Manually checking and setting contexts

This method is very similar to the tContextLoad; however, instead of using tContextLoad to select the file and load and validate the key value pairs, this is performed by custom Java code, within a tJavaRow component, as described in the recipe Setting context variables and globalMap variables using tJava in Chapter 5, Using Java in Talend.

Pros

This method allows the finest grain selection and setting of context variables.

As with the implicit context load and tContextLoad, use of external files is a good practice for managing contexts, because they are less likely to be overwritten during deployment.

This method provides the developer with the ability to validate individual values and kill the job if they are invalid, without having to worry about local context variables.

Cons

The fine grain can also be a weakness. This method does give much more freedom to developers and could become unmanageable.

More manual code is required to manage this method than for managing any of the other methods.

Conclusion

Despite being the most complex method, it is a very good method for managing contexts in a project, so long as the processes are well defined, and the developers are diligent in following the processes.

It provides a high degree of control and is not hampered by the fact that single use context variables may exist within the jobs in the project.