How to know if node exist

Programming Questions C++ API
1

Hello team,

Hope you are doing well.

I have a question that seem to be rather easy, but I can’t find the answer… I have multiple camera without the same firmware. They have a few nodes that the name isn’t the same (exposure time abs and exposure time for example).

So my question is : how can I know if a node exist ? Like if I want to use ExposureTime node, is there a device->Nodes()->Exist(“Std::ExposureTime”); ? or maybe there is another way to know that ?

For now, the only way I get is to use a try catch for each node… That seems rather badly.

Thanks in advance.

Cheers,
Axel

2

Hi @AxelDosSantosDoAlto,

if you dont want to stick with the general way of handling CvbExceptions, you could try the following:

https://help.commonvisionblox.com/NextGen/14.1/cvbpp/dd/dff/class_cvb_1_1_gen_api_1_1_node_map.html#a82d6ac7e2d944dd0310b2c1bdcc65a5e

The NodeMap class has a Nodes() function that basically gives you a dictionary of all Nodes in the NodeMap.
So with this information you can check if the node you are looking for is on your NodeMap bevorehand.

Cheers
Chris

3

With CVB 14.1 you can also use the TryGetNode function like this:

if (auto intNode = devNodeMap_->TryGetNode<Cvb::IntegerNode>(featureName))
{

}
1 Like
4

Hello guy,

Sorry for my late answer. Everything is ok for me thanks to @Sebastian and the TryGetNode method !

Thanks you very much.

There is an exemple of how I’m dealing with the nodes for whoever need an exemple :

[...]
m_node_scpsp_packet_size = getCvbIntegerNode("TLDevice", "PacketSize");
if (m_node_scpsp_packet_size == nullptr)
	throw std::runtime_error("Error with node PacketSize / TLDevice.");
[...]

where

[...]
const std::string m_node_name_for_device = "Device";
[...]
Cvb::IntegerNodePtr CCameraCvbGenicam::getCvbIntegerNode(std::string node_map_name, std::string node_name) {
	return m_device->NodeMap(node_map_name)->TryGetNode<Cvb::IntegerNode>(node_name);
}
[...]
``