CODEWITHSUNDEEP
angularjstypescript
klmuralimohan
klmuralimohan

Reputation: 931

Typescript - data is not accessible inside the functuon

I have created recursive (rec) function inside setBinary method in typescript. But some reason copyColumns data is not accessible inside the recursive function in typescript but outside rec function working fine. What is wrong in my code.

while running the console.log(this.copyColummns); It gives undefined.

copyNodeHandler ( column, node ) {
            this.copyHeaders = [];
            this.copyHeadersDeepCopy = [];
            for ( let i = 0; i < node[ 0 ].values.length; i++ ) {
                this.copyHeaders.push(node[ 0 ].values[ i ].parameterId)
            }
            this.copyColumns = node;
        }

setBinary(rowId, vId, data) {          


console.log(this.copyColumns); // working fine

    let rec = function (pri, pvi) {
        console.log(pri + '' + pvi);
        console.log(this.copyColumns); // Not working returns undefined.
        let latest = [];           
        if (this.copyColumns[pri]) {
            this.copyColumns[pri].values[pvi].active = true;          

           let  x = this.copyColumns[pri].values[pvi]
            rec(x.pri, x.pvi)
        }
    };


    rec(data.pri, data.pvi)

}

Upvotes: 1

Views: 64

Answers (1)

Frank Adrian
Frank Adrian

Reputation: 1234

You are creating a new function which creates a new scope in javascript.

You can either use arrow functions, which preserves the scope of the function it is defined in, or you need to bind(this) to your function.

Approach 1:

           // arrow function
let rec = (pri, pvi) => {
    console.log(pri + '' + pvi);
    console.log(this.copyColumns); // Now this.copyColumns will be the same as outside this function
    let latest = [];           
    if (this.copyColumns[pri]) {
        this.copyColumns[pri].values[pvi].active = true;          

       let  x = this.copyColumns[pri].values[pvi]
        rec(x.pri, x.pvi)
    }
};

Approach 2:

let rec = function (pri, pvi) {
    console.log(pri + '' + pvi);
    console.log(this.copyColumns); // Not working returns undefined.
    let latest = [];           
    if (this.copyColumns[pri]) {
        this.copyColumns[pri].values[pvi].active = true;          

       let  x = this.copyColumns[pri].values[pvi]
        rec(x.pri, x.pvi)
    }
// bind this to the function
}.bind(this);

Upvotes: 1

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