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Partially-Applied Function – Practical Example

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This example demonstrates several concepts:
  • modules
  • partially applied functions
  • functional programming techniques
The partialGetElID function creates a partially applied function that replaces hyphenated, underscored, or dotted names with their camelCased variant. 
module.exports = {
    partialGetElID: (wf, pg) =>el=>`${sepsToCamelCase(wf)}-${sepsToCamelCase(pg)}-${sepsToCamelCase(el)}`
};

var sepsToCamelCase = function(arg) {

    var upperFirst = s => s.replace(s.charAt(0), s.charAt(0).toUpperCase());
    var lowerFirst = s => s.replace(s.charAt(0), s.charAt(0).toLowerCase());

    return (
        R.pipe(
            R.split(/[._-]/g),
            R.map(upperFirst),
            R.join(''),
            lowerFirst
        )(arg)
    );
};
Usage: 

var X = require('path/to/module');
var getID = X.partialGetElId('workflow.name', 'step_name');

getID('element-name') // returns workflowName-stepName-elementName
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