vtkSlicerXYZNodeis a storable node that represents the data from file (e.g. [vtkMRMLModelNode)
vtkSlicerXYZStorageNodeis the file reader. It populates the storable node using the method
vtkSlicerXYZsLogicis the MRML logic of the
XYZmodule. It exposes a convenient method
AddXYZ(const char* fileName, const char* nodeName=0);that creates a MRML XYZ node (
vtkMRMLXYZNode)and its associated storage node (
vtkMRMLXYZStorageNode), add them into the scene, and call
vtkMRMLXYZStorageNode::ReadData(vtkMRMLStorableNode*,bool);on the storage node to load the file. If the loading fails, it removes the previously created nodes from the scene.
qSlicerXYZsIOis a plugin that is registered by modules into the
qSlicerCoreIOManager. It is the interface between Qt and MRML logics. It internally calls
qSlicerXYZsIOOptionsWidgetis a widget that sets loading options that gets passed to the logic.
qSlicerCoreIOManageris the central class where any IO operation must go through. qSlicerIOs can be registered using
qSlicerCoreIOManager::registerIO(qSlicerIO*)and nodes can be loaded using
qSlicerCoreIOManager::loadNodes(...). It exposes a set of convenient methods such as "what reader must be used for what file".
qSlicerDataDialogis the dialog that allows the user to select the files to load.
How to add support for reading a new file format ?
- Write method
vtkMRMLXYZStorageNode::ReadDataInternal(vtkMRMLStorableNode*, bool temporary);
- Write method
vtkMRMLXYZsLogic::AddXYZ(const char* fileName, const char nodeName =0);
- Write class
- Optional: Write class
qSlicerXYZsIOOptionsWidgetif you want the user to optionally specify loading options.
qSlicerXYZsModule::setup(), instantiate and register
- Add file format to [Documentation/Nightly/SlicerApplication/SupportedDataFormat|SupportedDataFormat] wiki page
In order to inform the user what data has been changed since it was last read, a ModifiedSinceRead mechanism is in place to track when was the file last read and when was the data last modified. If a modification happened , the storable node
vtkMRMLStorableNode::GetModifiedSinceRead() must return true. If the data in the node is the same as in the file, then
vtkMRMLStorableNode::GetModifiedSinceRead() must return false.
vtkMRMLStorageNode keeps track of when a file was last read or written (
vtkMRMLStorableNode keeps track of when the data was last modified (
vtkTimeStamp vtkMRMLStorableNode::StorableModifiedTime). Anytime a
vtkMRMLStorableNode property that is saved in file is modified, the
StorableModifiedTime time stamp must be modified.
At exit time (
vtkMRMLStorableNode::GetModifiedSinceRead() is called to check if the data in the node is the same as in the file or if it has been modified after the file was last read or written. It internally checks
vtkTimeStamp* vtkMRMLStorageNode::StoredTime and
vtkTimeStamp vtkMRMLStorableNode::StorableModifiedTime. If the data is more recent, then a message dialog is shown to the user telling him that some data is different from file; leaving without saving will loose the changes.
How to read files programmatically
qSlicerCoreIOManager* coreIOManager = qSlicerCoreApplication::application()->coreIOManager(); qSlicerIO::IOProperties fileParameters; fileParameters["filename"] = "/path/of/file.ext"; vtkMRMLNode* volumeNode = coreIOManager->loadNodesAndGetFirst("ModelFile", parameters);
Works also with "VolumeFile", "TransformFile", "SceneFile"...
>>> volumeNode = slicer.util.loadVolume('/path/of/file.ext') >>> ...
It works also with loadModel, loadTransform, loadScene...
The mechanism is similar to Read.
qSlicerXYZWriter must implemented.
By default, all the IOs must be done through
qSlicerDataDialog for reading files and
qSlicerSaveDataDialog for writting files. However, due to historical reasons, it is possible to have custom dialogs for each node types.