Add event handling support in ComponentOptions and implement event binding logic in CustomElement

This commit is contained in:
Astrian Zheng 2025-05-14 21:54:17 +10:00
parent 841f02bb38
commit c44c9fc2c0
Signed by: Astrian
SSH Key Fingerprint: SHA256:rVnhx3DAKjujCwWE13aDl7uV6+9U1MvydLkNRXJrBiA

View File

@ -12,6 +12,7 @@ interface ComponentOptions {
onAttributeChanged?: (attrName: string, oldValue: string, newValue: string) => void onAttributeChanged?: (attrName: string, oldValue: string, newValue: string) => void
states?: Record<string, any> states?: Record<string, any>
statesListeners?: { [key: string]: (value: any) => void } statesListeners?: { [key: string]: (value: any) => void }
events?: { [key: string]: (event: Event) => void }
} }
export default (options: ComponentOptions) => { export default (options: ComponentOptions) => {
@ -254,7 +255,31 @@ export default (options: ComponentOptions) => {
} }
}) })
// Can also handle event bindings and other features here // Process @event bindings, such as @click="handleClick"
const eventBindings = Array.from(element.attributes).filter(attr => attr.name.startsWith('@'))
eventBindings.forEach(attr => {
const eventName = attr.name.substring(1) // Remove '@'
const handlerValue = attr.value.trim()
// Remove the attribute, as it is not a standard HTML attribute
element.removeAttribute(attr.name)
// Handle different types of event handlers
if (handlerValue.includes('=>')) {
// Handle arrow function: @click="e => setState('count', count + 1)"
this._setupArrowFunctionHandler(element, eventName, handlerValue)
} else if (handlerValue.includes('(') && handlerValue.includes(')')) {
// Handle function call: @click="increment(5)"
this._setupFunctionCallHandler(element, eventName, handlerValue)
} else if (typeof (this as any)[handlerValue] === 'function') {
// Handle method reference: @click="handleClick"
element.addEventListener(eventName, (this as any)[handlerValue].bind(this))
} else {
// Handle simple expression: @click="count++" or @input="name = $event.target.value"
this._setupExpressionHandler(element, eventName, handlerValue)
}
})
} }
} }
@ -262,6 +287,132 @@ export default (options: ComponentOptions) => {
this._textBindings = textBindings this._textBindings = textBindings
} }
// Handle arrow function
private _setupArrowFunctionHandler(element: Element, eventName: string, handlerValue: string) {
element.addEventListener(eventName, (event: Event) => {
try {
// Arrow function parsing
const arrowIndex = handlerValue.indexOf('=>')
const paramsStr = handlerValue.substring(0, arrowIndex).trim()
let bodyStr = handlerValue.substring(arrowIndex + 2).trim()
// Check if the function body is wrapped in {}
const isMultiline = bodyStr.startsWith('{') && bodyStr.endsWith('}')
// If it is a multiline function body, remove the outer braces
if (isMultiline) {
// Remove the outer braces
bodyStr = bodyStr.substring(1, bodyStr.length - 1)
// Build code for multiline arrow function
const functionCode = `
return function(${paramsStr}) {
${bodyStr}
}
`
// Create context object
const context = this._createHandlerContext(event, element)
// Create and call function
const handlerFn = new Function(functionCode).call(null)
handlerFn.apply(context, [event])
} else {
// Single line arrow function, directly return expression result
const functionCode = `
return function(${paramsStr}) {
return ${bodyStr}
}
`
// Create context object
const context = this._createHandlerContext(event, element)
// Create and call function
const handlerFn = new Function(functionCode).call(null)
handlerFn.apply(context, [event])
}
} catch (err) {
console.error(`Error executing arrow function handler: ${handlerValue}`, err)
}
})
}
// Create handler context
private _createHandlerContext(event: Event, element: Element) {
// Basic context, including state
const context: {
[key: string]: any
$event: Event
$el: Element
this: CustomElementImpl // Provide reference to the component instance
setState: (keyPath: string, value: any) => void
getState: (keyPath: string) => any
} = {
...this._states,
$event: event,
$el: element,
this: this, // Provide reference to the component instance
setState: this.setState.bind(this),
getState: this.getState.bind(this)
}
// Add all methods of the component
Object.getOwnPropertyNames(Object.getPrototypeOf(this)).forEach(name => {
if (typeof (this as any)[name] === 'function' && name !== 'constructor') {
context[name] = (this as any)[name].bind(this)
}
})
return context
}
// Handle function call, such as @click="increment(5)"
private _setupFunctionCallHandler(element: Element, eventName: string, handlerValue: string) {
element.addEventListener(eventName, (event: Event) => {
try {
// Create context object
const context = this._createHandlerContext(event, element)
// Create and execute function call
const fnStr = `
with(this) {
${handlerValue}
}
`
new Function(fnStr).call(context)
} catch (err) {
console.error(`Error executing function call handler: ${handlerValue}`, err)
}
})
}
// Handle simple expression, such as @click="count++" or @input="name = $event.target.value"
private _setupExpressionHandler(element: Element, eventName: string, handlerValue: string) {
element.addEventListener(eventName, (event: Event) => {
try {
// Create context object
const context = this._createHandlerContext(event, element)
// Create expression function
const fnStr = `
with(this) {
${handlerValue}
}
`
// Execute expression
const result = new Function(fnStr).call(context)
// If the expression returns a value, it can be used for two-way binding
return result
} catch (err) {
console.error(`Error executing expression handler: ${handlerValue}`, err)
}
})
}
// Update text node // Update text node
private _updateTextNode(node: Text, expr: string, template: string) { private _updateTextNode(node: Text, expr: string, template: string) {
// Replace all expressions with the current state value // Replace all expressions with the current state value