new-function-in-formula.md

Custom functions for Formula

EspoCRM provides the ability to create custom functions that can be used in formula-script.

Create a file custom/Espo/Custom/FormulaFunctions/MyContains.php with the code:

<?php
namespace Espo\Custom\FormulaFunctions;

use Espo\Core\Formula\Functions\BaseFunction;
use Espo\Core\Formula\ArgumentList;

class MyContains extends BaseFunction
{
    public function process(ArgumentList $args)
    {
        if (count($args) < 2) {
            $this->throwTooFewArguments();
        }

        $haystack = $this->evaluate($args[0]);
        $needle =  $this->evaluate($args[1]);

        if (count($args) > 2) {
            $offset = $this->evaluate($args[2]);
            
            return strpos($haystack, $needle, $offset) !== false;
        }
        
        // target entity:
        // $this->entity
        
        // variables:
        // $this->variables
        
        return strpos($haystack, $needle) !== false;
    }
}

Create a file custom/Espo/Custom/Resources/metadata/app/formula.json and add the code:

{
    "functionClassNameMap": {
        "myNamespace\\myContains": "Espo\\Custom\\FormulaFunctions\\MyContains"
    },
    "functionList": [
        "__APPEND__",
        {
            "name": "myNamespace\\myContains",
            "insertText": "myNamespace\\myContains(HAYSTACK, NEEDLE, OFFSET)"
        }
    ]
}

Clear cache.

Func interface

As of v7.4.

Instead of extending BaseFunction, you can implement Espo\Core\Formula\Func interface. This allows to inject any dependency to the function class via the constructor. Values passed to the process method are already evaluated.