What is the most effective way to assign req.body values to an attribute of a class?

Question

What is the most effective way to assign req.body values to an attribute of a class?

I am currently working on a class that serves as a controller to execute a method when called from a route. In the list method, I am trying to assign a value to my dataStore attribute without specifying a particular type since I am unsure of what type it should be. The object that is supposed to provide this value is expected to come from req.body.

This implementation is in TypeScript and the requests are being transmitted through Postman.

class RentController{
    private dataStore:any; 

    public search(req:Request, res:Response){
        this.dataStore= req.body; 
        res.send(this.dataStore);
    }
}

Here is the request sent via Postman
Here is the response received via Postman

The error message that I encounter reads:

TypeError: Cannot set property 'dataStore' of undefined

javascript typescript express frontend

Answer 1

Answer №1

Your code is causing confusion for the compiler because you are using this outside of any defined scope. To resolve this issue, make sure to use

RentController.dataStore = req.body;

instead. This assigns the value of req.body to the dataStore attribute of RentController.

Avoid using this in situations like this as it only adds complexity. Instead, if you need to use the parameter, consider using req.dataStore or res.dataStore, but steer clear of using this.

Answer 2

Your code is causing confusion for the compiler because you are using this outside of any defined scope. To resolve this issue, make sure to use

RentController.dataStore = req.body;

instead. This assigns the value of req.body to the dataStore attribute of RentController.

Avoid using this in situations like this as it only adds complexity. Instead, if you need to use the parameter, consider using req.dataStore or res.dataStore, but steer clear of using this.

Answer 3

Answer №2

Your class members are not being initialized with any default value, hence they are currently undefined.

To resolve this issue, try assigning a default value and then check the result to see that value displayed.

class RentController{
    private dataStore:any = {value: 1}; 

    public search(req:Request, res:Response){
        this.dataStore= req.body; 
        res.send(this.dataStore);
    }
}

Answer 4

Your class members are not being initialized with any default value, hence they are currently undefined.

To resolve this issue, try assigning a default value and then check the result to see that value displayed.

class RentController{
    private dataStore:any = {value: 1}; 

    public search(req:Request, res:Response){
        this.dataStore= req.body; 
        res.send(this.dataStore);
    }
}

What is the most effective way to assign req.body values to an attribute of a class?

Answer №1

Answer №2

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