docs.sheetjs.com/docz/docs/03-demos/42-engines/06_goja.md

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---
title: Go + Goja
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pagination_prev: demos/bigdata/index
pagination_next: solutions/input
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---
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import current from '/version.js';
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import CodeBlock from '@theme/CodeBlock';
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Goja is a pure Go implementation of ECMAScript 5.
The [Standalone scripts](/docs/getting-started/installation/standalone) can be
parsed and evaluated in a Goja context.
## Integration Details
_Initialize Goja_
Goja does not provide a `global` variable. It can be created in one line:
```go
/* initialize */
vm := goja.New()
/* goja does not expose a standard "global" by default */
// highlight-next-line
v, err := vm.RunString("var global = (function(){ return this; }).call(null);")
```
_Load SheetJS Scripts_
The shim and main libraries can be loaded by reading the scripts from the file
system and evaluating in the Goja context:
```go
func safe_run_file(vm *goja.Runtime, file string) {
data, err := ioutil.ReadFile(file)
if err != nil { panic(err) }
src := string(data)
_, err = vm.RunString(src)
if err != nil { panic(err) }
}
// ...
safe_run_file(vm, "shim.min.js")
safe_run_file(vm, "xlsx.full.min.js")
```
To confirm the library is loaded, `XLSX.version` can be inspected:
```go
/* get version string */
v, err := vm.RunString("XLSX.version")
fmt.Printf("SheetJS library version %s\n", v)
```
### Reading Files
Files can be read into `[]byte`:
```go
/* read file */
data, _ := ioutil.ReadFile("sheetjs.xlsx")
```
`[]byte` should be converted to an `ArrayBuffer` from Go:
```go
/* load into engine */
vm.Set("buf", vm.ToValue(vm.NewArrayBuffer(data)))
/* parse */
wb, _ = vm.RunString("wb = XLSX.read(buf, {type:'buffer'});")
```
### Writing Files
`"base64"` strings can be passed from the JS context to Go code:
```go
/* write to Base64 string */
b64str, _ := vm.RunString("XLSX.write(wb, {type:'base64', bookType:'xlsx'})")
/* pull data back into Go and write to file */
buf, _ := base64.StdEncoding.DecodeString(b64str.String())
_ = ioutil.WriteFile("sheetjs.xlsx", buf, 0644)
```
## Complete Example
:::note
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This demo was tested in the following deployments:
| Architecture | Git Commit | Go version | Date |
|:-------------|:-----------|:-----------|:-----------|
| `darwin-x64` | `28ee0ee` | `1.19.3` | 2023-06-05 |
| `darwin-arm` | `28ee0ee` | `1.20.4` | 2023-06-05 |
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| `win10-x64` | `81d7606` | `1.20.2` | 2023-08-27 |
| `linux-x64` | `81d7606` | `1.21.0` | 2023-08-27 |
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:::
0) Create a module and install dependencies:
```bash
mkdir SheetGoja
cd SheetGoja
go mod init SheetGoja
go get github.com/dop251/goja
```
1) Download the standalone script, shim and test file:
<ul>
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<li><a href={`https://cdn.sheetjs.com/xlsx-${current}/package/dist/xlsx.full.min.js`}>xlsx.full.min.js</a></li>
<li><a href={`https://cdn.sheetjs.com/xlsx-${current}/package/dist/shim.min.js`}>shim.min.js</a></li>
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<li><a href="https://sheetjs.com/pres.numbers">pres.numbers</a></li>
</ul>
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<CodeBlock language="bash">{`\
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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`}
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</CodeBlock>
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2) Download [`SheetGoja.go`](pathname:///goja/SheetGoja.go):
```bash
curl -LO https://docs.sheetjs.com/goja/SheetGoja.go
```
3) Build standalone `SheetGoja` binary:
```bash
go build SheetGoja.go
```
4) Run the demo:
```bash
./SheetGoja pres.numbers
```
If the program succeeded, the CSV contents will be printed to console and the
file `sheetjsw.xlsb` will be created. That file can be opened with Excel.