line. Leading spaces and space around the
equals character and at the end of the line are skipped. In other words,
values can neither start or end with spaces nor contain line breaks. Do not
put quotation marks around <value>, they would be treated as part of the
value itself. Lines starting with a hash (#) after optional leading
spaces are treated as comments and skipped.

All supported properties are listed in the template configurations.
Those which have reasonable defaults do not have to be set and are
commented out in the template configurations. Normally at least the
following configuration options need to be adapted:
  <peer>/config.ini
      syncURL
      username
      password
  <peer>/sources/*/config.ini
      uri
      type

See "syncevolution --sync-property ?" for options in the peer
configuration and "syncevolution --source-property ?"
for options in each data source configuration.

Each data source corresponds to one database at the SyncML peer.
The local data source is determined by the type of data given in
"type" and uniquely identified with the "evolutionsource" property.
To get a list of available data sources, run SyncEvolution with no
arguments. "evolutionsource" can be set to either the name or URL
of a data source that SyncEvolution prints then.

The "uri" property is used to identify with which database on the
SyncML server the local data is to be synchronized. Each server
usually documents what needs to be configured here. The template
configurations already have this set correctly.

One can synchronize with multiple server databases in one run, but the
same server database can only be accessed once. To synchronize the
same server database with multiple local data sources, one
has to setup two independent configurations with different "deviceId"
settings and synchronize them separately. To create such a setup simply
copy the whole configuration context, e.g.:
  cp -r ~/.config/syncevolution/localhost ~/.config/syncevolution/localhost_copy
and then edit ~/.config/syncevolution/localhost_copy/config.ini
to update the "deviceId" and the sources/*/config.ini files to update
the "evolutionsource".

If an Evolution data source requires authentication, the
"evolutionuser" and "evolutionpassword" are used as credentials.
In this case the directory that contains the source's config.ini should
only be accessible by the user. Usually these fields can be left
empty. Specifying a single hyphen ("-") as value for a password
instructs SyncEvolution to look for the password in an encrypted
keyring (see --keyring) or to ask for the password at runtime. The
value "${<name of environment variable>}" takes the password from
the named environment variable. Entering the password manually
is the most secure method.

***
*** Warning: setting evolutionuser/password in cases where it is not
*** needed as with local calendars and addressbooks can cause
*** the Evolution backend to hang.
***

SSL encryption of the HTTP connection is supported if the underlying
platform supports it. In order to enable it, use a syncURL with https
instead of http prefix. Not all servers support this, though. In the
default configuration, servers must present a trusted certificate
where the host name of the certificate matches the host name of the
URL. Configuration settings can be used to relax this checking, but
this makes the connection less secure and is not recommended.

If you get errors about a missing certificate file under
/etc/ssl/certs, then check whether the system packages which provide
that file are installed. On Debian/Ubuntu the package is called
"ca-certificates". Alternatively it is possible to specify a different
location of a custom certificate file in the configuration.


Automatic Backups and Logging
-----------------------------

To support recovery from a synchronization which damaged the
local data or modified it in an unexpected way, SyncEvolution
can create the following files during a synchronization:
- a dump of the data in a format which can be imported
  back into Evolution, e.g. .vcf for address books
- a full log file with debug information
- a dump of the data after the synchronization for
  automatic comparison of the before/after state with
  "synccompare"

If the server configuration option "logdir" is set, then
a new directory will be created for each synchronization
in that directory, using the format
  <peer>-<yyyy>-<mm>-<dd>-<hh>-<mm>[-<seq>]
with the various fields filled in with the time when the
synchronization started. The sequence suffix will only be
used when necessary to make the name unique. By default,
SyncEvolution will never delete any data in that log
directory unless explicitly asked to keep only a limited
number of previous log directories.

This is done by setting the "maxlogdirs" limit to something
different than the empty string and 0. If a limit is set,
then SyncEvolution will only keep that many log directories
and start removing the oldest ones when it reaches the limit.
This cleanup is only done after a successful synchronization
and is limited to directories that match the pattern for
SyncEvolution log directory names, so it is safe to put other
files or directories into the configured log directory.

To avoid writing any additional log file or database dumps during
a synchronization the "logdir" can be set to "none". To reduce
the verbosity of the log, set "loglevel". If not set or 0, then
the verbosity is set to 3 = DEBUG when writing to a log file and
2 = INFO when writing to the console directly.


