Short description about VNA format can be found on Gephi website.
VnaExporter is available in Pharo 3 configuration browser.
You can also load it executing is a workspace:
Gofer it
smalltalkhubUser: 'Pharo'
project: 'MetaRepoForPharo30';
configurationOf: 'VnaExporter';
loadStable.
###Setup
First create a new instance of exporter: exporter := VnaExporter new.
To add nodes use:
exporter addNode: anObject.
exporter addNodes: aCollection.
exporter model: aCollection "overrides whole nodes set"
To add edges use:
exporter addEdge: aPair.
exporter addEdges: aCollectionOfPairs.
exporter edges: aCollectionOfPairs "overrides whole edges set"
There are also shortcuts for edges:
exporter connectAll "intializes all possible edges".
exporter connectAllNoLoops "intializes all possible edges except loops".
exporter connectAllUndirected "for any 2 nodes only one edge is initialised between them".
exporter connectAllUndirectedNoLoops "Same as previous but without loops"
###Data and properties
To define different properties we use blocks. They will be evaluated for each node to obtain required data.
Remember to initialise the idBlock, the default value is #yourself. Remember that specification says that ID has to be unique.
exporter idBlock: aBlock "block accepts 1 value"
To set a node data values use:
exporter nodeData: #dataName computeAs: aBlock
you can also remove them with:
exporter removeNodeData: #dataName
Each node property has the dedicated getter and setter. If there is no block set (i.e. value is set to nil) that property won't be exported (blocks accepts 1 value).
exporter xBlock: aBlock.
exporter yBlock: aBlock.
exporter sizeBlock: aBlock.
...
Edges data has a similar API as node data, but block have to accept 2 values.
exporter tieData: #dataName computeAs: aBlock.
exporter removeTieData: #dataName
To generate VNA from the exporter either print it on a stream or generate a string:
exporter printOn: aStream.
exporter printString