string-function-exec

StringFunction

This module provides an ability to execute stringified javascript/node.js functions. StringFunction module can basically used to execute any type of javascript's string-compiled routines such as a various of regular, anonymous or arrow - functions.

Note #1 This module can be used with any existing version of node.js and npm.

How to install the module:

By using npmjs.org:

 npm install string-function-exec --save

How to use the string-function-exec module installed:

Parsing JavaScript/Node.JS stringified functions

 
// A string containing "regular" javascript function to be executed
var fn1_s = "function f(alias, args) { return alias + \" \" + JSON.stringify(args); }";
 
console.log(new StringFunction(fn1_s).parse_function("fn1",[1,2,3]));
 
// A string containing "regular" javascript function containing "anonymous" and "arrow" functions
var fn2_s = "function f(alias, args) { var f1 = function (t_param1) { return t_param1; }; \
                                       var f2 = (t_param2, t_args) => { return t_param2 + \" \" + t_args; }; \
                                       return f1(alias) + \" \" + f2(alias, args) + \" \" + JSON.stringify(args); }";
 
console.log(new StringFunction(fn2_s).parse_function("fn2",[10,20,30]));
 
// A string containing "anonymous" javascript function to be executed
var fn3_s = "function (alias, args) { return alias.toString() + \" \" + JSON.stringify(args); }";
 
console.log(new StringFunction(fn3_s).parse_function("fn3",[100,200,300]));
 
// A string containing "arrow" javascript function to be executed
var fn4_s = "(alias, args)=>{ return alias.toString() + \" \" + JSON.stringify(args); }";
 
console.log(new StringFunction(fn4_s).parse_function("fn4",[1000,2000,3000]));
 
// A string containing two nested "arrow" javascript function to be executed
var fn5_s = "(alias, args) => { var f1 = (p1, p2)=>{ return p1 + \" \" + JSON.stringify(p2); }; return f1(alias, args);}";
 
console.log(new StringFunction(fn5_s).parse_function("fn5",[10000,20000,30000]));
 

Stringified JavaScript/Node.JS functions execution

 
// A string containing "regular" javascript function to be executed
var fn1_s = "function f(alias, args) { return alias + \" \" + JSON.stringify(args); }";
 
console.log(new StringFunction(fn1_s).execute("fn1",[1,2,3]));
 
// A string containing "regular" javascript function containing "anonymous" and "arrow" functions
var fn2_s = "function f(alias, args) { var f1 = function (t_param1) { return t_param1; }; \
                                       var f2 = (t_param2, t_args) => { return t_param2 + \" \" + t_args; }; \
                                       return f1(alias) + \" \" + f2(alias, args) + \" \" + JSON.stringify(args); }";
 
console.log(new StringFunction(fn2_s).execute("fn2",[10,20,30]));
 
// A string containing "anonymous" javascript function to be executed
var fn3_s = "function (alias, args) { return alias.toString() + \" \" + JSON.stringify(args); }";
 
console.log(new StringFunction(fn3_s).execute("fn3",[100,200,300]));
 
// A string containing "arrow" javascript function to be executed
var fn4_s = "(alias, args)=>{ return alias.toString() + \" \" + JSON.stringify(args); }";
 
console.log(new StringFunction(fn4_s).execute("fn4",[1000,2000,3000]));
 
// A string containing two nested "arrow" javascript function to be executed
var fn5_s = "(alias, args) => { var f1 = (p1, p2)=>{ return p1 + \" \" + JSON.stringify(p2); }; return f1(alias, args);}";
 
console.log(new StringFunction(fn5_s).execute("fn5",[10000,20000,30000]));
 

Constructor

.StringFunction

.StringFunction(StringFunc)

StringFunc - an input string containing function's code,

Methods

.parse_function(Args)

parses a stringified javascript/node.js function and returns the compiled function's code ready to be executed by using generic javascript's global.eval function. Method parse_function accepts an array of arguments Args of any time for a javascript's function being executed.

.execute( arguments )

console.log(new StringFunction(fn1_s).execute("fn1",[1,2,3])); compiles and executes javascript/node.js function passed as a parameter of string type to the StringFunction object's constructor. The method execute accepts the list of arguments passed to a stringified function being executed. This method normally returns a value passed at the end of stringified function execution or an specific code if a compilation or execution error has occured.

Sample

 
'use strict'
 
var StringFunction = require('string-function-exec');
 
var sf_obj = new StringFunction("function test(p1, p2) { return p1 + p2; }");
 
var compiled_func = sf_obj.parse_function(10, 20);
var result = sf_obj.execute(10,20);
 
if (compiled_func.length > 0 && result != undefined) {
    console.log("compiled function = " + 
        compiled_func + "\n" + "return value = " + JSON.stringify(result));
}
 
process.exit(0);
 

Conclusion

That's All Folks :)

Author

Arthur V. Ratz @ Epsilon Software Development Labs.