docs.sheetjs.com/docz/docs/03-demos/32-extensions/12-maple.md

---
title: Modern Spreadsheets in Maple
sidebar_label: Maple
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---

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[Maple](https://www.maplesoft.com/products/Maple/) is a numeric computing
platform. It offers a robust C-based extension system.

[SheetJS](https://sheetjs.com) is a JavaScript library for reading and writing
data from spreadsheets.

This demo uses SheetJS to pull data from a spreadsheet for further analysis
within Maple. We'll create a Maple native extension that loads the
[Duktape](/docs/demos/engines/duktape) JavaScript engine and uses the SheetJS
library to read data from spreadsheets and converts to a Maple-friendly format.

```mermaid
flowchart LR
  ofile[(workbook\nXLSB file)]
  nfile[(clean file\nXLSX)]
  data[[Maple\nTable]]
  ofile --> |Maple Extension\nSheetJS + Duktape| nfile
  nfile --> |ExcelTools\nImport|data
```

:::note Tested Deployments

This demo was last tested by SheetJS users on 2023 October 3 in Maple 2023.

:::

:::info pass

Maple has limited support for processing spreadsheets through the `ExcelTools`
package[^1]. At the time of writing, it lacked support for XLSB, NUMBERS, and
other common spreadsheet formats.

SheetJS libraries help fill the gap by normalizing spreadsheets to a form that
Maple can understand.

:::

## Integration Details

The current recommendation involves a native plugin that reads arbitrary files
and generates clean XLSX files that Maple can import.

The extension function ultimately pairs the SheetJS `read`[^2] and `write`[^3]
methods to read data from the old file and write a new file:

```js
var wb = XLSX.read(original_file_data, {type: "buffer"});
var new_file_data = XLSX.write(wb, {type: "array", bookType: "xlsx"});
```

The extension function will receive a file name and perform the following steps:

```mermaid
flowchart LR
  ofile{{File\nName}}
  subgraph JS Operations
    ojbuf[(Buffer\nFile Bytes)]
    wb(((SheetJS\nWorkbook)))
    njbuf[(Buffer\nXLSX bytes)]
  end
  obuf[(File\nbytes)]
  nbuf[(New file\nbytes)]
  nfile[(XLSX\nFile)]
  ofile --> |C\nRead File| obuf
  obuf --> |Duktape\nBuffer Ops| ojbuf
  ojbuf --> |SheetJS\n`read`| wb
  wb --> |SheetJS\n`write`| njbuf
  njbuf --> |Duktape\nBuffer Ops| nbuf
  nbuf --> |C\nWrite File| nfile
```

### C Extensions

Maple C extensions are shared libraries or DLLs that use special Maple methods
for parsing arguments and returning values.

To simplify the flow, the new function will take one argument (the original file
name) and return one value (the new file name).

The official documentation has a comprehensive list[^4] of methods. For this
demo, the following methods are used:

- `MapleNumArgs` and `IsMapleString` are used in argument validation. The demo
function will raise a Maple exception if no file name is specified.

- `MapleRaiseError` and `MapleRaiseError2` programmatically raise errors.

- `MapleToString` and `ToMapleString` convert between Maple and C strings.

### Duktape JS Engine

This demo uses the [Duktape JavaScript engine](/docs/demos/engines/duktape). The
SheetJS + Duktape demo covers engine integration details in more detail.

The [SheetJS Standalone scripts](/docs/getting-started/installation/standalone)
can be loaded in Duktape by reading the source from the filesystem.

## Complete Demo

:::info pass

This demo was tested in Windows x64. The path names and build commands will
differ in other platforms and operating systems.

:::

The [`sheetjs-maple.c`](pathname:///maple/sheetjs-maple.c) extension exports the
`SheetToXLSX` Maple method. It takes a file name argument, parses the specified
file, exports data to `sheetjsw.xlsx` and returns the string `"sheetjsw.xlsx"`.

This can be chained with `Import` from `ExcelTools`:

```maple
with(ExcelTools);
Import(SheetToXLSX("pres.numbers"))
```

0) Ensure "Windows Subsystem for Linux" (WSL) and Visual Studio are installed.

1) Open a new "x64 Native Tools Command Prompt" window and create a project
folder `c:\sheetjs-maple`:

```powershell
cd c:\
mkdir sheetjs-maple
cd sheetjs-maple
```

2) Copy the headers and `lib` files from the Maple folder to the project folder.
For example, using Maple 2023 on Windows x64:

```powershell
copy "C:\Program Files\Maple 2023\extern\include\"*.h .
copy "c:\Program Files\Maple 2023\bin.x86_64_WINDOWS"\*.lib .
```

3) Run `bash` to enter WSL

4) Within WSL, install Duktape:

```bash
curl -LO https://duktape.org/duktape-2.7.0.tar.xz
tar -xJf duktape-2.7.0.tar.xz
mv duktape-2.7.0/src/*.{c,h} .
```

5) Still within WSL, download SheetJS scripts and the test file.

<CodeBlock language="bash">{`\
curl -LO https://cdn.sheetjs.com/xlsx-${current}/package/dist/shim.min.js
curl -LO https://cdn.sheetjs.com/xlsx-${current}/package/dist/xlsx.full.min.js
curl -LO https://sheetjs.com/pres.numbers`}
</CodeBlock>

6) Still within WSL, download the extension C code

```bash
curl -LO https://docs.sheetjs.com/maple/sheetjs-maple.c
```

7) Exit WSL by running `exit`. The window will return to the command prompt.

8) Build the extension DLL:

```powershell
cl -Gz sheetjs-maple.c duktape.c /EHsc -link -dll -out:sheetjs-maple.dll maplec.lib
```

9) Close and re-open Maple, then create a new Maple Worksheet or Document

10) Run the following command in Maple to change the working directory:

```maple
currentdir("c:\\sheetjs-maple");
```

11) Load the `SheetToXLSX` method from the extension:

```maple
with(ExternalCalling):
dll:=ExternalLibraryName("sheetjs-maple"):
SheetToXLSX:=DefineExternal("SheetToXLSX",dll):
```

12) Read the `pres.numbers` test file:

```maple
with(ExcelTools);
Import(SheetToXLSX("pres.numbers"))
```

The result will show the data from `pres.numbers`

![Maple Screenshot](pathname:///maple/maple.png)

[^1]: See ["ExcelTools"](https://www.maplesoft.com/support/help/Maple/view.aspx?path=ExcelTools) in the Maple documentation.
[^2]: See [`read` in "Reading Files"](/docs/api/parse-options)
[^3]: See [`write` in "Writing Files"](/docs/api/write-options)
[^4]: See ["C OpenMaple and ExternalCalling Application Program Interface (API)"](https://www.maplesoft.com/support/help/maple/view.aspx?path=OpenMaple%2FC%2FAPI) in the Maple documentation.