[Kimchi-devel] [PATCH] UI enhancement: Request /config/capabilities as soon as possible

[Aline Manera]

On 08/08/2014 03:29 PM, Crístian Viana wrote:
> I like the idea to run "kimchi.getCapabilities" only once and use its 
> results later. Those values are very unlikely to change unless there 
> is some server upgrade.
>
> But as far as I understand, there is no syncing strategy to make sure 
> the new variable "kimchi.capabilities" will only be read when the 
> function "kimchi.getCapabilities" has been executed successfully. This 
> may lead to an execution error (i.e. "kimchi.capabilities" may still 
> be undefined) or inconsistent values (e.g the host may have QEMU 
> stream capability but if the function "kimchi.getCapabilities" hasn't 
> finished executing yet, "kimchi.capabilities.qemu_stream" might still 
> have its default value - not the actual one).
>

According to the code, the /config/capabilities request will be the 
first request made while entering the templates tab.
So if it takes time to complete the templates will not be listed and 
kimchi.capabilities not used.



> Also, if the approach is to run "kimchi.getCapabilities" once and then 
> cache its results, we might as well use those cached values elsewhere 
> in Kimchi. The tab "Host" will still execute that function.
>

The host tab uses values that can be changed any time without requiring 
to restart Kimchi.
Because that we can not do the same there.
For example, host tab checks for sosreport tool and if user installs it 
later it does not trigger a kimchi restart so we always need to care 
this info,

> On 08-08-2014 14:15, Aline Manera wrote:
>> /config/capabilities was requested twice for the templates tab: one
>> request to identify if qemu has spice support and other one to identify
>> if the qemu has ISO streaming support.
>>
>> Those requests were made right before using the information, causing a
>> delay on UI until get the server response.
>>
>> For example, for distant servers, while creating a new template the
>> "Remote ISO" option was disabled at the first time and after some 
>> time it was
>> enabled.
>> The same behavior was identified while editing a template, as the 
>> graphics
>> options blinked to add the spice on it.
>>
>> To fix it, request /config/capabilities when loading the templates 
>> tab to have
>> this information prior to edit or create a new template.
>>
>> Signed-off-by: Aline Manera <alinefm at linux.vnet.ibm.com>