Interface GrelExpr

    • Method Detail

      • evaluate

        Object evaluate​(Properties bindings)
        Returns the value of the expression in a given context.
        Parameters:
        bindings - the evaluation context, mapping variable names to their values
        Returns:
        the result of the evaluation of the expression
      • toString

        String toString()
        For GREL expressions, toString should return the source code of the expression, or a source code for an equivalent expression. (without the "grel:" prefix).
        Overrides:
        toString in class Object
      • isLocal

        boolean isLocal()
        Returns:
        true when the expression can be evaluated purely based on the local context (see Evaluable).
      • getColumnDependencies

        Set<String> getColumnDependencies​(String baseColumn)
        Returns the names of the columns this expression depends on.
        Parameters:
        baseColumn - the name of the column this expression is based on (null if none)
        Returns:
        null if the columns could not be isolated: in this case, the expression might depend on all columns in the project.
      • renameColumnDependencies

        GrelExpr renameColumnDependencies​(Map<String,​String> substitutions)
        Translates this expression by simultaneously substituting column names as the supplied map specifies.

        This is only possible if the extraction of column dependencies with getColumnDependencies(String) succeeds (return a non-null value).

        Parameters:
        substitutions - a map specifying new names for some columns. If a column name is not present in the map, it is assumed that the column is not renamed.
        Returns:
        a new expression with updated column names.