Configuration with ScheduleWorld
--------------------------------

It is recommended to sync against the new vCard 3.0 URI (card3) and
iCalendar 2.0 URIs (cal2, task2), using the "text/vcard", "text/calendar"
and "text/x-todo" type setting respectively. These are the native formats of
Evolution and a lot of effort went into ensuring that they store as
much Evolution data as possible. The "note" URI and "text/x-journal" type
can be used to synchronize memos.

SyncEvolution is primarily tested against ScheduleWorld. The
"scheduleworld" configuration template is ready to be used with these
URIs, one only has to fill in the real username and password.


Configuration with Funambol
---------------------------

A default Funambol installation already contains databases which
SyncEvolution can synchronize with Evolution address books and
calendars. They are adressed in a source config with
  uri = card
for contacts and
  uri = cal
for calendars. Tasks (aka todos) are supported but not shown on
the myFUNAMBOL web site.

At some point the Funambol server started supporting iCalendar 2.0 for
calendars. This is the more capable (and recommended!) format, but the
server does not suggest it as "preferred". Therefore the client's
configuration must use the exclamation qualifier to pick the
2.0 format (part of the current template):
  type = calendar:text/calendar!


Exchanging Data
---------------

SyncEvolution transmits address book entries as vCard 2.1 or 3.0
depending on the type chosen in the configuration. Evolution uses
3.0 internally, so SyncEvolution converts between the two formats
as needed. Calendar items and tasks can be sent and received
in iCalendar 2.0 as well as vCalendar 1.0, but vCalendar 1.0 should
be avoided if possible because it cannot represent all data that
Evolution stores.

How the server stores the items depends on its implementation and
configuration. In the default Funambol server installation, contacts
and calendar items are converted into an internal format, but at
least for contacts it preserves most of the properties used by
Evolution whereas iCalendar 2.0 items are not preserved properly 
in Funambol 6.0. ScheduleWorld uses the same format as Evolution for
calendars and tasks and thus requires no conversion.

To check which data is preserved, one can use this procedure
(described for contacts, but works the same way for calendars and
tasks):
1. synchronize the address book with the server
2. create a new address book in Evolution and view it in Evolution
   once (the second step is necessary in at least Evolution 2.0.4
   to make the new address book usable in SyncEvolution)
3. add a configuration for that second address book and the
   same URI on the SyncML server
4. synchronize again, this time using the other data source

Now one can either compare the address books in Evolution or do that
automatically, described here for contacts:
- save the complete address books: mark all entries, save as vCard
- invoke synccompare with two file names as arguments and it will
  normalize and compare them automatically

Normalizing is necessary because the order of cards and their
properties as well as other minor formatting aspects may be
different. The output comes from a side-by-side comparison, but
is augmented by the script so that the context of each change
is always the complete item that was modified. Lines or items
following a ">" on the right side were added, those on the
left side followed by a "<" were removed, and those with
a "|" between text on the left and right side were modified.

The automatic unit testing (see HACKING) contains a "testItems"
test which verifies the copying of special entries using the
same method.

Modifying one of the address books or even both at the same time and
then synchronizing back and forth can be used to verify that
SyncEvolution works as expected. If you do not trust SyncEvolution or
the server, then it is prudent to run these checks with a copy of the
original address book. Make a backup of the .evolution/addressbook
directory.


Item Changes and Data Changes
-----------------------------

SyncML clients and servers consider each entry in a database as one
item. Items can be added, removed or updated. This is the item change
information that client and server exchange during a normal,
incremental synchronization.

If an item is saved, removed locally, and reimported, then this is
usually reported to a peer as "one item removed, one added" because
the information available to SyncEvolution is not sufficient to
determine that this is in fact the same item. One exception are
iCalendar 2.0 items with their globally unique ID: the modification
above will be reported to the server as "one item updated".

That is better, but still not quite correct because the content of the
item has not changed, only the meta information about it which is used
to detect changes. This cannot be avoided without creating additional
overhead for normal synchronizations.

SyncEvolution reports "item changes" (the number of added, removed and
updated items) as well as data changes. These data changes are
calculated by comparing database dumps. Because this data comparison
ignores information about which data belongs to which item, it is able
to detect that re-adding an item that was removed earlier does not
change the data, in contrast to the item changes. On the other hand,
removing one item and adding a different one may look like updating
just one item, which is not quite correct.


