Support readOnly and writeOnly attribute of json-schema

[domhaas]

Scope of required: per design system/widget

• DS-Material
• DS-Bootstrap
• DS-Blueprint

Summary

We should support the "readOnly" Attribute of the json schema to allow disabling of controls:
https://github.com/json-schema-org/json-schema-spec/blob/master/meta/meta-data.json#L24-L27

Examples

My current implementation in ds-blueprint:

As readOnly means you cannot modify an input, I make use of the "disabled" attribute on the blueprintjs-components:

const readOnly = schema.get('readOnly') === true
(...)
<RendererComponent
  (...)
  disabled={readOnly}
/>

Example-Implementation

Motivation

[elbakerino]

Oh thats a good point!

I got a few ideas/thoughts here:

• readOnly restricts that the a value can not be changed
  • how does this influence default?
  • text fields need to support disabled, but what for e.g. GenericList
  • should the store be readOnly aware? so it simply is impossible to change those values?
    • but this could be a really tricky thing with allOf and default
  • should it be possible to render something completely different for read only?
    • e.g. a table would make sense for a read only GenericList/SimpleList
• writeOnly restricts that the widget does not display it's value, but can change it
  • should the widget get the value (the changed value is needed no matter how) or only something like isNotEmpty
  • use case password change: the widget will never receive the value, but it should know there is already an active password
  • how should it be validated when the actual value is never available in the client (e.g. password)

[domhaas]

Oh thats a good point!

I got a few ideas/thoughts here:

* `readOnly` restricts that the a value can not be changed
  
  * how does this influence `default`?
  * text fields need to support `disabled`, but what for e.g. `GenericList`
  * should the store be `readOnly` aware? so it simply is impossible to change those values?
    
    * but this could be a really tricky thing with `allOf` and `default`
  * should it be possible to render something completely different for read only?
    
    * e.g. a table would make sense for a read only `GenericList`/`SimpleList`

* `writeOnly` restricts that the widget does not display it's value, but can change it
  
  * should the widget get the value (the changed value is needed no matter how) or only something like `isNotEmpty`
  * use case password change: the widget will never receive the value, but it should know there is already an active password
  * how should it be validated when the actual value is never available in the client (e.g. password)

Good points. I think we should check out some comparable libraries how they implemented those two attributes.
Also I'm going to get some more information on those questions at the json-schema-repo.

[elbakerino]

react-jsonschema-form:

• AltDateWidget in this lines when readonly the setters are disabled
• ArrayField here disabled is used for input buttons when readonly
• TextWidget disabled on textfield, no onChange checks

Not so many support readonly, in a few i didn't found the actual implementation.

writeOnly was in no other project repository

[domhaas]

I've checked several Libs in different languages. "writeOnly" is indeed completely ignored.
"readonly" has quiet always the same scheme: Disable the main-controls and their children and show it to the user.

My proposition on controls with readOnly:

• stop interaction
• show it to the user (gray out)

I don't think we need to go further and build also checks inside the store that really nobody can change any readOnly-Value.
If somebody wants to hack values in the frontend, he simply can do it, whatever we implement to avoid that.

[domhaas]

@elbakerino Update to writeOnly-Attribute:
Like mentioned here writeOnly means really that you cannot read what you write.
The main use-case would be to make a password-input not readable (****).

I'm going to implement that in ds-bootstrap.

[elbakerino]

readOnly is implemented in ui-schema/ds-material in 0.2.1.

For SimpleList/GenericList only for the array level, if also the values must be read only, the keyword must be set on all.

Doesn't do anything for object.

[elbakerino]

Further optimized readOnly with #173 for ds-material selections / options.

[elbakerino]

New readOnly options using read-or-write, see #78 for further details,

writeOnly is only good in UI for special use cases, it is best to add own widgets/plugins/validators - as the "what and how" is too complex to abstract by a standard in this library.