Re: [SyncEvolution] syncevolution and a radicale caldev server
by Patrick Ohly
On Fri, 2012-02-17 at 15:14 +0100, Gregor Horvath wrote:
> Am Fri, 17 Feb 2012 11:12:52 +0100
> schrieb Patrick Ohly <patrick.ohly(a)intel.com>:
>
> > On Tue, 2012-02-14 at 15:57 +0100, Patrick Ohly wrote:
> > > But as Radicale is an example where multiple databases are possible
> > > (in
> > > contrast to Google), it's worth spelling out explicitly how such a
> > > config can be created:
> >
> > [...]
> >
> > William, did this work?
> >
> > Perhaps you (or someone else) has the time to turn the instructions
> > into a proper HOWTO? I created a place holder Wiki page for it here:
> > http://syncevolution.org/wiki/synchronizing-radicale
> >
> >
William sent me some debug logs, but then ran out of time. So I've
installed Radicale myself and found an issue that'll break
SyncEvolution: items reported by the server include double slashes in
the path.
<multistatus xmlns="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav">
<response>
<href>/public_user/calendar/calendar_1//1234567890(a)dummy.ics</href>
^^
SyncEvolution will then use /1234567890(a)dummy.ics as path in future
requests, which Radicale rejects with either 404 or 401 errors.
I'll work around that in SyncEvolution. I'm not sure whether there is a
solution with 1.2.2.
Have you considered Calypso (http://keithp.com/blogs/calypso/)? I don't
know yet whether it works with SyncEvolution; if there is interest, then
I will try it.
> I am trying to do the same thing (with one calender to start with)
> N900 <-> radicale but it did not work, because it seems the Maemo
> calendar is not found:
>
> http://pastebin.com/huMXDsEx
>
> What I am doing wrong?
You have additional spaces after your \ character. The slash must be at
the end of each line.
--
Best Regards, Patrick Ohly
The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.
5 years, 7 months
[SyncEvolution] documentation update, enhanced command line
by Patrick Ohly
Hello!
The "Getting the concepts clear" mail thread and a private email
exchange with Todd identified several shortcomings in the documentation
and/or implementation. This is my attempt to address those. A diff and
the full modified README.rst are attached.
Some of these changes will require changes in the implementation.
In short, what I am trying to achieve is:
* Better explain what local sync is and how it involves two sync
configs. "originating config" gets introduces instead of just
"sync config".
* Better explain the relationship between contexts, sync configs,
and source configs ("a sync config can use the source configs in
the same context").
* An entire section on config properties in the terminology
section.
* Less focus on conflict resolution, as suggested by Graham.
* Remove the hard-coded "target-config" name. It still needs to be
there as fallback for existing configs or users continuing to
use the current instructions.
* Fix examples that became invalid when fixing the password
storage/lookup mechanism for GNOME keyring in 1.4. I noticed
that the username=email-address part should be handled without
additional properties.
* Fix WebDAV with DNS auto-discovery. Few servers support it, so
this hasn't been noticed before.
* Fix the implicit command line magic where it does some
consistency checks when creating new configs. Not exactly sure
yet how.
I ran out of stream after updating the terminology section, the "command
line conventions", "Synchronization beyond SyncML" and "CalDAV and
CardDAV". It's possible that the other sections also contain slightly
incorrect usage of the terminology or are simply out-dated.
--
Best Regards, Patrick Ohly
The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.
6 years, 2 months
[SyncEvolution] SyncML <-> CardDAV: UID handling
by Patrick Ohly
Hello!
Who is using SyncEvolution as gateway between a SyncML client and a
CardDAV server? Which client?
I am currently updating the CardDAV backend and would like to remove
some UID handling hacks that did not work in all cases anyway.
The problem is that these hacks might be needed for SyncML clients which
claim to support UID while in fact they rewrite the UID and then send
some other UID back during an update. This then becomes a problem on the
CardDAV side because some CardDAV servers (for example, Apple Calendar
server) do not allow changing the UID during an update.
