| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @flow |
| 8 | */ |
| 9 | |
| 10 | /** |
| 11 | * Backing FormData is a wrapper around FormData that allows iterating over the |
| 12 | * keys while allowing to evict values from the FormData without affecting the iteration. |
| 13 | * Native FormData.keys() will skip keys if entries with Blob are deleted e.g. |
| 14 | * ```js |
| 15 | * const formData = new FormData(); |
| 16 | * formData.append('a', new Blob()); |
| 17 | * formData.append('b', 2); |
| 18 | * const keys = formData.keys(); |
| 19 | * keys.next().value; // 'a' |
| 20 | * formData.delete('a'); |
| 21 | * keys.next().value; // undefined, but we expect 'b' |
| 22 | * ``` |
| 23 | */ |
| 24 | export opaque type BackingFormData = { |
| 25 | data: FormData, |
| 26 | keyPointer: number, |
| 27 | // Lazily initialized array of keys. We only need this at the moment |
| 28 | // for referenced FormData. |
| 29 | keys: null | Array<string>, |
| 30 | }; |
| 31 | |
| 32 | export function peekBackingEntry(backingStore: BackingFormData): string | void { |
| 33 | let keys = backingStore.keys; |
| 34 | if (keys === null) { |
| 35 | keys = backingStore.keys = Array.from(backingStore.data.keys()); |
| 36 | backingStore.keyPointer = 0; |
| 37 | } |
| 38 | |
| 39 | return keys[backingStore.keyPointer]; |
| 40 | } |
| 41 | |
| 42 | export function advanceBackingEntryIterator( |
| 43 | backingStore: BackingFormData, |
| 44 | ): void { |
| 45 | backingStore.keyPointer++; |
| 46 | } |
| 47 | |
| 48 | export function consumeBackingEntry( |
| 49 | backingStore: BackingFormData, |
| 50 | key: string, |
| 51 | ): void { |
| 52 | backingStore.data.delete(key); |
| 53 | backingStore.keyPointer++; |
| 54 | } |
| 55 | |
| 56 | export function appendBackingEntry( |
| 57 | backingStore: BackingFormData, |
| 58 | key: string, |
| 59 | value: FormDataEntryValue, |
| 60 | ): void { |
| 61 | backingStore.data.append(key, value); |
| 62 | let keys = backingStore.keys; |
| 63 | if (keys === null) { |
| 64 | keys = backingStore.keys = Array.from(backingStore.data.keys()); |
| 65 | backingStore.keyPointer = 0; |
| 66 | } else { |
| 67 | keys.push(key); |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | export function appendBackingFile( |
| 72 | backingStore: BackingFormData, |
| 73 | key: string, |
| 74 | value: Blob, |
| 75 | filename: string, |
| 76 | ): void { |
| 77 | backingStore.data.append(key, value, filename); |
| 78 | let keys = backingStore.keys; |
| 79 | if (keys === null) { |
| 80 | keys = backingStore.keys = Array.from(backingStore.data.keys()); |
| 81 | backingStore.keyPointer = 0; |
| 82 | } else { |
| 83 | keys.push(key); |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | export function getBackingEntry( |
| 88 | backingStore: BackingFormData, |
| 89 | key: string, |
| 90 | ): ?FormDataEntryValue { |
| 91 | return backingStore.data.get(key); |
| 92 | } |
| 93 | |
| 94 | export function getAllBackingEntries( |
| 95 | backingStore: BackingFormData, |
| 96 | key: string, |
| 97 | ): Array<FormDataEntryValue> { |
| 98 | return backingStore.data.getAll(key); |
| 99 | } |
| 100 | |
| 101 | export function createBackingFormData(formData: FormData): BackingFormData { |
| 102 | return { |
| 103 | data: formData, |
| 104 | keyPointer: -1, |
| 105 | keys: null, |
| 106 | }; |
| 107 | } |