check if user has visibility on a thing

[lguagneli84]

Hi all,

 I have a set of things (collected in a infotable) and I would like to know if the current user logged has visibility for each thing in order to show just his thing.

I would like to avoid to use GetImplementingThing function because if I will have a large number of Thing, the service will respond slowly.

Please see code below:

for (var x = 0; x < listLength; x++) {
    var rowPos = list.rows[x];
    var posInstance = Things[rowPos.PosThingName];
    try {
        if(posInstance.name) { result.AddRow(rowPos); }
    } catch(err) {
    }
}

  This will work because the "posInstance.name" will return error 

User does not have visibility permission for....THING_NAME

but this cause a large number of log error in monitoring and I would like to avoid that.

Is there a way to know if current user has visibility permission on a Thing?

[CarlesColl · Accepted solution]

You can use spotlightsearch instead (I don't know the performance...)

Istead of:

try {
        if(posInstance.name) { result.AddRow(rowPos); }
    } catch(err) {
    }

Use:

var any = Resources["SearchFunctions"].SpotlightSearch({
            maxItems: 1,
            searchExpression: rowPos.PosThingName,
            types: { items: ["Thing"] }
           
        });
if (any.rows.length==1)  { result.AddRow(rowPos); }

[PaiChung]

I don't see why GetImplementingThings would be any slower, one way or another you are determining all potential Things and then pulling the ones that are visible.

[wposner-2]

Carles answer is correct.  I've validated and implemented in my current project.  The search services automatically determine user visibility and only return entities to which a user has access.

[lguagneli84]

Because we will have different customer and each customer will have his own set of things that he will be able to see and on which I will have to performe research on the related stream. 

Collecting things in a separate stream and searching on this, it allows me to increase the response speed by an order of magnitude compared to the getImplementedThing. 

[lguagneli84]

This solution works but to increase performance I added a field in my infotable with unitVisibility then I have added a filter in my query specification