tFileOutputGML is a Talend Open Studio component writes a file in Graph Modeling Language version 1, compatible with Gephi, Pajek and lots more software for network analysis and social network analysis especially. It’s not a simple file output component, as it supports both nodes and edge writing, talend-to-gml types conversions and some unique features of graph files, like labels and weights. However, it doesn’t support data structures yet, as same as graphics and icons directives. It still doesn’t validate the graph (ie. edges referring to non-existent or invalid nodes), but this feature is under heavy development.
How to use the component
This component support one to two input flow connections. The first is mandatory and it contains nodes definition. You must select the input columns that feed node id and node label respectively. The second connection is optional, as (technically speaking) graph are complete, even useless, without edges definition. If you need to adds edge definition in output file, then you must provide a lookup connection describing them, specifying at least source and target id columns. If available, you can activate weight and edge label columns, too. The screenshot on page opening should give you an idea on how this double-connection input element can be used in a real task.
The output schema parameter (the first from upside) let you choose which columns to map as node attributes in output file. Columns are not propagated by default so you can choose which ones to include rather than to drop. Strings are automatically quoted, while lists serialized.
Finally, in advanced parameters you can set some file properties, like character encoding, row separator, graph name and so on.
Aside writing to a .gml file, the component can feed an optional outgoing main flow connection that propagates the whole set of node attributes that makes the output schema, as set in schema parameter. Please note that no content from lookup connection (edge details) is propagated in this outgoing connection.