Class: Function

CalcEngine.Functions.Function

Hierarchy

• Function

  ↳ AsyncFunction

Table of contents

Constructors

• constructor

Properties

• maxArgs
• minArgs
• name
• typeName

Methods

• acceptsArray
• acceptsError
• acceptsMissingArgument
• acceptsReference
• description
• evaluate
• findBranchArgument
• findTestArgument
• isBranch
• isContextSensitive
• isVolatile

Constructors

constructor

• new Function(name, minArgs?, maxArgs?, functionDescription?)

Represents an abstract base class for defining functions.

example

class FactorialFunction extends GC.Spread.CalcEngine.Functions.Function {
    constructor () {
        super('FACTORIAL', 1, 1, {
            description: "Function to calculate the Fibonacci number.",
            parameters: [{ name: 'n' }]
        });
    }
    evaluate (n) {
        var fib = [0, 1];
        for (var i = 2; i <= n; i++) {
          fib[i] = fib[i - 1] + fib[i - 2];
        }
        return fib[n];
    }
}
spread.addCustomFunction(new FactorialFunction());
spread.getActiveSheet().setFormula(0, 0, '=FACTORIAL(10)');

Parameters

Name	Type	Description
name	string	The name of the function.
minArgs?	number	-
maxArgs?	number	-
functionDescription?	IFunctionDescription	-

Properties

maxArgs

• maxArgs: number

Represents the maximum number of arguments for the function.

---

minArgs

• minArgs: number

Represents the minimum number of arguments for the function.

---

name

• name: string

Represents the name of the function.

---

typeName

• typeName: string

Represents the type name string used for supporting serialization.

Methods

acceptsArray

▸ acceptsArray(argIndex): boolean

Determines whether the function accepts array values for the specified argument.

function

Parameters

Name	Type	Description
argIndex	number	Index of the argument.

Returns

boolean

true if the function accepts array values for the specified argument; otherwise, false.

---

acceptsError

▸ acceptsError(argIndex): boolean

Indicates whether the function can process Error values.

function

Parameters

Name	Type	Description
argIndex	number	Index of the argument.

Returns

boolean

true if the function can process Error values for the specified argument; otherwise, false.

---

acceptsMissingArgument

▸ acceptsMissingArgument(argIndex): boolean

Indicates whether the Evaluate method can process missing arguments.

Parameters

Name	Type	Description
argIndex	number	Index of the argument

Returns

boolean

true if the Evaluate method can process missing arguments; otherwise, false.

---

acceptsReference

▸ acceptsReference(argIndex): boolean

Determines whether the function accepts Reference values for the specified argument.

function

Parameters

Name	Type	Description
argIndex	number	Index of the argument.

Returns

boolean

true if the function accepts Reference values for the specified argument; otherwise, false.

---

description

▸ description(): IFunctionDescription

Returns the description of the function.

function

Returns

IFunctionDescription

The description of the function.

---

evaluate

▸ evaluate(...args): any

Returns the result of the function applied to the arguments.

Parameters

Name	Type	Description
...args	any	Arguments for the function evaluation

Returns

any

The result of the function applied to the arguments.

---

findBranchArgument

▸ findBranchArgument(test): number

Finds the branch argument.

example

function EqualsFunction() {
    this.name = 'Equals';
    this.maxArgs = 3;
    this.minArgs = 3;
}
EqualsFunction.prototype = new GC.Spread.CalcEngine.Functions.Function();
EqualsFunction.prototype.evaluate = function(logicalTest, valueIfTrue, valueIfFalse) {
    return logicalTest ? valueIfTrue : valueIfFalse;
}
EqualsFunction.prototype.isBranch = function() {
    return true;
}
EqualsFunction.prototype.findTestArgument = function() {
    return 0;
}
EqualsFunction.prototype.findBranchArgument = function(logicalTestResult) {
    if (logicalTestResult === true) {
        return 1;
    }
    return 2;
}
var equalsFunction = new EqualsFunction();
var spread = GC.Spread.Sheets.findControl("ss") || GC.Spread.Sheets.findControl("sampleDiv");
spread.addCustomFunction(equalsFunction);

Parameters

Name	Type	Description
test	any	The test.

