| 1 | import { isAction, autorun, action, isObservableArray, runInAction } from "mobx";
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| 2 | /**
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| 3 | * `chunkProcessor` takes an observable array, observes it and calls `processor`
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| 4 | * once for a chunk of items added to the observable array, optionally deboucing the action.
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| 5 | * The maximum chunk size can be limited by number.
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| 6 | * This allows both, splitting larger into smaller chunks or (when debounced) combining smaller
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| 7 | * chunks and/or single items into reasonable chunks of work.
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| 8 | *
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| 9 | * @example
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| 10 | * const trackedActions = observable([])
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| 11 | * const stop = chunkProcessor(trackedActions, chunkOfMax10Items => {
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| 12 | * sendTrackedActionsToServer(chunkOfMax10Items);
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| 13 | * }, 100, 10)
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| 14 | *
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| 15 | * // usage:
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| 16 | * trackedActions.push("scrolled")
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| 17 | * trackedActions.push("hoveredButton")
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| 18 | * // when both pushes happen within 100ms, there will be only one call to server
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| 19 | *
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| 20 | * @param {T[]} observableArray observable array instance to track
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| 21 | * @param {(item: T[]) => void} processor action to call per item
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| 22 | * @param {number} [debounce=0] optional debounce time in ms. With debounce 0 the processor will run synchronously
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| 23 | * @param {number} [maxChunkSize=0] optionally do not call on full array but smaller chunks. With 0 it will process the full array.
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| 24 | * @returns {IDisposer} stops the processor
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| 25 | */
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| 26 | export function chunkProcessor(observableArray, processor, debounce, maxChunkSize) {
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| 27 | if (debounce === void 0) { debounce = 0; }
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| 28 | if (maxChunkSize === void 0) { maxChunkSize = 0; }
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| 29 | if (!isObservableArray(observableArray))
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| 30 | throw new Error("Expected observable array as first argument");
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| 31 | if (!isAction(processor))
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| 32 | processor = action("chunkProcessor", processor);
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| 33 | var runner = function () {
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| 34 | var _loop_1 = function () {
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| 35 | var chunkSize = maxChunkSize === 0
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| 36 | ? observableArray.length
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| 37 | : Math.min(observableArray.length, maxChunkSize);
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| 38 | // construct a final set
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| 39 | var items = observableArray.slice(0, chunkSize);
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| 40 | // clear the slice for next iteration
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| 41 | runInAction(function () { return observableArray.splice(0, chunkSize); });
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| 42 | // fire processor
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| 43 | processor(items);
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| 44 | };
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| 45 | while (observableArray.length > 0) {
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| 46 | _loop_1();
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| 47 | }
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| 48 | };
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| 49 | if (debounce > 0)
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| 50 | return autorun(runner, { delay: debounce });
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| 51 | else
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| 52 | return autorun(runner);
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| 53 | }
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