I don't know whether there are such broken SyncML clients, though, and
therefore I intend to go ahead with the change.
--
Best Regards, Patrick Ohly
The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.
6 years, 3 months
Re: [SyncEvolution] documentation update, enhanced command line - second attempt
by Emiliano Heyns
On 23/05/2014 13:02:04, "Patrick Ohly" <patrick.ohly(a)intel.com> wrote:
>As a reminder, we agreed on some aspects:
> * Better explain what local sync is and how it involves two sync
> configs. "originating config" gets introduces instead of just
> "sync config".
> * "data source" -> "datastore"
> * Better explain the relationship between contexts, sync configs,
> and source configs ("a sync config can use the source configs
>in
> the same context").
> * An entire section on config properties in the terminology
> section.
> * Less focus on conflict resolution, as suggested by Graham.
> * Remove the hard-coded "target-config" name. It still needs to
>be
> there as fallback for existing configs or users continuing to
> use the current instructions.
I'm personally not so keen on the last one anymore. I agree it's
arbitrary, but it's just convention-over-configuration, and there's
already so much to configure in SyncEvolution.
>I had also proposed to revise some of the magic that --configure does
>when setting up a new config. I'm backing off of that and want to keep
>the behavior as it is at the moment, because I am not sure how some
>things should work without that magic.
That's OK I think, as long as we can document that magic so it's
behavior is predictable.
>Here's the list of changes made since I first proposed the revised
>README.rst:
>
> "datastore" avoids that misconception.
>
> "data store" in two words could also have been used; not sure which
> spelling is better.
I think "datastore" is better. As a single term, is indicates a
SyncEvolution concept. As two words, it seems to indicate a more general
term that is not so tied to SyncEvolution.
>
> Avoid "access a peer" when talking about a sync config, because
> "access" implies that sync is initiated using the sync config,
>which
> is not the case for SyncML server sync configs in a
>client-initiated
> sync. "talk with peer" is more neutral.
Agreed.
Emile
6 years, 4 months
Re: [SyncEvolution] Syncing two servers - Zimbra
by Patrick Ohly
On Mon, 2014-04-14 at 09:53 +0200, Patrick Ohly wrote:
> So the root problems are that a) SyncEvolution does a search for
> calendars and b) that this takes a long time with the Zimbra server and
> eventually fails. The exact reason for both remains to be seen.
[...]
> When checking the principle URL, it should
> only look for meta information like the calendar-home-set (= the URL
> under which calendars are found).
>
> There's nothing wrong with having a principal URL that contains
> collections. I've not seen it done like that elsewhere, though, and you
> seem to be first one to test with Zimbra.
The revised WebDAV search in SyncEvolution 1.4.99.2 should take this
into account. I hope that it is now fast with Zimbra, too, but haven't
actually tested it with Zimbra.
Todd, can you give that new version a spin and report back?
I'm not sure whether we really need to change the current --configure
behavior. For now I'd prefer to keep it as it is.
--
Best Regards, Patrick Ohly
The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.
6 years, 4 months
[SyncEvolution] SyncEvolution 1.4.99.2
by Patrick Ohly
About 1.4.99.2
==============
1.4.99.2 is a new development snapshot. It enhances interoperability
with CardDAV servers and in particular Google Contacts considerably.
Contact data gets converted to and from the format typically used by
CardDAV servers, so now anniversary, spouse, manager, assistant and
instant message information are exchanged properly.
Categories are not supported by Google CardDAV and thus still get lost.
Custom labels get stored in EDS as extensions and no longer get lost
when updating some other aspects of a contact. However, Evolution does
not show custom labels and removes them when editing a property which
has a custom label (BGO #730636).
Scanning for CardDAV/CalDAV resources was enhanced. It now finds
additional calendars with Google CalDAV and works with iCloud.
