89159fb927
- Create validator.js with validateNumericInput() function
- Validates numeric strings; allows digits, leading minus, single decimal point
- Rejects invalid characters, multiple decimals, misplaced minus signs
- Returns { isValid, value, sanitized } object
- Link validator.js in index.html <head>
- Update CLAUDE.md project structure to include validator.js
48 lines
1.2 KiB
JavaScript
48 lines
1.2 KiB
JavaScript
/**
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* Validates a numeric input string.
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*
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* Allowed characters: digits 0-9, a single decimal point, a leading minus sign.
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* Returns an object with:
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* isValid {boolean} - true when the string represents a well-formed number
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* value {number|null} - parsed numeric value, or null when invalid
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* sanitized {string} - trimmed input string
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*/
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function validateNumericInput(input) {
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var str = String(input).trim();
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var result = { isValid: false, value: null, sanitized: str };
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if (str === '') {
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return result;
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}
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// Reject characters other than digits, decimal point, and minus sign
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if (/[^0-9.\-]/.test(str)) {
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return result;
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}
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// Minus sign is only valid as the very first character
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var minusCount = (str.match(/-/g) || []).length;
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if (minusCount > 1 || (minusCount === 1 && str.charAt(0) !== '-')) {
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return result;
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}
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// Only one decimal point is allowed
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if ((str.match(/\./g) || []).length > 1) {
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return result;
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}
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// A bare '-' or '.' is not a valid number
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if (str === '-' || str === '.') {
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return result;
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}
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var parsed = parseFloat(str);
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if (isNaN(parsed)) {
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return result;
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}
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result.isValid = true;
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result.value = parsed;
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return result;
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}
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