Created
October 30, 2019 02:50
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// this is @Lukeed's 'sublet' with some small changes to allow for automatic dependency tracking as well as | |
// explicit registering of change effects | |
// prob should use a weakMap for these | |
const reactionsMap = {}; | |
const contextMap = {}; | |
let ctx; | |
export const setContext = id => { | |
ctx = id; | |
} | |
export const clearContext = el => { | |
//console.log('mapping', ctx, ' to ', el); | |
contextMap[ctx] = el; | |
ctx = null; | |
return el; | |
}; | |
function handler(key, shim, obj) { | |
Object.defineProperty(shim, key, { | |
enumerable: true, | |
get: function() { | |
if (contextMap[ctx] === undefined) return obj[key]; | |
if (!reactionsMap[key]) { | |
reactionsMap[key] = [contextMap[ctx]]; | |
} | |
const hasComponent = reactionsMap[key].find(c => c._id === contextMap[ctx]._id); | |
if (!hasComponent) { | |
reactionsMap[key].push(contextMap[ctx]); | |
} | |
return obj[key]; | |
}, | |
set: function(v) { | |
console.log('set'); | |
if (obj[key] !== v) { | |
obj[key] = v; | |
reactionsMap[key].forEach(c => { | |
if (c.update !== undefined) c.update(); | |
}); | |
} | |
return v; | |
}, | |
}); | |
} | |
export function Store(obj) { | |
var k, shim={}; | |
if (Array.isArray(obj)) { | |
shim = obj; | |
} else { | |
for (k in obj) { | |
handler(k, shim, obj); | |
} | |
} | |
return shim; | |
} |
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