MyGo v0.5.5 returns ui.Element as a checked value handle instead of a
pointer. Migrated with `mygo migrate-ui`, then fixed what the codemod
leaves to review:
- Element nil checks become .Valid(); absent elements are ui.Element{}.
- Input handlers and paint callbacks run outside the build pass, where
elements expire and Context methods are inert: read IsDisabled into a
local during the build, keep a ui.Handle for Focus, use c.Services()
for clipboard access, create ui.Local state during the build.
- Add core.AutoFocus: v0.5.5 records an overlay's opener after its
content builds, so same-frame autofocus lost focus restore on close.
It focuses one frame later; cascader rows defer their focus likewise.
- core.OverlayLayer identifies build passes by the root element, not
c.Now(), which repeats across passes and under the Tester clock.
- Context menus survive the opening press counted as PressedOutside;
split button tooltip no longer reorders its open menu; disabled
menubar rows pass presses to the panel; Form defers blur-started
async checks so the growing message no longer moves Submit away
from the release; Combobox drops its disabled copy now that MyGo
blocks typing under a disabled wrapper (canary flipped to a guard).
- The Tester clock is virtual: tests use Advance/Now instead of
time.Sleep/time.Now and read element state inside the view. The web
mirror advances the clock to wall time before each frame and input.
- AGENTS.md and docs describe the value Element API and the new pin.
Snapshot goldens are darwin-only and were not re-verified here.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
3.2 KiB
3.2 KiB
041 Form
表单。
用途
组合多个字段:注册字段、同步与调用方提供的异步校验、提交与重置、提交中防重入、提交失败时定位第一个错误字段。Form 不保存业务模型,不调用远程接口,也不做持久化;值始终由应用持有。
最小示例
var state input.FormState
name := ""
view := func(c *ui.Context) {
core.Use(c, core.Settings{})
res := input.Form(c, &state, input.FormOptions{}, func(f *input.FormScope) {
input.FormItem(c, f, "name", &name, input.FormItemOptions[string]{Label: "Name", Required: true}, func() ui.Element {
return input.InputGroup(c, &name, input.InputGroupOptions{Invalid: state.Error("name") != ""}).Input
})
})
if res.Submitted() {
state.EndSubmit("") // after saving name
}
}
ui.Render(view, 400, 300, 1)
参数
| 字段 | 类型 | 默认值 | 含义 |
|---|---|---|---|
FormOptions.Horizontal |
bool |
false | 标签放在控件左侧一列,右对齐。 |
FormOptions.SubmitLabel |
string |
内置“Submit/提交” | 提交按钮文字。 |
FormOptions.ResetLabel |
string |
内置“Reset/重置” | 重置按钮文字。 |
FormItemOptions[T].Label |
string |
必填 | 字段标签;空值 panic。 |
FormItemOptions[T].Required |
bool |
false | 标记必填;零值、空字符串、空切片或空映射视为缺失。 |
FormItemOptions[T].Description |
string |
"" | 说明文字;异步校验进行中显示“Checking…”。 |
FormItemOptions[T].Initial |
T |
零值 | 重置时写回的初始值。 |
FormItemOptions[T].Validate |
func(T) string |
nil | 同步校验,返回错误文字或 "";跨字段规则在此读取其他值。 |
FormItemOptions[T].Async |
func(v T, version uint64) |
nil | 启动异步校验;完成后在界面线程调用 FormState.Resolve(name, version, msg)。 |
状态
默认;字段错误(触碰后或首次提交后才显示);异步校验中(说明显示 Checking…);提交中(提交按钮显示加载并阻止重复提交,重置禁用);提交失败(表单级错误显示在按钮上方,保留全部值)。
事件
FormParts.Submitted():全部校验通过的一次提交,处理完毕后调用 FormState.EndSubmit(err)。FormParts.Reset():已恢复初始值并清除校验与提交状态。FormState.Submit() 可在 Enter 等处请求提交。FormState.Error(name) 返回当前应显示的错误,用于给控件设置 Invalid。
键盘操作
Tab / Shift+Tab 在字段间移动,离开字段即校验。提交失败后焦点移到第一个错误字段并滚动到可见处,同时向屏幕阅读器播报。点击标签聚焦控件。
限制
- 控件由调用方构建,
FormItem的 control 回调必须返回可获取焦点的元素,用于错误定位。 - 校验在失焦与提交时触发;已触碰字段在值变化时重新同步校验,异步校验只在下一次失焦或提交时重跑。
- 异步结果以版本号对齐:值变化后旧版本的
Resolve返回 false 并被丢弃。FormState的方法只能在界面线程调用,后台任务需经Window.Update回到界面线程。 - 必填标记“*”只作视觉显示,辅助技术通过说明“必填”获知。