feat: wrap openFilePicker with useCallback (#92)

* feat: wrap openFilePicker with useCallback

* Add memoization to validator functions and a stable reference to empty validator array

* Bump version to v2.1.2

---------

Co-authored-by: MrKampla <mrkampla@gmail.com>

Author: Forsect

.eslintrc.json

@@ -0,0 +1,3 @@
+{
+  "extends": ["plugin:react-hooks/recommended"]
+}

package.json

@@ -1,7 +1,7 @@
 {
   "name": "use-file-picker",
   "description": "Simple react hook to open browser file selector.",
-  "version": "2.1.1",
+  "version": "2.1.2",
   "license": "MIT",
   "author": "Milosz Jankiewicz",
   "homepage": "https://github.com/Jaaneek/useFilePicker",
@@ -109,6 +109,7 @@
     "eslint-plugin-prettier": "^4.2.1",
     "husky": "^4.3.6",
     "jest": "^29.5.0",
+    "prettier": "2.8.8",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-is": "^17.0.1",

src/useFilePicker.ts

@@ -10,6 +10,10 @@ import {
 } from './interfaces';
 import { openFileDialog } from './helpers/openFileDialog';
 import { useValidators } from './validators/useValidators';
+import { Validator } from './validators';
+
+// empty array reference in order to avoid re-renders when no validators are passed as props
+const EMPTY_ARRAY: Validator[] = [];
 
 function useFilePicker<
   CustomErrors = unknown,
@@ -20,16 +24,18 @@ function useFilePicker<
     multiple = true,
     readAs = 'Text',
     readFilesContent = true,
-    validators = [],
+    validators = EMPTY_ARRAY,
     initializeWithCustomParameters,
   } = props;
 
   const [plainFiles, setPlainFiles] = useState<File[]>([]);
   const [filesContent, setFilesContent] = useState<FileContent<ExtractContentTypeFromConfig<ConfigType>>[]>([]);
   const [fileErrors, setFileErrors] = useState<UseFilePickerError<CustomErrors>[]>([]);
   const [loading, setLoading] = useState<boolean>(false);
-  const { onFilesSelected, onFilesSuccessfullySelected, onFilesRejected, onClear } =
-    useValidators<ConfigType, CustomErrors>(props);
+  const { onFilesSelected, onFilesSuccessfullySelected, onFilesRejected, onClear } = useValidators<
+    ConfigType,
+    CustomErrors
+  >(props);
 
   const clear: () => void = useCallback(() => {
     setPlainFiles([]);
@@ -42,45 +48,48 @@ function useFilePicker<
     onClear?.();
   }, [clear, onClear]);
 
-  const parseFile = (file: FileWithPath) =>
-    new Promise<FileContent<ExtractContentTypeFromConfig<ConfigType>>>(
-      async (
-        resolve: (fileContent: FileContent<ExtractContentTypeFromConfig<ConfigType>>) => void,
-        reject: (reason: UseFilePickerError) => void
-      ) => {
-        const reader = new FileReader();
-
-        //availible reader methods: readAsText, readAsBinaryString, readAsArrayBuffer, readAsDataURL
-        const readStrategy = reader[`readAs${readAs}` as ReaderMethod] as typeof reader.readAsText;
-        readStrategy.call(reader, file);
-
-        const addError = ({ ...others }: UseFilePickerError) => {
-          reject({ ...others });
-        };
-
-        reader.onload = async () =>
-          Promise.all(
-            validators.map(validator =>
-              validator.validateAfterParsing(props, file, reader).catch(err => Promise.reject(addError(err)))
-            )
-          )
-            .then(() =>
-              resolve({
-                ...file,
-                content: reader.result as string,
-                name: file.name,
-                lastModified: file.lastModified,
-              } as FileContent<ExtractContentTypeFromConfig<ConfigType>>)
+  const parseFile = useCallback(
+    (file: FileWithPath) =>
+      new Promise<FileContent<ExtractContentTypeFromConfig<ConfigType>>>(
+        async (
+          resolve: (fileContent: FileContent<ExtractContentTypeFromConfig<ConfigType>>) => void,
+          reject: (reason: UseFilePickerError) => void
+        ) => {
+          const reader = new FileReader();
+
+          //availible reader methods: readAsText, readAsBinaryString, readAsArrayBuffer, readAsDataURL
+          const readStrategy = reader[`readAs${readAs}` as ReaderMethod] as typeof reader.readAsText;
+          readStrategy.call(reader, file);
+
+          const addError = ({ ...others }: UseFilePickerError) => {
+            reject({ ...others });
+          };
+
+          reader.onload = async () =>
+            Promise.all(
+              validators.map(validator =>
+                validator.validateAfterParsing(props, file, reader).catch(err => Promise.reject(addError(err)))
+              )
             )
-            .catch(() => {});
-
-        reader.onerror = () => {
-          addError({ name: 'FileReaderError', readerError: reader.error, causedByFile: file });
-        };
-      }
-    );
+              .then(() =>
+                resolve({
+                  ...file,
+                  content: reader.result as string,
+                  name: file.name,
+                  lastModified: file.lastModified,
+                } as FileContent<ExtractContentTypeFromConfig<ConfigType>>)
+              )
+              .catch(() => {});
+
+          reader.onerror = () => {
+            addError({ name: 'FileReaderError', readerError: reader.error, causedByFile: file });
+          };
+        }
+      ),
+    [props, readAs, validators]
+  );
 
