## extraNode

extraNode — add further characteristics to the nodes.

## Synopsis

    void                extraNodeAdd_label                  (VisuData *data);
    void                extraNodeSet_label                  (VisuData *data,
                                                             unsigned int nodeId,
                                                             const gchar *label);
    const gchar*        extraNodeGet_label                  (VisuData *data,
                                                             VisuNode *node);

## Description

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## Details

### extraNodeAdd_label ()

    void                extraNodeAdd_label                  (VisuData *data);

Add the possibility to store labels for nodes.

`data` : | a VisuData object.

### extraNodeSet_label ()

    void                extraNodeSet_label                  (VisuData *data,
                                                             unsigned int nodeId,
                                                             const gchar *label);

Set a `label` to the node `nodeId`.

`data` : | a VisuData object.
`nodeId` : | the id of a node.
`label` : | the label to set (will be copied).

### extraNodeGet_label ()

    const gchar*        extraNodeGet_label                  (VisuData *data,
                                                             VisuNode *node);

Retrieve the label of `node`. If `node` has no label, NULL is returned.

`data` : | a VisuData object.
`node` : | a given node
Returns : | a label, private value, do not freed.