IDE with defaults

[rmarren1]

Adds default arguments to build-time generated python files.

In this PR:

• None replaces the javascript null
• Component._NO_DEFAULT_ARG is given for properties with no default argument
• The python True, False are in place of the javascript true, false
• Javascript objects are converted to python dictionaries

Example:

class Graph(Component):
    """docstring'"""
    @_explicitize_args
    def __init__(self, id=Component._NO_DEFAULT_ARG, clickData=None, hoverData=None, clear_on_unhover=False, selectedData=None, relayoutData=None, figure={'data': [], 'layout': {}}, style=Component._NO_DEFAULT_ARG, className=Component._NO_DEFAULT_ARG, animate=False, animation_options={'frame': {'redraw': False}, 'transition': {'duration': 750, 'ease': 'cubic-in-out'}}, config={'staticPlot': False, 'editable': False, 'edits': {'annotationPosition': False, 'annotationTail': False, 'annotationText': False, 'axisTitleText': False, 'colorbarPosition': False, 'colorbarTitleText': False, 'legendPosition': False, 'legendText': False, 'shapePosition': False, 'titleText': False}, 'autosizable': False, 'queueLength': 0, 'fillFrame': False, 'frameMargins': 0, 'scrollZoom': False, 'doubleClick': 'reset+autosize', 'showTips': True, 'showAxisDragHandles': True, 'showAxisRangeEntryBoxes': True, 'showLink': False, 'sendData': True, 'linkText': 'Edit chart', 'showSources': False, 'displayModeBar': 'hover', 'modeBarButtonsToRemove': [], 'modeBarButtonsToAdd': [], 'modeBarButtons': False, 'displaylogo': True, 'plotGlPixelRatio': 2, 'topojsonURL': 'https://cdn.plot.ly/', 'mapboxAccessToken': None}, **kwargs):
        

see also:
plotly/dash-core-components#234
plotly/dash-html-components#51

[chriddyp]

What was the syntax that we ended up agreeing on last Friday? Was it Component.Undefined and Component.Required?

[rmarren1]

Yes, rather than just None for everything. I ended up capitalizing (Component.REQUIRED). I have included those changes in #276, I am reserving this PR for the case when we are actually setting the default properties on the Python objects.

[alexcjohnson]

These ideas have been incorporated into other completed or in-progress PRs - closing.