Class Chainr.ContextualTransformAdapter

  • All Implemented Interfaces:
    ContextualTransform, JoltTransform
    Enclosing class:
    Chainr

    private static class Chainr.ContextualTransformAdapter
    extends java.lang.Object
    implements ContextualTransform
    Adapt "normal" Transforms to look like ContextualTransforms, so that Chainr can just maintain a single list of "JoltTransforms" to run.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.Object transform​(java.lang.Object input, java.util.Map<java.lang.String,​java.lang.Object> context)
      Execute a transform on some input JSON with optionally provided "context" and return the result.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • transform

        private final Transform transform
    • Constructor Detail

      • ContextualTransformAdapter

        private ContextualTransformAdapter​(Transform transform)
    • Method Detail

      • transform

        public java.lang.Object transform​(java.lang.Object input,
                                          java.util.Map<java.lang.String,​java.lang.Object> context)
        Description copied from interface: ContextualTransform
        Execute a transform on some input JSON with optionally provided "context" and return the result. The "context" allows transforms to tweak their behavior based upon criteria outside of the input JSON object. The canonical example for the need to have Transforms consider "context" is a Transform that creates urls based upon input data. Should it generate "http" or "https" urls? Most likely the input JSON data does not provide any guidance. This is what the "context" is for. It allows the consumer of the Transform to specialize itself based on data outside the scope of the input JSON. Without the "context" notion you would instead create a HttpUrlTransform and a HttpsUrlTransform. This creates problems when you want to used them as part of a larger Chainr Transform, as you would need to create two Chainrs that are almost the same. The number of Chainrs needed grows exponentially as you add other context sensitive transforms.
        Specified by:
        transform in interface ContextualTransform
        Parameters:
        input - the JSON object to transform in plain vanilla Jackson Map style
        context - information outside of the input JSON that needs to be taken into account when doing the transform
        Returns:
        the results of the transformation