Conflict Resolution
-------------------

If two clients make changes to the same item, the first one to
synchronize will copy its changes to the server. The second one
then runs into a conflict when it tries to push its own changes
into the server.

The SyncML server now has to decide how to proceed. Some decide
to preserve both conflicting items, leading to duplicates which
have to be merged manually later. Other servers merge automatically
and throw away conflicting data based on heuristics; this may
remove valid data. The client has no control over the method
chosen by the server.

Merging items on the server is difficult because the SyncML protocol
does not specify which parts of a conflicting item were updated.
In general a server can only make more or less educated guesses
which might lead to data loss. It is better to avoid this situation
in the first place by synchronizing before making changes.


Known Problems + Support
------------------------

Please visit http://syncevolution.org/ for up-to-date
information about known problems and links to places where further
help can be found.


Compiling from Source
---------------------

To compile the code the source or an installation of the Synthesis
SyncML engine is needed. A compatible snapshot of it is included in
SyncEvolution source packages and will be used
automatically. Instructions for working with upstream Synthesis
sources directly are contained in the HACKING document.

Also needed are the Evolution and Boost (>= 1.35) development
files. For HTTP, either Curl or libsoup can be used.

On Debian based systems the required packages can be installed with
   apt-get install evolution-data-server-dev \
                   libecal1.2-dev libebook1.2-dev \
                   libsoup2.4-dev \
                   libboost-dev

libboost-dev >= 1.34, available as libboost1.35-dev backport for Debian Etch.

Necessary on some distros due to bad dependencies (not needed by SyncEvolution itself):
   apt-get install libdb3-dev

Optional (enables reading proxy settings from GNOME preferences):
   apt-get install libsoup-gnome2.4-dev

Optional (enables direct sync with phones):
   apt-get install libopenobex-dev libbluetooth-dev

Optional (only used for SHA-256 when glib is not already a dependency):
   apt-get install libnss3-dev

For compiling libsynthesis:
   apt-get install libpcre3-dev libsqlite3-dev libexpat-dev libz-dev

This was copied from the libsynthesis README.

The test framework also requires CPPUnit:
   apt-get install libcppunit-dev

For the GUI and its D-Bus based service backend:
   apt-get install libdbus-glib-1-dev \
                   xsltproc \
                   libglib2.0-dev \
                   libgtk2.0-dev libglade2-dev \
                   libgnome-keyring-dev \
                   libgconf2-dev libgnomevfs2-dev

Optional packages for GUI:
   apt-get install libunique-dev

libunique = ensure that GTK GUI only runs once per user

Optional packages for GNOME Bluetooth Panel plugin:
   apt-get install libgnome-bluetooth-dev

The plugin adds a button to invoke sync-UI after a device
was paired which supports SyncML.

The build system is the normal autotools system. See INSTALL for
general instructions how to use that and "./configure --help" for
SyncEvolution specific options.

Note that compiling without the Evolution development files is
possible. But because this is usually not what people want,
the configure script needs explicit --disable-ecal --disable-ebook
parameters, otherwise it will refuse to compile without Evolution
support.

When compiling from a git checkout, remember to run "./autogen.sh".
It depends on:
  apt-get install libtool intltool automake


Supporting SyncEvolution
------------------------

SyncEvolution is free software: available free of charge and you have
the freedom of modifying and distributing it. If you are a software
developer, the best way to support SyncEvolution is to port it to
other backends and systems. Get in touch if you want to hear more
about this.

If you are a (hopefully happy) user of SyncEvolution, then you can
make your appreciation or suggestions for improvements known in
several ways. Although SyncEvolution is free, this does not mean that
its development did not cost much effort - quite the opposite, a lot
of time went into it.

- Send a postcard to the author (see main page).
- Leave comments on the author's blog (http://www.estamos.de/blog).
- Donations are not necessary and cannot be accepted either.


Authors
-------

Patrick Ohly
patrick.ohly@intel.com
http://www.estamos.de/

... plus several others:
http://syncevolution.org/about/contributors

To contact the project publicly (preferred):
syncevolution@syncevolution.org

For confidential emails there is a team mailing list:
syncevolution@lists.intel.com