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| 1 'use strict'; |
| 2 |
| 3 // Copies the information out of a DataTransfer instance. This is necessary |
| 4 // because dataTransfer instances get neutered after their event handlers exit. |
| 5 // |
| 6 // Returns a Promise that resolves to an object which mirrors the DataTransfer's |
| 7 // files, items, and types attributes, as well as the return values of the |
| 8 // getData function. The contents of files and file items are read using |
| 9 // FileReader. |
| 10 const copyDataTransfer = dataTransfer => { |
| 11 const types = dataTransfer.types.slice(); |
| 12 const data = {}; |
| 13 for (let type of types) { |
| 14 try { |
| 15 data[type] = dataTransfer.getData(type); |
| 16 } catch(e) { // Catches SecurityError exceptions. |
| 17 data[type] = e; |
| 18 } |
| 19 } |
| 20 |
| 21 const readerPromises = []; |
| 22 |
| 23 const files = []; |
| 24 for (let file of Array.from(dataTransfer.files || [])) { |
| 25 const fileData = { file: file }; |
| 26 files.push(fileData); |
| 27 |
| 28 readerPromises.push(new Promise((resolve, reject) => { |
| 29 const reader = new FileReader(); |
| 30 reader.onloadend = event => { |
| 31 if (event.target.error) |
| 32 fileData.error = event.target.error; |
| 33 else |
| 34 fileData.data = event.target.result; |
| 35 resolve(); |
| 36 }; |
| 37 reader.readAsText(file); |
| 38 }).catch(e => fileData.error = e)); |
| 39 } |
| 40 |
| 41 const items = []; |
| 42 for (let item of Array.from(dataTransfer.items || [])) { |
| 43 const itemData = { kind: item.kind, type: item.type }; |
| 44 items.push(itemData); |
| 45 |
| 46 readerPromises.push(new Promise((resolve, reject) => { |
| 47 if (itemData.kind === 'file') { |
| 48 itemData.file = item.getAsFile(); |
| 49 if (itemData.file === null) { // DataTransfer is in protected mode. |
| 50 resolve(); |
| 51 return; |
| 52 } |
| 53 |
| 54 const reader = new FileReader(); |
| 55 reader.onloadend = event => { |
| 56 if (event.target.error) |
| 57 itemData.data = event.target.error; |
| 58 else |
| 59 itemData.data = event.target.result; |
| 60 resolve(); |
| 61 }; |
| 62 reader.readAsText(itemData.file); |
| 63 } |
| 64 }).catch(e => itemData.error = e)); |
| 65 } |
| 66 |
| 67 return Promise.all(readerPromises).then(() => { |
| 68 return { data, files, items, types }; |
| 69 }); |
| 70 }; |
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