Docs: expanding the Custom Functions topic

[kirszenbaum]

#557

In Custom Functions:

• Added an "Optional parameters" section, based on this
• Added an "Argument validation options" section, based on this
• Added a "runFunction()" section
• Added a "Throwing errors" section, based on this

[codecov]

Codecov Report

Merging #758 (3cf186b) into develop (321406c) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff            @@
##           develop     #758   +/-   ##
========================================
  Coverage    92.35%   92.35%           
========================================
  Files          166      166           
  Lines        40311    40330   +19     
  Branches      5569     5569           
========================================
+ Hits         37229    37248   +19     
  Misses        3039     3039           
  Partials        43       43           

Impacted Files	Coverage Δ
src/interpreter/plugin/FunctionPlugin.ts	81.63% <100.00%> (+0.72%)	⬆️

[wojciechczerniak]

Wrong formatting and I think we're missing plugin class here

Suggested change

	public hyper({ args }) {
	if (!args.length) {
	// create a `CellError` instance with an `ErrorType` of `DIV_BY_ZERO`
	// with your custom error message (optional)
	return new CellError(ErrorType.DIV_BY_ZERO, 'Sorry, cannot divide by zero!');
	}
	else {
	return 'Hyperformula'.length;
	}
	};
	export class CountHF extends FunctionPlugin {
	public hyper({ args }) {
	if (!args.length) {
	// create a `CellError` instance with an `ErrorType` of `DIV_BY_ZERO`
	// with your custom error message (optional)
	return new CellError(ErrorType.DIV_BY_ZERO, 'Sorry, cannot divide by zero!');
	}
	else {
	return 'Hyperformula'.length;
	}
	};
	}

All imports are already in place

[wojciechczerniak]

Or make it more obvious that we're focusing on the body of our method because complete functions will be added below. Then we should remove the imports, fix indentation, add a comment that this is part of the CountHF class etc

[kirszenbaum]

@wojciechczerniak - sure. I think I'd rather display the whole example (except optional parameters) in each step, WDYT? I also checked the indendation in all the code samples: 5b0f149

[wojciechczerniak]

🤔 With translations and aliases it's a little bit harder to find what has changed between steps. Also the "complete" examples is a copy of last step without any changes and this sections makes little sense. But I don't have a better idea right now

[wojciechczerniak]

The complete examples is now shorter than each step 😄 We should update the example below

[wojciechczerniak]

Ale at the bottom of the page we have CodeSandbox with working demo. We should make sure it's up do date with this tutorial

[kirszenbaum]

@wojciechczerniak - done: 5b0f149

@jansiegel - can we update the demo to include:

• Optional parameters
• Argument validation options
• Aliases
• Translations
• The runFunction() wrapper
• Returning errors

Thanks for your help!

[wojciechczerniak]

With translations added as static key on the plugin class the "using plugin" section have to change:

import Hyperformula, { plPL } from 'hyperformula';
import { CountHF } from './file_with_your_custom_function';
- import { myTranslations } from '/myTranslationFile';

// register the language
HyperFormula.registerLanguage('plPL', plPL);

// register your custom plugin and the translation
- HyperFormula.registerFunctionPlugin(CountHF, myTranslations);
+ HyperFormula.registerFunctionPlugin(CountHF, CountHF.translations);

// build HF instance where you can use the function directly
const hfInstance = HyperFormula.buildFromArray([['=HAJPER()']]);

// read the value of cell A1
const A1Value = hfInstance.getCellValue({ sheet: 0, col: 0, row: 0 });

// open the browser's console to see the results
console.log(A1Value);

[kirszenbaum]

@wojciechczerniak - translation updated: a1f532b, d786b8a

[wojciechczerniak]

🏆