<SelectField> does not trigger onChange for default value

[sfeidersullivan]

Description

When <SelectField> defaults to the first allowedValue, that value can no longer be selected without changing to another value then changing back.

This is intended behavior for a <select> tag where state is handled by the DOM, but seems like unintended behavior for uniforms where components are controlled by outside state.

Steps to reproduce

1. https://uniforms.tools/playground#?N4IgDgTgpgzlAuIBcIDqUA2BjA9gWygEIQAacCHMGZUAQwFd4cZaA3KZAM1ozjIaYt2AEUy0AnsgCMABhlkAJgEsWAIwxQFXHnxAZaqzMngR6UMmH1YoACxwYFUCNt7mQMLDah5ayEADsoAHcAAgBlJTxLKDDPb1oACmAAHX8Q9JCYJQAvKCQQlLSM4vhxMDzwkyV_AHMSVOLingwcIM0ANR4zGHyAbQByAA8YfpIQ_pGx_rxR8YxZofmAXQaMgF96_zWASlJ3OyCASX8MaqgAUQgKZyRuV34YcX8sAHl_MPpVPCVEW503WiPZ5vTqnBS0eAcP6uDYgeBeAh-OA-fzwJRYEBrIA
2. Select 'xs' from dropdown
3. Click Submit

Affects uniforms-semantic, uniforms-bootstrap, and uniforms-unstyled (any that use <select> tags)

Expected Behavior

If user selects 'xs', the state should be updated

Works fine for uniforms-material since a placeholder is always added as the first item.

Would also be fine if a null or "please select" option was added by default, or if it was clear that the user must pass one in.

[radekmie]

Hi @sfeidersullivan. It works correctly if you enable the placeholder for this field. I have to think about how to make it consistent between themes.

[radekmie]

Now it seems to be consistent and fully usable. All fields without value start with placeholders, and only optional ones are allowed to set it back (which clears the value).