Using OpenCMIS (or dotcmis), after getting a Repository object from a repository, how to check whether it has a particular capability?
For instance, whether CapabilityChanges is set to all.
This is a bit nicer:
if ( repository.Capabilities.ChangesCapabilities == CapabilityChanges.All ) { ... }
There is probably a more elegant way to do it, but now I am using this:
if ( repository.Capabilities.ChangesCapabilities.GetCmisValue().Equals("all") )
{ ... }
Related
I'm trying to open an image from memory with the default image viewer on Linux.
The class is part of the share_plus package. I can't figure out how to define the required UrlLauncherPlatform property.
I want to use it like this:
SharePlusLinuxPlugin(urlLauncher).shareXFiles([XFile.fromData(img)]);
I have googled this class, didn't find any usage examples.
From the source code on Github, it looks like shareXFiles() has not been implemented on Linux. To quote:
Future<ShareResult> shareXFiles(
List<XFile> files, {
String? subject,
String? text,
Rect? sharePositionOrigin,
}) {
throw UnimplementedError(
'shareXFiles() has not been implemented on Linux.',
);
}
The same is true for the shareFiles() method.
Aside from that, there is usually no need to call SharePlusLinuxPlugin directly. The Share class is configured in such a way that it automatically detects the platform that it is running on
Let's say I have my NixOS configuration.nix set up as follows:
{config, pkgs, ...}:
{
services.openssh.enable = true;
}
I now want to have a second file called networking.nix which sets my hostname based on an argument.
{config, pkgs, hostname, ...}:
{
networking.hostName = hostname
}
Is this possible? How can I include the file. I already tried doing it by using imports = [ ./networking.nix { hostname = "helloworld"; } ]; but that didn't work.
Thanks.
A 'NixOS configuration file' is simply a module that doesn't define options, so there is really no distinction. A configuration.nix file is just a module, and typically it does not define any options, so it can be written in the abbreviated form.
Defining options is the normal way for NixOS modules to pass information around, so that's the most idiomatic way to go about.
However, if you really must, for some very special reason, because you're doing very unusual things with NixOS, you can put arbitrary functions in imports. But you shouldn't, because it doesn't work well with the module system's custom error messages and potentially other aspects that rely on knowing where a module is defined. If you do so, do make sure it is an actual function. In your case, that would imply modifying the first line of networking.nix to make it a curried function:
hostname: {config, pkgs, ...}:
Not very pretty in my opinion. Although it is very explicit about what is going on, it deviates from what is to be expected of a NixOS module.
I encountered this problem today and came up with a fairly simple solution recommended in the manual.
foobar.nix
{ lib, withFoo ? "bar", ... }:
# simple error checking to ensure garbage isn't passed in
assert lib.asserts.assertOneOf "withFoo" withFoo [
"bar"
"baz"
# other valid choices ...
];
{
# ...
}
configuration.nix
args#{ ... }:
{
imports = [
# ...
(
import ./foobar.nix (
args
// { withFoo = "baz"; }
)
)
# ...
];
}
This is ideal for 'one off' options in your configurations.
You should be able to use the _module.argsoption [1] to do that. So your configuration.nix would be like:
{config, pkgs, ...}:
{
_module.args.hostname = "ahostname";
services.openssh.enable = true;
}
However where the values are very simple it will probably be much easier to just set them directly, e.g. just define networking.hostname in configuration.nix. This section of the manual re. merging and priorities may be helpful also [2].
Further discussion:
The value of _module.args is indeed applied to all imported configurations (though the value will only be used in modules that directly refer to it, such as the pkgs value, the ... represents all the values that aren't referenced).
For passing arguments to modules it seems a good approach to me, but from your comments perhaps a different approach might be more suitable.
Another solution could be to flip the relationship in the imports: rather than a single common config that passes multiple different arguments instead multiple different configs import the common configuration. E.g.
