23 lines
686 B
TypeScript
23 lines
686 B
TypeScript
import { NodeTransform } from '../transform'
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import { findDir } from '../utils'
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import { ElementNode, ForNode, IfNode, NodeTypes } from '../ast'
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import { SET_BLOCK_TRACKING } from '../runtimeHelpers'
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const seen = new WeakSet()
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export const transformOnce: NodeTransform = (node, context) => {
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if (node.type === NodeTypes.ELEMENT && findDir(node, 'once', true)) {
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if (seen.has(node)) {
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return
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}
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seen.add(node)
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context.helper(SET_BLOCK_TRACKING)
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return () => {
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const cur = context.currentNode as ElementNode | IfNode | ForNode
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if (cur.codegenNode) {
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cur.codegenNode = context.cache(cur.codegenNode, true /* isVNode */)
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}
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}
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}
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}
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