Calculate MolWeight and generate SMILES

    /*
    * Calculate Molweight and Smiles
    *
    *
    * Usage:
    * 1. Edit the name of the Structure field
    * 2. Run button script
    *
    * For more details see:
    * https://docs.chemaxon.com/display/jchembase/Utilities
    *
    * @author David Pech <dpech@chemaxon.com>
    */
    import com.im.df.api.*
    import com.im.df.api.support.SelectionDescription
    import com.im.ijc.core.api.util.IJCCoreUtils
    import chemaxon.struc.Molecule
    import chemaxon.util.MolHandler
    
    init = { widget ->
    }
    destroy = { widget ->
    }
    evaluate = { widget ->
        def ety = dataTree.rootVertex.entity // assumes you have reference to the data tree
        def molFld = ety.fields.items.find { it.name == 'Structure' } // find the structure field
        def rs = ety.schema.dataProvider.getDefaultResultSet(dataTree, false, DFEnvironmentRO.DEV_NULL) // find the ResultSet
        def rootVS = rs.getVertexState(dataTree.rootVertex) // obtain the VertexState
    
        List ids = rootVS.getSelectedRowsIds() // get the selected IDs
        if (ids.size == 1) {
            Map rows = rootVS.getData(ids, DFEnvironmentRO.DEV_NULL) // get the data
            Map row = rows[ids[0]] // get the first and only row
            MarvinStructure mol = row[molFld.id] // Get the Structure. Its a com.im.df.api.chem.MarvinStructure instance
            Molecule cxnMol = mol.getNative() // obtain the chemaxon.struc.Molecule instance
    
            // Convert molecule to SMILES
            String molSmiles = cxnMol.toFormat("smiles")
            // Canonical SMILES
            // String molSmiles = cxnMol.toFormat("smiles:u")
            println molSmiles
            // create a MolHandler instance
            // set molecule from SMILES
            // calculate molecular weight
            MolHandler mh = new MolHandler();
            mh.setMolecule(molSmiles);
            println mh.calcMolWeight()
    
        } else {
            println "bad selection"
        }
    }
    on_change = { widget, button ->
    
    }