$cat ./common.nix
{ services.openssh.enable = true; }
$cat ./ahostname.nix
{ imports = [ ./common.nix ]; networking.hostname = "ahostname"; }
The NixOS config in this Reddit comment looks like it uses this approach. There are quite a few other NixOS configurations that people have shared publicly online so you might find some useful ideas there. The points in the answer from Robert Hensing are very useful to bear in mind as well.
However it's hard to say what might be a better solution in your case without knowing a bit more about the context in which you want to use it. You could create a new SO question with some more information on that which might make it easier to see a more appropriate solution.
I'm writing some puppet modules and have a package defined in two modules hence get the following error:
err: Could not retrieve catalog from remote server: Error 400 on SERVER: Duplicate definition: Package[gnome-session-fallback] is already defined in file /etc/puppet/modules/vnc4server/manifests/init.pp at line 3; cannot redefine at /etc/puppet/modules/vino/manifests/init.pp:7 on node l
Hence want to ensure that the package has not already been defined but the following does not work:
if ! defined ('gnome-session-fallback') {
package { 'gnome-session-fallback':
ensure => installed,
}
}
Can anyone suggest how to fix this, and on the broader scale, what is the "proper" approach to avoiding clashes such as this in modules?
You are missing Package[] inside defined(). The correct way to do it:
if ! defined(Package['gnome-session-fallback']) {
package { 'gnome-session-fallback':
ensure => installed,
}
}
The cleanest way to do this is to use the ensure_resource function from puppetlabs-stdlib:
ensure_resource('package', 'gnome-session-fallback', {'ensure' => 'present'})
To answer my own question about what the "proper" approach is : This issue is discussed at https://groups.google.com/forum/?fromgroups=#!topic/puppet-users/julAujaVsVk and jcbollenger offers what looks like a "best-practice" solution - resources which are defined multiple times should be moved into their own module and included into the classes on which they depend. I applied this and solved my problem.
This doesn't actually answer why "if !defined" fails however...
One cleaner way (among multiple ways) is to create a virtual package resource and then realize it. You can realize the same virtual package multiple times without error.
#package { 'gnome-session-fallback':
ensure => installed,
}
And then where you need it:
realize( Package[ 'gnome-session-fallback' ] )
According to the Puppet documentation:
Order does not matter in a declarative language.
If that is the case, why does this bit of code work:
class myserver {
$package_to_install = 'libcapture-tiny-perl'
package {
$package_to_install: ensure => present;
}
}
but this code does not work:
class myserver {
package {
$package_to_install: ensure => present;
}
$package_to_install = 'libcapture-tiny-perl'
}
If order matters, then I can see why one works and the other does not, but since order does not matter, why do they behave differently?
Disclaimer: I am one of the Puppet developers.
Because our language isn't, as our documentation claims, actually declarative. It is actually ordered. :(
Evaluation is more or less top to bottom inside the class or declaration. The product of that evaluation is a resource in the catalog, however, not evaluation of the catalog.
Think of the DSL as a not-entirely-declarative way to build the catalog, a graph of resources, that are entirely declarative in processing.
All,
Could you explain me about Monitor Class, esp following code in more detail?
if (Monitor.TryEnter(CashDrawers.lockObject))
{
try
{
// Work here
}
finally
{
Monitor.Exit(lockObject);
}
}
Thanks,
CK
Not sure if this is what you're looking for but...
The code you posted in your question is the non blocking version of
lock(CashDrawers.LockObject)
{
//work here
}
Meaning that it will only do it's "work" if it is able to acquire the lock on the first try. If something else already has the lock, then your code won't do anything. I'm assuming this code is written within the CashDrawers class, otherwise you probably have a transcription error in that you need to Moniter.Exit on the same object that you Entered on.
Are you looking for an explanation on synchronization in general? If so that's beyond the scope of what I can write in an answer. Please check out http://www.albahari.com/threading/part2.aspx for some general synchronization info in .net.