Add option to inject query code into new code cell

[peller]

moved from jupyter-incubator/declarativewidgets_explorer#65

@jtyberg commented on Aug 22
Using the explorer widget to explore a dataframe is great, but users probably want to DO something with the data that results from the query that the widget executes.

One approach to allow them to do this may be to have the widget generate a code cell below the widget and inject the current incarnation of the Python/R/Scala code that is being used to generate the results the widget is displaying. I like this because it gives the user a way to reproduce the results in the notebook. From there they can tweak the code if desired, save it in a variable, etc.
@lbustelo

@lbustelo commented on Aug 22
Interesting, the only downside is that we've tried to keep the widgets unaware of the language of the kernel. We would need to have the kernel side of the urth-core-dataframe be what generates the code.
@jtyberg

@jtyberg commented on Aug 22
That makes sense. Maybe urth-core-dataframe can provide an API that widgets can use to give them the code without executing it? Reminds me of a dry run. Hey, urth-core-dataframe, what would you do if I gave you these inputs?

[peller]

@jtyberg @lbustelo