Renaming and Copying Attributes
Renaming and - to a lesser extent - copying attributes are also key attribute functions within FME.When an attribute is renamed it ceases to exist under its prior name;when it is copied it exists both in its new and old names.
The transformers capable of renaming an attribute are:
Transformer | Capability |
---|---|
AttributeCopier | Copy |
AttributeCreator | Copy |
AttributeManager | Copy and Rename |
AttributeRenamer | Rename |
Renaming
The fundamental purpose of this transformer is to manually enter a new name for a selected attribute.The old attribute is removed and replaced with the newly named one.
Here the user is renaming a number of fields by entering a different name for the Output Attribute.The Action is automatically set to Rename.Notice that the user is also entering a new constant value for the PSTLCITY/PostalCity attribute.
This type of behaviour is obviously of use when the Reader schema ('what we have') needs to be renamed to match the Writer schema ('what we want').
TIP |
Although you can manually type a new attribute name into the Output Attribute field,if the transformer is connected to the correct Writer feature type,its attribute names will be automatically available to select from: |
Copying
Depending on the transformer,copying an attribute can be one of two styles.
Here the AttributeCopier consists of selecting the existing attribute and entering a new name for it.Again,when connected to a Writer feature type,its schema is available to select from.
TIP |
You can (as above) enter a constant attribute value in the AttributeCopier,but in reality it's hardly a copy operation in that case;it's more an attribute creation task. |
Note how both PSTLCITY and PostalCity exist on the output of the transformer,proving that it is copying the attribute rather than renaming it.
For other transformers,the setup style is reversed: a new attribute is created and given the value of an existing attribute:
In this AttributeManager transformer the user creates a new attribute (PostalCity) and assigns it the value from another (PSTLCITY).In effect they have made a copy of the original attribute.