-  const openFilePicker = () => {
+  const openFilePicker = useCallback(() => {
     const fileExtensions = accept instanceof Array ? accept.join(',') : accept;
     openFileDialog(
       fileExtensions,
@@ -156,7 +165,19 @@ function useFilePicker<
       },
       initializeWithCustomParameters
     );
-  };
+  }, [
+    props,
+    accept,
+    clear,
+    initializeWithCustomParameters,
+    multiple,
+    onFilesRejected,
+    onFilesSelected,
+    onFilesSuccessfullySelected,
+    parseFile,
+    readFilesContent,
+    validators,
+  ]);
 
   return {
     openFilePicker,

src/validators/useValidators.ts

@@ -1,3 +1,4 @@
+import { useCallback } from 'react';
 import {
   SelectedFilesOrErrors,
   ExtractContentTypeFromConfig,
@@ -14,30 +15,39 @@ export const useValidators = <ConfigType extends UseFilePickerConfig<CustomError
   validators,
 }: ConfigType) => {
   // setup validators' event handlers
-  const onFilesSelected = (data: SelectedFilesOrErrors<ExtractContentTypeFromConfig<ConfigType>, CustomErrors>) => {
-    onFilesSelectedProp?.(data as any);
-    validators?.forEach(validator => {
-      validator.onFilesSelected(data as any);
-    });
-  };
-  const onFilesSuccessfullySelected = (data: SelectedFiles<ExtractContentTypeFromConfig<ConfigType>>) => {
-    onFilesSuccessfullySelectedProp?.(data as any);
-    validators?.forEach(validator => {
-      validator.onFilesSuccessfullySelected(data);
-    });
-  };
-  const onFilesRejected = (errors: FileErrors<CustomErrors>) => {
-    onFilesRejectedProp?.(errors);
-    validators?.forEach(validator => {
-      validator.onFilesRejected(errors);
-    });
-  };
-  const onClear = () => {
+  const onFilesSelected = useCallback(
+    (data: SelectedFilesOrErrors<ExtractContentTypeFromConfig<ConfigType>, CustomErrors>) => {
+      onFilesSelectedProp?.(data as any);
+      validators?.forEach(validator => {
+        validator.onFilesSelected(data as any);
+      });
+    },
+    [onFilesSelectedProp, validators]
+  );
+  const onFilesSuccessfullySelected = useCallback(
+    (data: SelectedFiles<ExtractContentTypeFromConfig<ConfigType>>) => {
+      onFilesSuccessfullySelectedProp?.(data as any);
+      validators?.forEach(validator => {
+        validator.onFilesSuccessfullySelected(data);
+      });
+    },
+    [validators, onFilesSuccessfullySelectedProp]
+  );
+  const onFilesRejected = useCallback(
+    (errors: FileErrors<CustomErrors>) => {
+      onFilesRejectedProp?.(errors);
+      validators?.forEach(validator => {
+        validator.onFilesRejected(errors);
+      });
+    },
+    [validators, onFilesRejectedProp]
+  );
+  const onClear = useCallback(() => {
     onClearProp?.();
     validators?.forEach(validator => {
       validator.onClear?.();
     });
-  };
+  }, [validators, onClearProp]);
 
   return {
     onFilesSelected,

yarn.lock

@@ -6464,7 +6464,7 @@ eslint-plugin-prettier@^4.2.1:
 
 eslint-plugin-react-hooks@^4.6.0:
   version "4.6.0"
-  resolved "https://registry.npmjs.org/eslint-plugin-react-hooks/-/eslint-plugin-react-hooks-4.6.0.tgz"
+  resolved "https://registry.yarnpkg.com/eslint-plugin-react-hooks/-/eslint-plugin-react-hooks-4.6.0.tgz#4c3e697ad95b77e93f8646aaa1630c1ba607edd3"
   integrity sha512-oFc7Itz9Qxh2x4gNHStv3BqJq54ExXmfC+a1NjAta66IAN87Wu0R/QArgIS9qKzX3dXKPI9H5crl9QchNMY9+g==
 
 eslint-plugin-react@^7.31.11:
@@ -11039,6 +11039,11 @@ prettier-linter-helpers@^1.0.0:
   dependencies:
     fast-diff "^1.1.2"
 
+prettier@2.8.8:
+  version "2.8.8"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.8.8.tgz#e8c5d7e98a4305ffe3de2e1fc4aca1a71c28b1da"
+  integrity sha512-tdN8qQGvNjw4CHbY+XXk0JgCXn9QiF21a55rBe5LJAU+kDyC4WQn4+awm2Xfk2lQMk5fKup9XgzTZtGkjBdP9Q==
+
 "prettier@>=2.2.1 <=2.3.0":
   version "2.3.0"
   resolved "https://registry.npmjs.org/prettier/-/prettier-2.3.0.tgz"