Returns

number

Indicates the index of the argument that would be treated as the branch condition.

---

findTestArgument

▸ findTestArgument(): number

Finds the test argument when this function is branched.

example

function EqualsFunction() {
    this.name = 'Equals';
    this.maxArgs = 3;
    this.minArgs = 3;
}
EqualsFunction.prototype = new GC.Spread.CalcEngine.Functions.Function();
EqualsFunction.prototype.evaluate = function(logicalTest, valueIfTrue, valueIfFalse) {
    return logicalTest ? valueIfTrue : valueIfFalse;
}
EqualsFunction.prototype.isBranch = function() {
    return true;
}
EqualsFunction.prototype.findTestArgument = function() {
    return 0;
}
EqualsFunction.prototype.findBranchArgument = function(logicalTestResult) {
    if (logicalTestResult === true) {
        return 1;
    }
    return 2;
}
var equalsFunction = new EqualsFunction();
var spread = GC.Spread.Sheets.findControl("ss") || GC.Spread.Sheets.findControl("sampleDiv");
spread.addCustomFunction(equalsFunction);

Returns

number

Indicates the index of the argument that would be treated as the test condition.

---

isBranch

▸ isBranch(): boolean

Gets a value that indicates whether this function is branched by arguments as conditional. Used in conjunction with the findBranchArgument and findTestArgument.

example

function EqualsFunction() {
    this.name = 'Equals';
    this.maxArgs = 3;
    this.minArgs = 3;
}
EqualsFunction.prototype = new GC.Spread.CalcEngine.Functions.Function();
EqualsFunction.prototype.evaluate = function(logicalTest, valueIfTrue, valueIfFalse) {
    return logicalTest ? valueIfTrue : valueIfFalse;
}
EqualsFunction.prototype.isBranch = function() {
    return true;
}
EqualsFunction.prototype.findTestArgument = function() {
    return 0;
}
EqualsFunction.prototype.findBranchArgument = function(logicalTestResult) {
    if (logicalTestResult === true) {
        return 1;
    }
    return 2;
}
var equalsFunction = new EqualsFunction();
var spread = GC.Spread.Sheets.findControl("ss") || GC.Spread.Sheets.findControl("sampleDiv");
spread.addCustomFunction(equalsFunction);

Returns

boolean

true if this instance is branched; otherwise, false.

---

isContextSensitive

▸ isContextSensitive(): boolean

Determines whether the evaluation of the function is dependent on the context in which the evaluation occurs.

example

class ContextFunction extends GC.Spread.CalcEngine.Functions.Function {
    constructor () {
        super('CONTEXT', 0, 0);
    }
    isContextSensitive () {
        return true;
    }
    evaluate (context) {
        return context.row + "/" + context.column;
    }
}
spread.addCustomFunction(new ContextFunction());
spread.getActiveSheet().setFormula(0, 0, '=CONTEXT()');

Returns

boolean

true if the evaluation of the function is dependent on the context; otherwise, false.

---

isVolatile

▸ isVolatile(): boolean

Determines whether the function is volatile while it is being evaluated. The volatile function is re-evaluated when any cell in the workbook is changed.

example

class RandColorFunction extends GC.Spread.CalcEngine.Functions.Function {
    constructor () {
        super('RANDCOLOR', 0, 0);
    }
    isVolatile () {
        return true;
    }
    evaluate () {
        return "#" + Math.floor(Math.random() * 16777215).toString(16);
    }
}
spread.addCustomFunction(new RandColorFunction());
spread.getActiveSheet().setFormula(0, 0, '=RANDCOLOR()');

Returns

boolean

true if the function is volatile; otherwise, false.