Re: Loosing assertions

Hi Axel,

Thanks, I'm being an idiot had had forgotten that it would just assert a 
new arc not replace it.

I have tried change() instead using the code below, but I still do end 
up with two arcs instead of the original one when I iterate through them.


var resource = nsIRDFService.GetResource( resource );
var property = nsIRDFService.GetResource( property );

var oldTarget = ds.GetTarget( resource, property, true );
var newTarget = nsIRDFService.GetLiteral( "NewVal" );

ds.Change( resource, property, oldTarget, newTarget );

var nsEnum = ds.GetTargets( resource, property, true );

// Check
while( nsEnum.hasMoreElements() )	{
   var target = nsEnum.getNext();
   target = target.QueryInterface( Components.interfaces.nsIRDFLiteral );
   alert( "Object: " +target.Value );		// Two assertions
}


Am I missing something again?

Cheers,

N



Axel Hecht wrote:
> Neil Stansbury wrote:
> 
>> Hi all,
>>
>> I am loading a number of datasources from both local files and remote 
>> URLs into a composite datasource.
>>
>> The individual datasources are retrieved via:
>>
>> nsIRDFService.GetDataSource( nsIIOService.NewfileUri )
>> or
>> nsIRDFService.GetDataSource( http URL )
>>
>> I am now trying to assert changes manually into the composite ds 
>> rather than refreshing the entire remote datasources.
>>
>>
>> The odd thing is when I assert() into the composite DS, I know the 
>> assertion works initially as I have CSS selectors that change as soon 
>> as the assertion completes. But when I check the value immediately 
>> after, it is as it was.
>>
>>
>>
>> For example:
>>
>> var nsIRDFService = 
>> Components.classes["@mozilla.org/rdf/rdf-service;1"].getService();
>>
>> var nsIRDFService =
>>   nsIRDFService.QueryInterface(Components.interfaces.nsIRDFService);
>>
>> var subject =
>>   nsIRDFService.GetResource(subject);
>>
>> var predicate =
>>   nsIRDFService.GetResource(predicate);
>>
>> var object = CompDS.GetTarget(subject, predicate, true);
>>
>> var value = object.QueryInterface(Components.interfaces.nsIRDFLiteral);
>>
>> alert( value );
>>
>>
>> value = "new value"
>>
>> var literal = nsIRDFService.GetLiteral(value);
>>
>> CompDS.Assert(subject, predicate, literal, true);
>>
>> // Check
>> object = CompDS.GetTarget(subject, predicate, true);
>> value = object.QueryInterface(Components.interfaces.nsIRDFLiteral);
>>
>> alert( value );        // Still old value
>>
> 
> you end up with
> 
>  foo -> bar -> lit1
>     |-> bar -> lit2
> 
> This does make foo -> bar -> lit2 true, but the first target is still lit1.
> 
> Do you want to Change instead of Assert? Or use GetTargets and pick the 
> right one.
> 
> Axel