Remove reveal_timeout can not be larger or equal to settlement_timout message

[err508]

Problem Definition

When opening a channel a user is given the option to choose the settle timeout. The UI denotes: The smallest allowed value is 1 and displays reveal_timeout can not be larger or equal to settlement_timeout if a to small settlement timeout is chosen.
I'd suggest to remove the error message here and display the minimum Settle Timeout as constrained by the reveal_timeout in the channel opening view.

[kelsos]

@err508 the smallest allowed value is 1 is the hint message displayed below the input field above, which is the balance field. Each error message appears on the bottom of an input field and has a red colored text.

[err508]

@kelsos The Settle Timeout must also be larger than the reveal_timeout of the Settle Timeout of a particular token as required here. This token specific information is available already in the client.

[kelsos]

@err508 Thanks, I will add an extra validation to the field.

[kelsos]

@err508 I am having trouble finding where reveal_timeout is actually exposed in the REST api.
The /tokens returns an array of token contract addresses. Any meaningful information (balance, name etc) is then queried directly from the ERC20 token via web3.js. The /connections api doesn't seem to contain any information about reveal_timeout either.

The message reveal_timeout can not be larger or equal to settlement_timeout seems to originate from the REST api.

The only place I could find reveal_timeout information was in the list of channels.

[andrevmatos]

@kelsos reveal_timeout is channel-specific, not token-specific (afaict), and comes in channels endpoints

[kelsos]

@andrevmatos Yes but if I need to validate the settle_timeout against the reveal_timeout on the channel open dialog I can't use the information from the channels endpoint can I?

[andrevmatos]

No, you can't. reveal_timeout is also "tweakable" by clients, but that isn't exposed. Therefore, we could also expose the default value in config.json, as per #2393 (comment)

[kelsos]

@andrevmatos If we can also expose it along with the other information it would be great 👍

[err508]

If the reveal timeout is tweakable, we only have a lower bound for the settle_timeout input given by the token's Settle_Timeout no? As of here the initiator of a mediated transfer chooses the reveal_timeout and the client only has to check that it is smaller than the Settle timeout for its mediating channel.
We could display an explanation at this point, that a larger settlement timeout is correlated to a higher degree of security (in case of offline time) and a larger amount of mediated transfers/mediation fees, but in turn the tokens are locked for a prolonged time if the user might want to move them away from a channel.

[andrevmatos]

Yes, reveal_timeout is a lower bound to settle_timeout, and both are tweakables, although not exposed in the webUI nor the docs. I'm working on a PR to expose the default values in config.json, and the webui will be able to use this lower bounday.

[andrevmatos]

Ok, there's a problem. The reveal_timeout is actually exposed through the API (both rest and python) but isn't taken into account when opening the channel (#2529). I did PR #2531 to expose the values of these variables through webUI's config.json.
@kelsos , please, make a follow up PR over it to use these values throughout the webui:

• Default settle_timeout in the open dialog populated from the config
• Minimum settle_timeout value is reveal_timeout * 2
  

  raiden/raiden/app.py

  Line 94 in d989738

  config['settle_timeout'] < config['reveal_timeout'] * 2