However, syncing with iCloud ran into a server bug (reported as
17001498 "CalDAV REPORT drops calendar data") and needs further work.
The Ubuntu Online Accounts backend was added to syncevolution.org
binaries, targeting Ubuntu Saucy and later.
Details:
* vcard profile: avoid data loss during merging
When resolving a merge conflict, repeating properties were taken
wholesale from the winning side (for example, all email addresses). If
a new email address had been added on the loosing side, it got lost.
Arguably it is better to preserve as much data as possible during a
conflict. SyncEvolution now does that in a merge script by checking
which properties in the loosing side do not exist in the winning side
and copying those entries.
Typically only the main value (email address, phone number) is checked
and not the additional meta data (like the type). Otherwise minor
differences (for example, both sides have same email address, but with
different types) would lead to duplicates.
Only addresses are treated differently: for them all attributes
(street, country, city, etc.) are compared, because there is no single
main value.
* engine: UID support in contact data
Before, the UID property in a vCard was ignored by the engine.
Backends were responsible for ensuring that the property is
set if required by the underlying storage. This turned out to be
handled incompletely in the WebDAV backend.
This change moves this into the engine:
- UID is now field. It does not get used for matching
because the engine cannot rely on it being stored
by both sides.
- It gets parsed if present, but only generated if
explicitly enabled (because that is the traditional
behavior).
- It is never shown in the DevInf's CtCap
because the Synthesis engine would always show it
regardless whether a rule enabled the property.
That's because rules normally only get triggered
after exchanging DevInf and thus DevInf has to
be rule-independent. We don't want it shown because
then merging the incoming item during a local sync
would use the incoming UID, even if it is empty.
- Before writing, ensure that UID is set.
When updating an existing item, the Synthesis engine reads
the existing item, preserves the existing UID unless the peer
claims to support UID, and then updates with the existing UID.
This works for local sync (where SyncEvolution never claims
to support UID when talking to the other side). It will break
with peers which have UID in their CtCap although they
rewrite the UID and backends whose underlying storage cannot
handle UID changes during an update (for example, CardDAV).
* CardDAV: use Apple/Google/CardDAV vCard flavor
In principle, CardDAV servers support arbitrary vCard 3.0
data. Extensions can be different and need to be preserved. However,
when multiple different clients or the server's Web UI interpret the
vCards, they need to agree on the semantic of these vCard extensions.
In practice, CardDAV was pushed by Apple and Apple clients are
probably the most common clients of CardDAV services. When the Google
Contacts Web UI creates or edits a contact, Google CardDAV will
send that data using the vCard flavor used by Apple.
Therefore it makes sense to exchange contacts with *all* CardDAV
servers using that format. This format could be made configurable in
SyncEvolution on a case-by-case basis; at the moment, it is
hard-coded.
During syncing, SyncEvolution takes care to translate between the
vCard flavor used internally (based on Evolution) and the CardDAV
vCard flavor. This mapping includes:
X-AIM/JABBER/... <-> IMPP + X-SERVICE-TYPE
Any IMPP property declared as X-SERVICE-TYPE=AIM will get
mapped to X-AIM. Same for others. Some IMPP service types
have no known X- property extension; they are stored in
EDS as IMPP. X- property extensions without a known X-SERVICE-TYPE
(for example, GaduGadu and Groupwise) are stored with
X-SERVICE-TYPE values chosen by SyncEvolution so that
Google CardDAV preserves them (GroupWise with mixed case
got translated by Google into Groupwise, so the latter is used).
Google always sends an X-ABLabel:Other for IMPP. This is ignored
because the service type overrides it.
The value itself also gets transformed during the mapping. IMPP uses
an URI as value, with a chat protocol (like "aim" or "xmpp") and
some protocol specific identifier. For each X- extension the
protocol is determined by the property name and the value is the
protocol specific identifier without URL encoding.
X-SPOUSE/MANAGER/ASSISTANT <-> X-ABRELATEDNAMES + X-ABLabel
The mapping is based on the X-ABLabel property attached to
the X-ABRELATEDNAMES property. This depends on the English
words "Spouse", "Manager", "Assistant" that Google CardDAV
and Apple devices seem to use regardless of the configured
language.
As with IMPP, only the subset of related names which have
a corresponding X- property extension get mapped. The rest
is stored in EDS using the X-ABRELATEDNAMES property.
X-ANNIVERSARY <-> X-ABDATE
Same here, with X-ABLabel:Anniversary as the special case
which gets mapped.
X-ABLabel parameter <-> property
CardDAV vCards have labels attached to arbitrary other properties
(TEL, ADR, X-ABDATE, X-ABRELATEDNAMES, ...) via vCard group tags:
item1.X-ABDATE:2010-01-01
item1.X-ABLabel:Anniversary
The advantage is that property values can contain arbitrary
characters, including line breaks and double quotation marks,
which is not possible in property parameters.
Neither EDS nor KDE (judging from the lack of responses on the
KDE-PIM mailing list) support custom labels. SyncEvolution could
have used grouping as it is done in CardDAV, but grouping is not
used much (not at all?) by the UIs working with the vCards in EDS
and KDE. It seemed easier to use a new X-ABLabel parameter.
Characters which cannot be stored in a parameter get converted
(double space to single space, line break to space, etc.) during
syncing. In practice, these characters don't appear in X-ABLabel
properties anyway because neither Apple nor Google UIs allow entering
them for custom labels.
The "Other" label is used by Google even in case where it adds no
information. For example, all XMPP properties have an associated
X-ABLabel=Other although the Web UI does not provide a means to edit
or show such a label. Editing the text before the value in the UI
changes the X-SERVICE-TYPE parameter value, not the X-ABLabel as for
other fields.
Therefore the "Other" label is ignored by removing it during syncing.
X-EVOLUTION-UI-SLOT (the parameter used in Evolution to determine the
order of properties in the UI) gets stored in CardDAV. The only exception
is Google CardDAV which got confused when an IMPP property had both
X-SERVICE-TYPE and X-EVOLUTION-UI-SLOT parameters set. For Google,
X-EVOLUTION-UI-SLOT is only sent on other properties and thus ordering
of chat information can get lost when syncing with Google.
* synccompare: support grouping and quoted parameter strings
Grouped properties are sorted first according to the actual property
name, then related properties are moved to the place where their group
tag appears first. The first grouped property gets a "- " prefix, all
following ones are just indended with " ". The actual group tag is not
part of the normalized output, because its value is irrelevant:
BDAY:19701230
- EMAIL:john@custom.com
X-ABLabel:custom-label2
...
FN:Mr. John 1 Doe Sr.
- IMPP;X-SERVICE-TYPE=AIM:aim:aim
X-ABLabel:Other
...
- X-ABDATE:19710101
X-ABLabel:Anniversary
Redundant tags (those set for only a single property, X-ABLabel:Other)
get removed as part of normalizing an item.
* WebDAV: use server's order when listing collections
When doing a recursive scan of the home set, preserve the order of
entries as reported by the server and check the first one first. The
server knows better which entries are more relevant for the user (and
thus should be the default) or may have some other relevant
order. Previously, SyncEvolution replaced that order with sorting by
URL, which led to a predictable, but rather meaningless order.
For example, Google lists the users own calendar first, followed by
the shared calendars sorted alphabetical by their name. Now
SyncEvolution picks the main calendar as default correctly when
scanning from https://www.google.com/calendar/dav/.
* WebDAV: improved database search (Google, Zimbra)
Zimbra has a principal URL that also serves as home set. When using it
as start URL, SyncEvolution only looked the URL once, without listing
its content, and thus did not find the databases.
When following the Zimbra principal URL indirectly, SyncEvolution did
check all of the collections there recursively. Unfortunately that
also includes many mail folders, causing the scan to abort after
checking 1000 collections (an internal safe guard).
