|A Context Map is a type of Admin Item.|
A Context Map allows the differences between the codes used in a Source Context and those in a Target Context to be managed.
The primary tool is the Link editor. This allows Links to be created in the Context Map that record how each Source EDT is associated with a corresponding EDT in the Target Context. Usually each Source EDT is linked to just one target EDT each. Some however may need to be linked to more than one Target EDT. The Link editor allows drag and drop linking of EDTs in the user's normal browser window.
In the diagram above 'Hair Colour' has been linked to 'FEATURE_TYPE'. These EDTs point to different Code Lists so the codes will need to be mapped using a Code Map. 'Sex' however has been linked to 'GENDER_TYPE' and both have been defined against the same Code List (Sex v2) so there is no Code Mapping to be done. Each 'Sex' code is understood as a 'GENDER_TYPE' code directly. 'Vehicle Model' has been linked to both 'CAR_MODEL_TYPE' and 'HGV_MODEL_TYPE' so two Code Maps will be required to handle the mappings of the two sections of Models v1.2.3.
So a Context Map contains two types of content:
- a set of Links between Source EDTs and Target EDTs
- a collection of Code Maps that detail how the source and target codes for each Link are mapped
Context Maps usually link two different Contexts. The Source Context is often a local application system that needs to pass information to a target Context that is a national aggregation of some sort.
There are other uses for Context Maps however:
- A Context Map that links an application Context to a data standard Context can be used to quantify how 'conformant' the application system is with a particular Data Standard. If all the application's EDTs link directly to the data standard EDTs the application is 100% conformant with the data standard. If some require maps it is less so.
- A Context Map that links a Context to itself can be useful to manage a group of inter-relationships between data types e.g. the associations between CJS Offence Codes, Home Office statistics codes and DVLA codes.
Each Context Map's template has the following properties:
|Live Start Date||This is the date when the Context Map became or is due to become 'Live'. It can be used by the Steward Team to help control the synchronized introduction of Context Maps across a group of related applications because it signifies when a particular application should switch from using an earlier version of a Context Map to a later one.|
How To guides for Context Maps are here
Context Map Business Rules are here