Creating a variable name from a string using a function

Question

Creating a variable name from a string using a function

I am creating a log to keep track of the functions that are called. One specific function I am using is

record_activity( function_name );

I find it tedious to manually add this at the beginning of every function I want to monitor. Currently, my functions are structured like:

Object.Key.Func = function() { ... }

I have come up with a solution which seems to be working, but I am unsure about its implications:

function sub ( variable, func ) {
    var temp_func = function ( args ) {
        record_activity( variable );
        return func.apply(this,arguments);
    }
    eval( variable + ' = ' + temp_func );
}

sub( 'Object.Key.Func', function (name) { alert('hi ' + name) } );
Object.Key.Func('test');

If there is a method to achieve this without using eval, I would greatly appreciate it.

Thanks

javascript string variables variable-assignment

Answer 1

Answer №1

To monitor the behavior of specific functions, you can implement wrapper functions for each one. Below is a snippet of code that demonstrates how to achieve this:

var counter = {};
// This function records activity for a specified function.
function record_activity (f, func_name, args) {
    counter[func_name] = counter[func_name]===undefined ? 1 : counter[func_name]+1;
}

// Define an object with functions to track: obj.foo and obj.bar
var obj = {
    a: 3,
    foo: function () {
        console.log("foo");
    },
    bar: function (b) {
        console.log("bar", this.a, b);
    }
};

// Create wrapper functions for tracking function calls
function create_func (f, func_name) {
    return function () {
        record_activity(f, func_name, arguments);
        f.apply(obj, arguments);
    };
}
for(var prop in obj) {
    if (typeof obj[prop] === 'function') {
        // Wrap the original function with the tracking functionality
        obj[prop] = create_func(obj[prop], prop);
    }
};

// Test the wrapped functions
for (var i = 0; i < 3; i++) {
    obj.foo();
};
for (var i = 0; i < 10; i++) {
    obj.bar(i);
};

console.log(counter);

Answer 2

To monitor the behavior of specific functions, you can implement wrapper functions for each one. Below is a snippet of code that demonstrates how to achieve this:

var counter = {};
// This function records activity for a specified function.
function record_activity (f, func_name, args) {
    counter[func_name] = counter[func_name]===undefined ? 1 : counter[func_name]+1;
}

// Define an object with functions to track: obj.foo and obj.bar
var obj = {
    a: 3,
    foo: function () {
        console.log("foo");
    },
    bar: function (b) {
        console.log("bar", this.a, b);
    }
};

// Create wrapper functions for tracking function calls
function create_func (f, func_name) {
    return function () {
        record_activity(f, func_name, arguments);
        f.apply(obj, arguments);
    };
}
for(var prop in obj) {
    if (typeof obj[prop] === 'function') {
        // Wrap the original function with the tracking functionality
        obj[prop] = create_func(obj[prop], prop);
    }
};

// Test the wrapped functions
for (var i = 0; i < 3; i++) {
    obj.foo();
};
for (var i = 0; i < 10; i++) {
    obj.bar(i);
};

console.log(counter);

Creating a variable name from a string using a function

Answer №1

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