The solution for both includes tracking what to do with a URL. For the
initial URL, only meta data about the URL itself gets
checked. Recursive scanning is only done for the home set. If that
home set contains many collections, scanning is still slow and may run
into the internal safe guard limit. This cannot be avoided because the
CalDAV spec explicitly states that the home set may contain normal
collections which contain other collections, so a client has to do the
recursive scan.
When looking at a specific calendar, Google CalDAV does not report
what the current principal or the home set is and therefore
SyncEvolution stopped after finding just the initial calendar. Now it
detects the lack of meta information and adds all parents also as
candidates that need to be looked at. The downside of this is that it
doesn't know anything about which parents are relevant, so it ends up
checking https://www.google.com/calendar/ and
https://www.google.com/.
In both cases Basic Auth gets rejected with a temporary redirect to
the Google login page, which is something that SyncEvolution must
ignore immediately during scanning without applying the resend
workaround for "temporary rejection of valid credentials" that can
happen for valid Google CalDAV URLs.
* WebDAV: enhanced database search (Google Calendar)
Additional databases where not found for several
reasons. SyncEvolution ignored all shared calendars
(http://calendarserver.org/ns/shared) and Google marks the additional
calendars that way. The other problem was that the check for leaf
collections (= collections which cannot contain other desired
collections) incorrectly excluded those collections instead of only
preventing listing of their content.
With this change,
https://www.google.com/calendar/dav/?SyncEvolution=Google can be used
as starting point for Google Calendar.
* WebDAV: fix database scan on iCloud
The calendar home set URL on iCloud (the one ending in /calendars/) is
declared as containing calendar data. That was enough for
SyncEvolution to accept it incorrectly as calendar. However, the home
set only contains calendar data indirectly.
* WebDAV: support redirects between hosts and DNS SRV lookup based on URL
When finding a new URL, we must be prepared to reinitialize the Neon
session with the new host settings.
iCloud does not have .well-known support on its www.icloud.com
server. To support lookup with a non-icloudd.com email address, we
must do DNS SRV lookup when access to .well-known URLs fails. We do
this without a www prefix on the host first, because that is what happens
to work for icloud.com.
With these changes it becomes possible to do database scans on Apple
iCloud, using syncURL=https://www.icloud.com or
syncURL=https://icloud.com. Giving the syncURL like this is only
necessary for a username that does not end in @icloud.com. When
the syncURL is not set, the domain for DNS SRV lookup is taken
from the username.
* WebDAV: more efficient item creation
PUT has the disadvantage that a client needs to choose a name and then
figure out what the real name on the server is. With Google CardDAV that
requires sending another request and only works because the server happens
to remember the original name (which is not guaranteed!).
POST works for new items without a name and happens to be implemented
by Google such that the response already includes all required
information (new name and revision string).
POST is checked for as described in RFC 5995 once before creating a new
item. Servers which don't support it continue to get a PUT.
* WebDAV: send "User-Agent: SyncEvolution"
Apple iCloud servers reject requests unless they contain a User-Agent
header. The exact value doesn't seem to matter. Making the string
configurable might be better, but can still be done later when it
is more certain whether and for what it is needed.
* WebDAV: refactor and fix DNS SRV lookup
The syncevo-webdav-lookup script was not packaged. It did not report
"not found" DNS results correctly and the caller did not check for
this either, so when looking up the information for a domain which
does not have DNS SRV entries, SyncEvolution ended up retrying for
while as if there had been a temporary lookup problem.
* signon: make Accounts optional
The new "signon" provider only depends on lib[g]signon-glib. It uses
gSSO if found, else UOA. Instead of pulling parameters and the
identity via libaccounts-glib, the user of SyncEvolution now has to
ensure that the identity exists and pass all relevant parameters
in the "signon:" username.
