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# Fs

## fs : `object`

Basic filesystem access utility functions, wrapping Node.JS and/or NW.JS code.

Kind: global namespace

- fs : `object`
  - .openFileSaveDialog(suggestedFilename, fileExtensions) ⇒ `Promise.<(string|null)>`
  - .openFileBrowseDialog(chooseFolder, accept, dialogTitle) ⇒ `string` | `null`
  - .writeFile(filename, data, encoding, flag) ⇒ `Promise`
  - .readFile(filename, encoding, flag) ⇒ `Promise.<(string|Buffer)>`
  - .fileExists(filename) ⇒ `boolean`

### fs.openFileSaveDialog(suggestedFilename, fileExtensions) ⇒ `Promise.<(string|null)>`

Open a file save as dialog prompting the user to save a file. Opens to the user's Documents folder, with sane fallbacks if it cannot be located.

Kind: static method of `fs`
Returns: `Promise.<(string|null)>` - The full file path the user selected, or null if they cancelled.

Param | Type | Description
--- | --- | ---
suggestedFilename | `string` | The filename string to pre-fill in the dialog.
fileExtensions | `string` | The file type filter to show. Examples: ".csv", ".csv,.html"

### fs.openFileBrowseDialog(chooseFolder, accept, dialogTitle) ⇒ `string` | `null`

Open a file browse/file open dialog prompting the user to select a file or folder. Opens to the user's Documents folder, with sane fallbacks if it cannot be located.

Kind: static method of `fs`
Returns: `string` | `null` - The selected file/folder path, or null if cancelled.

Param | Type | Default | Description
--- | --- | --- | ---
chooseFolder | `boolean` | `false` | Set to true to choose a folder instead of a file.
accept | `string` |  | File filter. ".csv,.html", "image/*", etc.
dialogTitle | `string` | `null` | `null` | Title of the file open dialog.

### fs.writeFile(filename, data, encoding, flag) ⇒ `Promise`

Write a file to disk.

Kind: static method of `fs`

Param | Type | Default | Description
--- | --- | --- | ---
filename | `string` |  | The path and filename to write to.
data | `string` | `Buffer` | `ArrayBuffer` | `Uint8Array` |  | Data to write to the file.
encoding | `string` | `null` | `"utf8"` | Text encoding. Set to empty if not passing string data.
flag | `string` | `null` | `"w+"` | Filesystem flag.

### fs.readFile(filename, encoding, flag) ⇒ `Promise.<(string|Buffer)>`

Read a file from disk and return its contents.

Kind: static method of `fs`

Param | Type | Default | Description
--- | --- | --- | ---
filename | `string` |  | The path and filename to read from.
encoding | `string` | `"utf8"` | File encoding. Set to null or empty string when reading binary data.
flag | `string` | `"r+"` | Filesystem flag.

### fs.fileExists(filename) ⇒ `boolean`

Check if a file exists.

Kind: static method of `fs`

Param | Type | Description
--- | --- | ---
filename | `string` | Path and filename to check.