extract — GTM Variable Template for String

VARIABLES › STRING

extract CORE String

Direct (.tpl) Apply (.tpl)

Extracts from a string using regex. Returns first capture group if present, otherwise full match. Returns undefinedif no match found.

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When to Use This

String Manipulation

Transform, clean, and normalize text data for consistent downstream processing.

Extraction

Pull specific values, segments, or patterns from complex data structures.

Comparison

Test equality, containment, and ordering between values.

Regex

Pattern matching, extraction, and replacement using regular expressions.

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Examples

Extract numbers from string▶ Try

INPUT

String To Extract From: Hello World 123
Regex Pattern: \\d+

OUTPUT

123

Non-string input returns undefined▶ Try

INPUT

String To Extract From: 12345
Regex Pattern: \\d+

OUTPUT

undefined

GA cookie CID extraction▶ Try

INPUT

String To Extract From: GA1.1.790863531.1759168565
Regex Pattern: \\d+\\.\\d+\\.(\\d+\\.\\d+)$

OUTPUT

790863531.1759168565

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GTM Configuration

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extract

Read-Only Try Live

String To Extract From

Extracts from a string using regex. Returns first capture group if present, otherwise full match. Returns undefined if no match found.

*** Extract numbers from string***
Input: String To Extract From: Hello World 123
Regex Pattern: \d+
↪️ Output: 123

*** Non-string input returns undefined***
Input: String To Extract From: 12345
Regex Pattern: \d+
↪️ Output: undefined

*** GA cookie CID extraction***
Input: GA1.1.790863531.1759168565
↪️ Output: 790863531.1759168565

Regex Pattern

💾 A regular expression pattern used for extraction.

Supported formats:
  ✓ String

The Regex Pattern input allows the definition of the regular expression to test for matches in the provided parameter. In this environment, a single backslash () is permitted within the regular expression.

Supports capturing groups, but does not support flag groups (e.g., (?i) for case-insensitivity).

The regular expression is case-sensitive by default.

✏️ Example Patterns:
d: Matches any digit (0-9).
w: Matches any word character (letters, digits, and underscores).
s: Matches any whitespace character (spaces, tabs, etc.).

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.

String To Extract From string

💡 Type any text to see the result update live

🎯 Using special value — click input to type instead

Test with:

Falsy undefined null "" empty 0 false NaN

Truthy true 42 "hello" {} empty [] empty {a:1} [1,2,3]

Regex Pattern string

🔗 Result Handling — Chain Variables

Chain apply-mode variables to the output. Each variable receives the result of the previous one.

matchRegex()

+ Chain another variable

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Related Variables

Same category: String

→ assignParamsToString → charAt → concatenateValues → countWordsInString → endsWith → extractFirstSegment → extractNumber → fromBase64 → indexOf → left → matchAll → matchRegex → omitParamsFromString → padEnd → padStart → pickParamsFromString → replaceAll → replaceAllWithRegex → replaceFirst → right → safeSplit → sanitizeTextAndRemoveHtml → sanitizeTextLite → search → slice → split → startsWith → test → toBase64 → toCamelCase → toJsonString → toKebabCase → toLocaleLowerCase → toLocaleUpperCase → toLowerCase → toNumber → toSnakeCase → toStartCase → toString → toStringRepresentation → toUpperCase → toUpperFirst → trim → trimEnd → trimStart → truncate

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Under the Hood

📜 View Implementation Code

/**
 * Matches the provided string against the given regular expression pattern.
 * 
 * @param {string} data.src - The string to search within.
 * @param {string} data.rex - The regular expression pattern to match in the string.
 * @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 matching.
 * 
 * @returns {string|undefined} The first capture group if present, otherwise the full match. Returns undefined if no match is found or input is invalid.
 *
 * @framework ggLowCodeGTMKit
 */

const matchRegex = function(stringToMatch, regexPattern) {
   if (typeof stringToMatch !== 'string' || typeof regexPattern !== 'string') { 
       return undefined; 
   }
   const match = stringToMatch.match(regexPattern);
   if (match === null) return undefined;
   // Return captured group if exists, otherwise full match
   return match[1] !== undefined ? match[1] : match[0];
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// matchRegex - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(matchRegex(value, data.rex));
// ===============================================================================
// matchRegex(...) – Apply Mode
// ===============================================================================
/*
return function(value, regexPattern) {
  regexPattern = data.rp1 ? data.rex : regexPattern;
  return out(matchRegex(value, regexPattern));
};
*/

🧪 View Test Scenarios (12 tests)

✅ '[example] Extract numbers from string'
✅ Email pattern match
✅ No match found
✅ Word pattern match
✅ '[example] Non-string input returns undefined'
✅ Invalid regex pattern (non-string)
✅ Empty string input
✅ UI-bound mode with static regex
✅ Multiple matches (returns first)
✅ Case-sensitive pattern
✅ '[example] GA cookie CID extraction'
✅ Capture group extraction - Email username only