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extractUserName — GTM Variable Template for URL

VARIABLES › URL
extractUserName EXTENDED URL
Direct (.tpl) Apply (.tpl)

Extracts the username from a URL with authentication credentials.

When to Use This

Section titled “When to Use This”

Examples

Section titled “Examples”
Extract username
INPUT
URL: https://[email protected]/path
OUTPUT
john
No username returns undefined
INPUT
URL: https://example.com/path
OUTPUT
undefined

GTM Configuration

Section titled “GTM Configuration”

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Read-only Preview
extractUserName
URL
💾 The URL to extract the username from.

Supported formats:
  ✓ String
Input Setup
Input Function (optional)
⚙️ Optional pre-processing function applied to the input before internal logic (e.g., convert object to string, normalize case). Internal transformations such as case handling will still apply afterward.
Result Handling
Output Function (optional)
⚙️ Optional function to apply to the result before returning it (e.g., str => str + ' €', val => val !== undefined for boolean conversion). Useful for chaining transformations on the output.
Section titled “Related Variables”

Same category: URL

→ assignParamsToString → buildUrlFromParts → completeUrl → decodeUri → decodeUriComponent → encodeURIComponent → encodeUri → extractHash → extractHashParams → extractHost → extractHostname → extractOrigin → extractPasword → extractPathname → extractPort → extractProtocol → extractSearch → extractSearchParams → extractSegmentByIndex → hasFragment → hasParameterWithValue → hasQueryString → omitParamsFromString → parseUrlComponents → pickParamsFromString → stringToPath → ⚡ URL › Transformer

Under the Hood

Section titled “Under the Hood”
📜 View Implementation Code
/**
 * Extracts the username from a given URL.
 *
 * @param {string} data.src - The URL to extract the username from.
 * @param {Function|string} [data.out] - Optional output handler: function to transform result or string with format.
 *
 * Direct-mode specific parameters:
 * @param {Function} [data.pre] - Optional pre-processor function to transform src before extracting.
 *
 * @returns {string|undefined} The username from the URL, or undefined if the input is invalid.
 *
 * @framework ggLowCodeGTMKit
 */


const parseUrl = require('parseUrl');


const extractUserName = function(url) {
    const parsed = parseUrl(url);
    return parsed && parsed.username || undefined;
};


const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);


// ===============================================================================
// extractUserName - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(extractUserName(value));


// ===============================================================================
// extractUserName() – Apply Mode: runtime parameter
// ===============================================================================
/*
return function(value) {
   return out(extractUserName(value));
};
*/
🧪 View Test Scenarios (5 tests)
✅ '[example] Extract username'
✅ URL with username and password - extracts only username
✅ '[example] No username returns undefined'
✅ Invalid URL - returns undefined
✅ Empty string input - returns undefined