use-scan-detection - npm Package Compare versions

Comparing version 0.1.3 to 0.1.4

package.json

 {
   "name": "use-scan-detection",
-  "version": "0.1.3",
+  "version": "0.1.4",
   "description": "A react hook for detecting barcode scanner input.",
@@ -5,0 +5,0 @@ "main": "dist/index.js",

README.md

@@ -25,5 +25,6 @@ # useScanDetection
 |   ---         |   ---         |
-|   waitTime    |   Maximum time between characters in milliseconds. Used to determine if input is from keyboard or a scanner. Defaults to `50`. |
+|   averageWaitTime    | Average time between characters in milliseconds. Used to determine if input is from keyboard or a scanner. Defaults to `50`. |
+| timeToEvaluate    | Time to evaluate the buffer after each character. |
 | startCharacter | **Optional**. Character that barcode scanner prefixes input with. Code is only read if this character is read first. |
-| endCharacter | Character that barcode scanner suffixes input with. Code is only read if this character is read last. Defaults to line return (key code `13`)|
+| endCharacter | **Optional**. Character that barcode scanner suffixes input with. Code is evaluated early if this character is read. Defaults to line return and escape. |
 | onComplete | Function that is called when a complete barcode is scanned. Function is called with a single string which is the read code. |
@@ -30,0 +31,0 @@ | onError | **Optional**. Function that is called when an incomplete barcode is scanned. Function is called with a single string which is currently always `incomplete scan detected`|

src/__tests__/main.spec.ts

@@ -8,2 +8,6 @@ import { renderHook, act } from '@testing-library/react-hooks'
 
+    beforeEach(() => {
+        jest.spyOn(performance, 'now').mockImplementation(() => Math.random() * 50)
+    })
+
     afterEach(() => {
@@ -32,2 +36,3 @@ jest.clearAllTimers()
         }
+
         const result = renderHook(() => useScanDetection(config))
@@ -53,2 +58,3 @@
         }
+
         const result = renderHook(() => useScanDetection(config))
@@ -71,2 +77,5 @@
         }
+
+        jest.spyOn(performance, 'now').mockImplementation(() => 100)
+
         const result = renderHook(() => useScanDetection(config))
@@ -91,3 +100,3 @@
             onComplete: jest.fn(),
-            startCharacter: 49
+            startCharacter: [49]
         }
@@ -94,0 +103,0 @@ const result = renderHook(() => useScanDetection(config))

src/index.ts

@@ -7,13 +7,20 @@ import {
 
+interface bufferCharacter {
+    time: number,
+    char: String
+}
+
 interface buffer {
-    current: String
+    current: Array<bufferCharacter>
 }
 
 interface config {
-    /** Maximum time between characters in milliseconds. Used to determine if input is from keyboard or a scanner. Defaults to 50ms.*/
-    waitTime?: number,
+    /** Time to wait from last character to then trigger an evaluation of the buffer. */
+    timeToEvaluate?: number,
+    /** Average time between characters in milliseconds. Used to determine if input is from keyboard or a scanner. Defaults to 50ms.*/
+    averageWaitTime?: number,
     /** Character that barcode scanner prefixes input with.*/
-    startCharacter?: number,
+    startCharacter?: Array<number>,
     /** Character that barcode scanner suffixes input with. Defaults to line return.*/
-    endCharacter?: number,
+    endCharacter?: Array<number>,
     /** Callback to use on complete scan input.*/
@@ -40,5 +47,6 @@ onComplete: (code: String) => void,
 const useScanDetection = ({
-    waitTime = 50,
-    startCharacter,
-    endCharacter = 13,
+    timeToEvaluate = 100,
+    averageWaitTime = 50,
+    startCharacter = [],
+    endCharacter = [13, 27],
     onComplete,
@@ -53,25 +61,40 @@ onError,
 
-    const buffer: buffer = useRef("")
+    const buffer: buffer = useRef([])
     const timeout: any = useRef(false)
 
     const clearBuffer = () => {
-        buffer.current = ""
+        buffer.current = []
     }
 
+    const evaluateBuffer = () => {
+        clearTimeout()
+        const sum = buffer.current
+            .reduce((result, { time }) => result + time, 0)
+        const avg = sum / buffer.current.length
+
+        const code = buffer.current
+            .slice(startCharacter.length > 0 ? 1 : 0)
+            .map(({ char }) => char)
+            .join("")
+            
+        if (
+            avg <= averageWaitTime
+            && buffer.current.length >= minLength
+        ) {
+            onComplete(code)
+        } else {
+            !!onError && onError(code)
+        }
+        clearBuffer()
+    }
+
     const onKeyDown: Function = useCallback((event: KeyboardEvent) => {
         if (event.currentTarget !== ignoreIfFocusOn) {
-            if (event.keyCode === endCharacter) {
-                clearTimeout(timeout.current)
-                if (buffer.current.length >= minLength) {
-                    onComplete(buffer.current.slice(!!startCharacter ? 1 : 0))
-                }
-                else if (!!onError) {
-                    onError("incomplete scan detected")
-                }
-                clearBuffer()
+            if (endCharacter.includes(event.keyCode)) {
+                evaluateBuffer()
             }
-            if (buffer.current.length > 0 || event.keyCode === startCharacter || !startCharacter) {
+            if (buffer.current.length > 0 || startCharacter.includes(event.keyCode) || startCharacter.length === 0) {
                 clearTimeout(timeout.current)
-                timeout.current = setTimeout(clearBuffer, waitTime)
-                buffer.current += event.key
+                timeout.current = setTimeout(evaluateBuffer, timeToEvaluate)
+                buffer.current.push({ time: performance.now(), char: event.key })
             }
@@ -88,3 +111,3 @@ }
             endCharacter,
-            waitTime,
+            timeToEvaluate,
             onComplete,
@@ -91,0 +114,0 @@ onError,

tsconfig.json

@@ -6,3 +6,3 @@ {
     "lib": [
-      "es2015",
+      "es2016",
       "dom"
@@ -9,0 +9,0 @@ ],

No alert changes

Improved metrics

Total package byte prevSize

18183

increased by5.48%

Lines of code

383

increased by6.39%

Number of lines in readme file

65

increased by1.56%

No dependency changes