* gSSO: adapt to gSSO >= 2.0
* config templates: Funambol URLs
Funambol turned of the URL redirect from my.funambol.com to
onemedia.com. The Funambol template now uses the current URL. Users
with existing Funambol configs must updated the syncURL property
manually to https://onemediahub.com/sync
Kudos to Daniel Clement for reporting the change.
* command line: fix --update from directory
The "--update <dir name>" operation was supposed to take the
item luids from the file names inside the directory. That part
had not been implemented, turning the operation accidentally
into an "--import".
Also missing was the escaping/unescaping of luids. Now the
same escaping is done as in command line output and command
line parsing to make the luids safe for use as file name.
* testing: added server-specific tests for CardDAV covering
remote item formats and edit conflicts.
Upgrading from releases <= 1.3.99.4:
------------------------------------
If the value of "username/databaseUser/proxyUser" contains a colon,
the "user:" prefix must be added to the value, to continue treating it
like a plain user name and not some reference to an unknown identity
provider (like "id:", "goa:", "signon:", etc.).
The lookup of passwords in GNOME Keyring was updated slightly in
1.3.99.5. It may be necessary to set passwords anew if the old one is
no longer found.
Upgrading from release 1.2.x:
-----------------------------
The sync format of existing configurations for Mobical (aka Everdroid)
must be updated manually, because the server has encoding problems when
using vCard 3.0 (now the default for Evolution contacts):
syncevolution --configure \
syncFormat=text/x-vcard \
mobical addressbook
The Funambol template explicitly enables usage of the
"refresh-from-server" sync mode to avoid getting throttled with 417
'retry later' errors. The same must be added to existing configs
manually:
syncevolution --configure \
enableRefreshSync=TRUE \
funambol
Upgrading from releases before 1.2:
-----------------------------------
Old configurations can still be read. But writing, as it happens
during a sync, must migrate the configuration first. Releases >= 1.2
automatically migrates configurations. The old configurations
will still be available (see "syncevolution --print-configs") but must
be renamed manually to use them again under their original names with
older SyncEvolution releases.
Source, Installation, Further information
=========================================
http://syncevolution.org/blogs/pohly/2014/syncevolution-14992-released
Source code bundles for users are available in
http://downloads.syncevolution.org/syncevolution/sources
and the original source is in the git repositories
http://cgit.freedesktop.org/SyncEvolution/
i386, lpia and amd64 binaries for Debian-based distributions are
available via the "unstable" syncevolution.org repository. Add the
following entry to your /apt/source.list:
deb http://downloads.syncevolution.org/apt unstable main
Then install "syncevolution-evolution", "syncevolution-kde" and/or
"syncevolution-activesync".
These binaries include the "sync-ui" GTK GUI and were compiled for
Ubuntu 10.04 LTS (Lucid), except for ActiveSync binaries which were
compiled for Debian Wheezy, Ubuntu Saucy and Ubuntu Trusty. A backend
for Ubuntu Online Accounts was compiled on Ubuntu Saucy. The packages
mentioned above are meta-packages which pull in suitable packages
matching the distro during installation.
Older distributions like Debian 4.0 (Etch) can no longer be supported
with precompiled binaries because of missing libraries, but the source
still compiles when not enabling the GUI (the default).
The same binaries are also available as .tar.gz and .rpm archives in
http://downloads.syncevolution.org/syncevolution/. In contrast
to 0.8.x archives, the 1.x .tar.gz archives have to be unpacked and the
content must be moved to /usr, because several files would not be found
otherwise.
After installation, follow the
http://syncevolution.org/documentation/getting-started steps.
--
Patrick Ohly, on behalf of everyone who has helped
to make SyncEvolution possible:
http://syncevolution.org/about/contributors
6 years, 4 months
[SyncEvolution] merging of winning and loosing items
by Patrick Ohly
Hello!
I'm currently writing tests for handling of conflicts. This wasn't done
earlier because SyncEvolution's test suite primarily targeted syncing
with SyncML servers, and behavior of those was out of control anyway.
