Json Instruments V1 - WIP

[jacobpenny]

WIP PR to facilitate conversation

[jacobpenny]

@driusan Addressed your comments. Still need to fix one test and do javascript linting though.

[jacobpenny]

The React components are in need of some optimization. For most instruments it isn't an issue but while testing one of our instruments (which contains 704 elements) we noticed significant slow-downs, mostly when editing a text box. As far as I can tell there are two causes:

1. Wasteful re-rendering
2. Evaluation of RequireResponse, DisplayIf, and Score Fields whenever there is user input.

Here are some ideas for optimizing:

1. Use react-addons-perf's printWasted method to see which elements are being needlessly re-rendered. (https://facebook.github.io/react/docs/perf.html#printwasted). Overriding the lifecycle function shouldComponentUpdate can avoid these wasteful re-renders for these elements.

2. The two functions annotateElements and filterElements, called here and here, could be combined to reduce the number of iterations through the elements.

3. Avoid evaluating RequireResponse until the user tries to submit.

4. For text input fields, instead of triggering an update onUserInput (i.e. every key stroke), only trigger the update onBlur. This is tricky because the text components would need to track their own state (i.e. no longer be controlled inputs).

[driusan]

@ZainVirani is working on splitting this up, but I'm adding the Block tag and leaving this open so we don't forget about it.

[xlecours]

This work is referenced in Redmine ticket #13780