Is there a way to chain functions in JavaScript so when last function in chain is called we take into consideration all function in chain that was specified. Basically what I am trying to do is the same thing express-validator does: Something like this:
check('password').passwordValidator().optional();
I want to be able to call
check('password').passwordValidator();
and
check('password').passwordValidator().optional();
So you're looking for a sort of builder pattern? You can do that like this:
class Foo {
_passwordValidator = false;
_optional = false;
passwordValidator() {
this._passwordValidator = true;
return this;
}
optional() {
this._optional = true;
return this;
}
doThing() {
if (this._optional) { /* ... */ }
if (this._passwordValidator) { /* ... */ }
}
}
const foo = new Foo().passwordValidator().optional();
foo.doThing();
Edit: to more directly answer your question, there is no way to wait to do something until the current chain of method calls is done; you have to call a method like doThing()
in the example to signal that you actually want to do the thing now.
I ended up using what @coolreader18 suggested. That was exactly what I was looking for.
function func(val) {
this._optional = false;
this._check = false;
const doStaff = (message = 'Doing staff') => {
console.log(message);
return;
};
return {
check: function(n) {
this._check = true;
return this;
},
optional: function(n) {
this._check = false;
this._optional = true;
return this;
},
exec: function() {
if (this._check) doStaff();
if (this._optional) doStaff('Maybe not');
}
}
}
func().check().optional().exec();
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