---
title: "Write and read files"
slug: "save-and-read-files"
updated: 2026-04-13T08:14:36Z
published: 2026-04-13T08:14:36Z
canonical: "docs.grassfish.com/save-and-read-files"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.grassfish.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Write and read files

The player allows the application to write data to the hard drive and to read it from the application itself or from another application.

## Write a file to the player

Writes a file to the player.

| Parameters | `function(directory, fileName, data)` **directory** is the subdirectory in which the file is stored. **fileName** is the name of the file and the file extension, for example, .json or .xml. **data** is the data as a string. The string can contain XML or JSON data. All spots that want to use this file must use the same structure. |
| --- | --- |
| Examples | `GFSpotBase.writeFile("sampleData/","sample.xml","<product><id>243</id><name>Some Product Name</name></product>");` |
| Players | Windows Player version 7.7 or later Linux Player version 8.0 or later Android Player version 8.1.0.0 or later |

## Read a file from the player

To load the data of a previously saved file into the HTML application, the method `GFSpotBase.receiveOnReadFile` must first be overwritten.

Use the `init()` method after the `<body onload="init()">`:

```javascript
function init() {
  // Override the receiver function
  GFSpotBase.receiveOnReadFile = function (fileName, data) {
    // do something with the data
  };

  // Request the data
  GFSpotBase.readFile("sampleData/", "sample.xml");
}
```

## Retrieve all spots from the playlist

To poll the playlist data in the HTML application, the method `GFSpotBase.receiveOnGetAllSpots` must be overwritten first.

Use the `init()` method after the `<body onload="init()">`:

```javascript
function init() {
  // Override the receiver function
  GFSpotBase.receiveOnGetAllSpots = function (data) {
    // do something with the data
  };

  // Request the data
  GFSpotBase.getAllSpots();
}
```

| Function | Lets the spot retrieve a list of all spots in the playlist, for example, to jump from a central control spot to other spots. The return takes place analogously to `readFile()` via a return function. |
| --- | --- |
| Parameters | None |
| Players | Windows and Linux Player version 10.1 or later Android Player version 8.1.0.0 or later |

Example response:

```json
{
  "Spots":[
    {
      "BlockID":"4760",
      "BlockName":"Any default playlist",
      "Overlay":"false",
      "ScreenNr":"1",
      "SplitNr":"0",
      "SpotName":"SpotSelector Website",
      "SpotID":"32709",
      "SpotInstanceID":"69820",
      "ThumbFilePath":"http://localhost:9090/thumb/_32709-5191-Manual-DefaultIXM One80X60-1-1.png",
      "EventType":"null",
      "EventValue":"null",
      "FilePath":"http://localhost:9090/_32709_v.1_WebsiteSpot.xml"
    },
    {
      "BlockID":"4762",
      "BlockName":"Some Image Event Playlist",
      "Overlay":"false",
      "ScreenNr":"1",
      "SplitNr":"0",
      "SpotName":"Flowers A",
      "SpotID":"32150",
      "SpotInstanceID":"68697",
      "ThumbFilePath":"http://localhost:9090/thumb/_32150-4762-Automatic-DefaultIXM One80X60-1-1.png",
      "EventType":"Start",
      "EventValue":"123",
      "FilePath":"http://localhost:9090/newNum_02.jpg"
    },
    {
      "BlockID":"4630",
      "BlockName":"Idle Playlist Test",
      "Overlay":"false",
      "ScreenNr":"1",
      "SplitNr":"0",
      "SpotName":"Grassfish Website",
      "SpotID":"25298",
      "SpotInstanceID":"63863",
      "ThumbFilePath":"http://localhost:9090/thumb/_25298-3227-Manual-DefaultIXM One80X60-1-1.png",
      "EventType":"IdleSeconds",
      "EventValue":"10",
      "FilePath":"http://localhost:9090/_25298_v.10_WebsiteSpot.xml"
    },
    {
      "BlockID":"4626",
      "BlockName":"Time Playlist Test",
      "Overlay":"false",
      "ScreenNr":"1",
      "SplitNr":"0",
      "SpotName":"Pictures-36",
      "SpotID":"25491",
      "SpotInstanceID":"63854",
      "ThumbFilePath":"http://localhost:9090/thumb/_25491-1007-Automatic-DefaultIXM One80X60-1-1.png",
      "EventType":"Time",
      "EventValue":"12:00:00 18:00:00",
      "FilePath":"http://localhost:9090/_25491_v.1_Pictures_36.jpg"
    }
  ]
}
```