Library provides a Parser class that evaluates excel and mathematical formulas.
A recommended way to install Formula Parser is through NPM using the following command:
$ npm install hot-formula-parser --saveNode.js:
var FormulaParser = require('hot-formula-parser').Parser;
var parser = new FormulaParser();
parser.parse('SUM(1, 6, 7)'); // It returns `Object {error: null, result: 14}`Browser:
<script src="/node_modules/hot-formula-parser/dist/formula-parser.min.js"></script>
<script>
var parser = new formulaParser.Parser();
parser.parse('SUM(1, 6, 7)'); // It returns `Object {error: null, result: 14}`
</script>It supports:
- Any numbers, negative and positive as float or integer;
- Arithmetic operations like
+,-,/,*,%,^; - Logical operations like
AND(),OR(),NOT(),XOR(); - Comparison operations like
=,>,>=,<,<=,<>; - All JavaScript Math constants like
PI(),E(),LN10(),LN2(),LOG10E(),LOG2E(),SQRT1_2(),SQRT2(); - String operations like
&(concatenation eq.parser.parse('-(2&5)');will return-25); - All excel formulas defined in formula.js;
- Relative and absolute cell coordinates like
A1,$A1,A$1,$A$1; - Build-in variables like
TRUE,FALSE,NULL - Custom variables;
- Custom functions/formulas;
- Node and Browser environment.
var parser = new formulaParser.Parser();Parses and evaluates provided expression. It always returns an object with result and error properties. result property
always keep evaluated value. If error occurs error property will be set as:
#ERROR!General error;#DIV/0!Divide by zero error;#NAME?Not recognised function name or variable name;#N/AIndicates that a value is not available to a formula;#NUM!Occurs when formula encounters an invalid number;#VALUE!Occurs when one of formula arguments is of the wrong type.
parser.parse('(1 + 5 + (5 * 10)) / 10'); // returns `Object {error: null, result: 5.6}`
parser.parse('SUM(MY_VAR)'); // returns `Object {error: "#NAME?", result: null}`
parser.parse('1;;1'); // returns `Object {error: "#ERROR!", result: null}`Set predefined variable name which can be visible while parsing formula expression.
parser.setVariable('MY_VARIABLE', 5);
parser.setVariable('fooBar', 10);
parser.parse('(1 + MY_VARIABLE + (5 * fooBar)) / fooBar'); // returns `5.6`Get variable name.
parser.setVariable('fooBar', 10);
parser.getVariable('fooBar'); // returns `10`Set custom function which can be visible while parsing formula expression.
parser.setFunction('ADD_5', function(params) {
return params[0] + 5;
});
parser.setFunction('GET_LETTER', function(params) {
var string = params[0];
var index = params[1] - 1;
return string.charAt(index);
});
parser.parse('SUM(4, ADD_5(1))'); // returns `10`
parser.parse('GET_LETTER("Some string", 3)'); // returns `m`Get custom function.
parser.setFunction('ADD_5', function(params) {
return params[0] + 5;
});
parser.getFunction('ADD_5')([1]); // returns `6`List of all supported formulas function.
require('hot-formula-parser').SUPPORTED_FORMULAS; // An array of formula namesFired while retrieving variable. If variable was defined earlier using setVariable you can overwrite it by this hook.
parser.on('callVariable', function(name, done) {
if (name === 'foo') {
done(Math.PI / 2);
}
});
parser.parse('SUM(SIN(foo), COS(foo))'); // returns `1`Fired while calling function. If function was defined earlier using setFunction you can overwrite it's result by this hook.
You can also use this to override result of build-in formulas.
parser.on('callFunction', function(name, params, done) {
if (name === 'ADD_5') {
done(params[0] + 5);
}
});
parser.parse('ADD_5(3)'); // returns `8`Fired while retrieving cell value by its label (eq: B3, B$3, B$3, $B$3).
parser.on('callCellValue', function(cellCoord, done) {
// using label
if (cellCoord.label === 'B$6') {
done('hello');
}
// or using indexes
if (cellCoord.row.index === 5 && cellCoord.row.isAbsolute && cellCoord.column.index === 1 && !cellCoord.column.isAbsolute) {
done('hello');
}
if (cellCoord.label === 'C6') {
done(0.75);
}
});
parser.parse('B$6'); // returns `"hello"`
parser.parse('B$6&" world"'); // returns `"hello world"`
parser.parse('FISHER(C6)'); // returns `0.9729550745276566`Fired while retrieving cells range value (eq: A1:B3, $A1:B$3, A$1:B$3, $A$1:$B$3).
parser.on('callRangeValue', function(startCellCoord, endCellCoord, done) {
var data = [
[1, 2, 3, 4, 5],
[6, 7, 8, 9, 10],
[11, 12, 13, 14, 15],
[16, 17, 18, 19, 20],
];
var fragment = [];
for (var row = startCellCoord.row.index; row <= endCellCoord.row.index; row++) {
var rowData = data[row];
var colFragment = [];
for (var col = startCellCoord.column.index; col <= endCellCoord.column.index; col++) {
colFragment.push(rowData[col]);
}
fragment.push(colFragment);
}
if (fragment) {
done(fragment);
}
});
parser.parse('JOIN(A1:E2)'); // returns `"1,2,3,4,5,6,7,8,9,10"`
parser.parse('COLUMNS(A1:E2)'); // returns `5`
parser.parse('ROWS(A1:E2)'); // returns `2`
parser.parse('COUNT(A1:E2)'); // returns `10`
parser.parse('COUNTIF(A1:E2, ">5")'); // returns `5`Please see CONTRIBUTING.md.
To see the list of recent changes, see Releases section.
The MIT License (see the LICENSE file for the full text).
You can contact us at [email protected].