在回调中设置全局变量

Question

Tried to simplify my code to show my problem.

var rp = require('request-promise');
var ids = [];

runmyFunction();
runmyFunction();

function runmyFunction() {
    var id = 5;
    console.log("runmyFunc:  "+ids);
    if (ids.indexOf(id)==-1){
       myFunction(id);
    }
}

function myFunction(id) {
    var options = {
        uri: 'someURI'
        , headers: {
            'User-Agent': 'Request-Promise'
        }
        , json: true
    };
    rp(options)
        .then(function (response) {
            ids.push(5);
            console.log("myFunc: "+ids);
        })
        .catch(function (err) {
           console.log(err);
        });
}

Basically I have this function runmyFunction , which should only execute myFunction if there is not the id 12345 in it. So if I run it 10 times and the 11th the id 12345 is returned, it should stop running the function. The problem is that the id never gets pushed in the array even if the request succeeded.

Similar problems had something to do with the request being asynchronous. Is this the cause in my code as well?

//edit I played around with it and edited the code. Current code logs this into the console:

runmyFunc:  
runmyFunc:  
myFunc:5
myFunc:5,5

So it is because it is asynchronus. Any ideas to avoid that?

Answer 1

not sure but i think your problem will be solved by using .bind() maybe help :

var rp = require('request-promise');
var ids = [];


function runmyFunction() {
    if (ids.indexOf(12345)==-1){
   myFunction();
   }
}

function myFunction() {
    var options = {
    uri: 'someURI'
    , headers: {
        'User-Agent': 'Request-Promise'
    }
    , json: true
};
rp(options)
    .then(function (response,mids) {
        mids.push(response.data.id);
    }.bind(ids))
    .catch(function (err) {
       console.log(err);
    });
}

Answer 2

Thanks to @Shilly i found a solution by myself by adding another array.

var rp = require('request-promise');

var ids = [];
var idstmp = [];

runmyFunction();
runmyFunction();

function runmyFunction() {
    var id = 5;
    if (ids.indexOf(id) == -1 && idstmp.indexOf(id) == -1) {
        console.log("I was here.");
        idstmp.push(id);
        myFunction(id);
    }
}

function myFunction(id) {
    var options = {
        uri: 'someURI'
        , headers: {
            'User-Agent': 'Request-Promise'
        }
        , json: true
    };
    rp(options)
        .then(function (response) {
            idstmp.splice(idstmp.indexOf(id), 1);
            ids.push(id);
            console.log("myFunc: " + ids);
        })
        .catch(function (err) {
        idstmp.splice(idstmp.indexOf(id), 1);
        });
}

What this does is just adding the ids which are curently 'in use' by the request to another array so it gets block while beeing worked with. It is quite a workaround but works for me.