With local syncing and/or SyncEvolution as HTTP server that's different.
My main concern at the moment are update/update conflicts where both
sides updated the same common item before syncing. libsynthesis
determines the winning item based on age (REV in vCard, LAST-MODIFIED in
iCalendar). That determines which side's single-value properties are
preserved when merging them isn't possible. I already noticed that I
need tests for both cases, because a particular SyncEvolution bug
(https://bugs.freedesktop.org/show_bug.cgi?id=77065) only shows up in
one of the two cases.
How does this apply to arrays? Consider the following scenario: the
client adds a new TEL, the server a new EMAIL (in this order). What I
observe is that the server's item wins, preserving the server's EMAIL,
while the client's TEL array gets overwritten with the server's less
complete TEL array. The new TEL from the client thus gets lost.
That is with the following profile:
<!-- telephone numbers -->
<field name="TEL" array="yes" type="telephone" compare="conflict"/>
<field name="TEL_FLAGS" array="yes" type="integer" compare="conflict"/> <!-- offset 0 -->
<field name="TEL_LABEL" array="yes" type="string" compare="conflict"/> <!-- offset 1 -->
<field name="TEL_ID" array="yes" type="integer" compare="conflict"/> <!-- offset 2 -->
<field name="TEL_SLOT" array="yes" type="integer" compare="never"/> <!-- offset 3 -->
<!-- emails -->
<field name="EMAIL" array="yes" type="multiline" compare="conflict"/>
<field name="EMAIL_FLAGS" array="yes" type="integer" compare="conflict"/> <!-- offset 0 -->
<field name="EMAIL_LABEL" array="yes" type="string" compare="conflict"/> <!-- offset 1 -->
<field name="EMAIL_ID" array="yes" type="integer" compare="conflict"/> <!-- offset 2 -->
<field name="EMAIL_SLOT" array="yes" type="integer" compare="never"/> <!-- offset 3 -->
I suspect that in this case the engine really has no choice other than
treating the entire TEL array as one value. Even if it knew how to merge
the two TEL arrays (which isn't that simple when one also takes
reordering and intentional removal of entries into account), would it
know that the consecutive arrays (TEL and TEL_* resp. EMAIL and EMAIL_*)
are related?
I don't think so. That's something that is specified in the profile, but
not in the field list.
So a merge script will be needed if special handling of TEL and EMAIL is
desired, right?
The problem that I was alluding to earlier is that merging
winning: TEL = [ '1', '2' ] and
loosing: TEL = [ '1', '2', '3' ]
has no unambiguous solution. Was '3' added on the loosing side or was it
removed on the winning one?
If in doubt, probably the best approach is to pick the one which avoids
data loss, i.e. preserve '3'.
Now, consider reordering:
winning: TEL = [ '1', '2' ] and
loosing: TEL = [ '2', '1' ].
Were the entries merely reordered or were the values changed on the
loosing side? In the former case, nothing needs to be done and no
information gets lost. In the later case, the changes made on the client
get lost. I don't see a way around that (*).
Copying extra values from the loosing side can work with reordering by
looking at each value and not just at the end of the array. It's not
perfect, though, when values were edited.
Any comments so far?
(*) A three-way merge where previous copies of client and server items
are available to compute a diff would work, but that increases storage
requirements for rare situations and would require significant changes
to the engine.
--
Best Regards, Patrick Ohly
The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.
6 years, 4 months
[SyncEvolution] Gnome Online Accounts
by Emiliano Heyns
Hey list,
I'm trying to figure out how to get Google OAuth2 credentials in the
hands of SyncEvolution on a headless Ubuntu server. I considered
installing gnome-online-accounts but that pulled in a metric crapload of
dependencies I'd rather not install. Copying the GOA databases from my
desktop to the server didn't work either. Is there any other way I can
hand a token to SyncEvolution? I know I can generate a token on the
server -- google-cl does it too.
Any ideas?
Emile
6 years, 4 months
