Can't get the custom functions to work

[vhpoet]

Followed your readme to come up with the below code which throws a Function name METRIC not recognized.. What am I doing wrong? Here's the codesandbox. Might be the same bug as this.

import HyperFormula, { FunctionPlugin } from "hyperformula";

class MetricPlugin extends FunctionPlugin {
  static implementedFunctions = {
    METRIC: {
      method: "metric"
    }
  };

  metric(ast, state) {
    return this.runFunction(ast, state, this.metadata('METRIC'), () => 63);
  }
}

export default function App() {
  HyperFormula.registerFunctionPlugin(MetricPlugin);

  const hfInstance = HyperFormula.buildFromArray([["=METRIC()"]], {
    licenseKey: "gpl-v3"
  });

  const value = hfInstance.getCellValue({ sheet: 0, col: 0, row: 0 });

  console.log(value);

  return null;
}

[sequba]

@vhpoet I am sorry you experienced an issue with HyperFormula. Our guide on custom functions is outdated and contains misleading information. We will fix it soon (#968).

Here is a working example of a simple custom function that you can use. It does not use the helper method runFunction but for functions with no arguments it is not necessary.

In case of your code - it requires a few things to make it work:

• you need to add translations for your function
• if you want to use runFunction you must pass ast.args as its first parameter
• if you want to use runFunction you must specify the parameters array in the function metadata

After applying these fixes:

import HyperFormula, { FunctionPlugin } from "hyperformula";

class MetricPlugin extends FunctionPlugin {
  static implementedFunctions = {
    METRIC: {
      method: "metric",
      parameters: []
    }
  };

  static translations = {
    'enGB': {
      'METRIC': 'METRIC'
    },
  }

  metric(ast, state) {
    return this.runFunction(ast.args, state, this.metadata('METRIC'), () => 63);
  }
}

export default function App() {
  HyperFormula.registerFunctionPlugin(MetricPlugin, MetricPlugin.translations);

  const hfInstance = HyperFormula.buildFromArray([["=METRIC()"]], {
    licenseKey: "gpl-v3"
  });

  const value = hfInstance.getCellValue({ sheet: 0, col: 0, row: 0 });

  console.log(value);

  return null;
}

[vhpoet]

ok that works, thanks for the detailed answer!

[sequba]

@vhpoet With HyperFormula 2.0.1 we updated our guide about custom functions. You may want to have a look at it: https://handsontable.github.io/hyperformula/guide/custom-functions.html

[sequba]

@vhpoet, we've just released a new custom functions guide with an advanced example. You should check it out ;)