What is the "color" option default?

[stockiNail]

I have a doubt about what's the default of color option.

Having a look to the code and the overrides of the controller, I see:

chartjs-chart-sankey/src/controller.js

Line 370 in 95ed08b

color: () => '#efefef',

It's defined as scriptable options but it will be never called.

In fact, to set the fillStyle is using doing as following:

chartjs-chart-sankey/src/controller.js

Line 208 in 95ed08b

ctx.fillStyle = dataset.color || 'black';

where it seems that if color is missing, it uses black.

Furthermore, it's weird why is using dataset.color instead of me.options.color.
Doing some tests, using me.options.color, the callback to set the option seems to be invoked (but not the callback set in the overrides).

I don't know if it's an issue but I would like to use me.options.color. Make sense or am I wrong?

[kurkle]

I think you are correct, the dataset is not a "resolver", so it will not call the function. I think me.options.color is correct and should fallback to the dataset overrides, if the options is not defined. If it does not, then that is another issue to look at.

[stockiNail]

Very good, I'm gonna submit PR (but not now, sorry...)

[stockiNail]

@kurkle I did some tests.

I changed the following code from

chartjs-chart-sankey/src/controller.js

Line 216 in b32c942

ctx.fillStyle = dataset.color || 'black';

to

ctx.fillStyle = me.options.color;

and using the basic sample to check the result.

The ctx.fillStyle is set to #666, the default color option but is NOT triggering the the scriptable option set int the overrides:

chartjs-chart-sankey/src/controller.js

Lines 378 to 387 in b32c942

	SankeyController.overrides = {
	interaction: {
	mode: 'nearest',
	intersect: true
	},
	datasets: {
	color: () => '#efefef',
	clip: false,
	parsing: true
	},

Then, having a look to the fallback of CHARTJS at dataset level, you can see:

Dataset level options

dataset.type defaults to config.type, if not specified.

• dataset
• options.datasets[dataset.type]
• options
• overrides[config.type].datasets[dataset.type]
• defaults.datasets[dataset.type]
• defaults

and then the overrides are checked after the options, where the color option always exists because is the color for the chart for all other chart elements (axis, legend, title, and so on).

Therefore, in my opinion, new PR should:

1. remove line 384 of controller.js color: () => '#efefef', , because never used
2. apply ctx.fillStyle = me.options.color;

But I have a doubt: where should the dataset options default be set in the controller? SankeyController.defaults?

[stockiNail]

Another doubt. All options related to the nodes, leveraging on me.options.* are becoming to scriptable.
Nevertheless the context which is passed to the function is always a dataset context and doesn't allow to set different styles to each node but a option is used for all nodes. This could be the reason why the dataset instance is used to retrieve the options instead of the options of the controller, because at the end of the day the options can not be set for each node.
About color, you could want to have different label color for different nodes and that's not possible.

Having a look to the code, in order to activate different style for each node, the scriptable options for nodes need to have a specific context, where the node is part of the context otherwise is not possible to apply a consistent logic.

What do you think? Make sense?

[kurkle]

Been a while, but I think it makes sense. Somewhat related note, I think the nodes need to be made elements to let users interact with them.

[RishikeshB]

is there is any option to give background for label has shown in test sample from repo: