--- title: Mathematica pagination_prev: demos/cloud/index pagination_next: demos/bigdata/index --- import current from '/version.js'; :::note This demo was last tested in 2023 April 22 in Mathematica 13.2.1 ::: [The "NodeJS" instructions](/docs/getting-started/installation/frameworks) describe installation steps for NodeJS projects. Mathematica has built-in features for external scripting with NodeJS. Helper functions can translate between CSV text and Mathematica datasets or arrays. Mathematica can also use [command-line tools](/docs/demos/desktop/cli) ## Integration Details :::caution Mathematica includes `ExternalEvaluate` for running scripts in an external engine. In local testing, there were incompatibilities with recent NodeJS versions. This demo uses the shell integration to call a command-line tool. ::: ### Command-Line Tools `ExternalEvaluate` can run command-line tools and capture standard output: ```mathematica cmd = "/usr/local/bin/xlsx-cli ~/Downloads/pres.numbers" csvdata = ExternalEvaluate["Shell" -> "StandardOutput", cmd]; ``` Once evaluated, `ImportString` can interpret the data as a dataset. Typically the first row of the CSV output is the header row. The `HeaderLines` option controls how Mathematica parses the data: ```mathematica data = ImportString[csvdata, "Dataset", "HeaderLines" -> 1] ``` ## Complete Demo :::note This demo was tested in macOS. The path names will differ in other platforms. ::: 1) Create the standalone `xlsx-cli` binary:
{`\
cd /tmp
npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz exit-on-epipe commander@2
curl -LO https://docs.sheetjs.com/cli/xlsx-cli.js
npx nexe -t 14.15.3 xlsx-cli.js`}
This is discussed in ["Command-line Tools"](/docs/demos/desktop/cli) 2) Move the generated `xlsx-cli` to a fixed location in `/usr/local/bin`: ```bash mkdir -p /usr/local/bin mv xlsx-cli /usr/local/bin/ ``` ### Reading a Local File 3) In a new Mathematica notebook, run the following snippet: ```mathematica SheetJSImportFile[x_] := ImportString[Block[{Print}, ExternalEvaluate[ "Shell" -> "StandardOutput", "/usr/local/bin/xlsx-cli " <> x ]], "Dataset", "HeaderLines" -> 1] ``` 4) Download and save to Downloads folder. 5) In the Mathematica notebook, run the new function. If the file was saved to the Downloads folder, the path will be `"~/Downloads/pres.numbers"` in macOS: ```mathematica data = SheetJSImportFile["~/Downloads/pres.numbers"] ``` The result should be displayed in a concise table. ### Reading from a URL `FetchURL` downloads a file from a specified URL. This function will be wrapped in a new function called `SheetJSImportURL`. 6) In the same notebook, run the following: ```mathematica Needs["Utilities`URLTools`"]; SheetJSImportURL[x_] := Module[{path},( path = FetchURL["https://sheetjs.com/pres.numbers"]; SheetJSImportFile[path] )]; ``` 7) Test by downloading the test file in the notebook: ```mathematica data = SheetJSImportURL["https://sheetjs.com/pres.numbers"] ```