40 lines
919 B
JavaScript
40 lines
919 B
JavaScript
module.exports = {
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dispatch,
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dispatcher,
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setDispatch
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}
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const dispatchers = {}
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let _dispatch = function () {}
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function setDispatch (dispatch) {
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_dispatch = dispatch
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}
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function dispatch (...args) {
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_dispatch(...args)
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}
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// Most DOM event handlers are trivial functions like `() => dispatch(<args>)`.
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// For these, `dispatcher(<args>)` is preferred because it memoizes the handler
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// function. This prevents React from updating the listener functions on
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// each update().
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function dispatcher (...args) {
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const str = JSON.stringify(args)
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let handler = dispatchers[str]
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if (!handler) {
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handler = dispatchers[str] = function (e) {
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// Do not propagate click to elements below the button
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e.stopPropagation()
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if (e.currentTarget.classList.contains('disabled')) {
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// Ignore clicks on disabled elements
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return
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}
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dispatch(...args)
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}
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}
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return handler
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}
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