Replicating entities in TypeScript

Question

Replicating entities in TypeScript

I am currently developing an Angular 2 application using TypeScript. In a User Management component, I have implemented a table that displays all the users in my system.

When a user is clicked on within the table, a form appears with their complete set of properties for editing. The selection of a user triggers the following event:

 onUserSelected(event) {
        var selectedId = event.data.id;
        this.selectedUser = this.users.filter(user => user.id === selectedId)[0]
    }

However, I encountered an issue where when the selectedUser is edited, the changes reflect directly in the table as well, which is not ideal from a user experience standpoint. My attempt to create a copy of the user by implementing a clone function did not resolve the issue - see code below:

 clone() {
        var cloned = new User(this.id, this.login, this.name, this.surname, this.phone);
        return cloned;
    }

It seems like there might be a better way to handle this situation in Angular 2. Any suggestions or recommendations would be greatly appreciated.

angular typescript

Answer 1

Answer №1

Consider utilizing

this.newUser = Object.assign({}, existingObject);

As pointed out by @JSExperts, keep in mind that this method is suitable for copying shallow objects only; for deep object copying, explore alternative solutions.

Answer 2

Consider utilizing

this.newUser = Object.assign({}, existingObject);

As pointed out by @JSExperts, keep in mind that this method is suitable for copying shallow objects only; for deep object copying, explore alternative solutions.

Answer 3

Answer №2

For working with objects and arrays, consider utilizing lodash:

https://lodash.com/docs#cloneDeep

Lodash is highly recommended for a wide range of object and array manipulations.

Answer 4

For working with objects and arrays, consider utilizing lodash:

https://lodash.com/docs#cloneDeep

Lodash is highly recommended for a wide range of object and array manipulations.

Answer 5

Answer №3

One approach is to bind the editor form to a new User object named editUser, instead of directly using the selectedUser variable that points to an element in your user collection. When the onUserSelected(event) function is triggered, you can set the editUser by copying over the mutable properties from the selected user object. Upon submitting the edit form with (ngSubmit)="editSubmit()", you can update the original selected user object with the edited properties.

This could look something like this:

editUser: User = new User();
selectedId: number;
selectedUser: User;

onUserSelected(event) {
    this.selectedId = event.data.id;
    this.selectedUser = this.users.filter(user => user.id === this.selectedId)[0];
    this.editUser = this.cloneAttributes(this.selectedUser);
}

editSubmit(event) {
    this.selectedUser = this.cloneAttributes(this.editUser);
}

cloneAttributes(obj: any) {
    return Object.assign({}, obj);
}

Keep in mind that the current implementation of simpleClone() may not work for deep cloning scenarios where User objects contain references to other objects. If needed, consider creating a proper deep cloning function for more complex data structures.

Answer 6

One approach is to bind the editor form to a new User object named editUser, instead of directly using the selectedUser variable that points to an element in your user collection. When the onUserSelected(event) function is triggered, you can set the editUser by copying over the mutable properties from the selected user object. Upon submitting the edit form with (ngSubmit)="editSubmit()", you can update the original selected user object with the edited properties.

This could look something like this:

editUser: User = new User();
selectedId: number;
selectedUser: User;

onUserSelected(event) {
    this.selectedId = event.data.id;
    this.selectedUser = this.users.filter(user => user.id === this.selectedId)[0];
    this.editUser = this.cloneAttributes(this.selectedUser);
}

editSubmit(event) {
    this.selectedUser = this.cloneAttributes(this.editUser);
}

cloneAttributes(obj: any) {
    return Object.assign({}, obj);
}

Keep in mind that the current implementation of simpleClone() may not work for deep cloning scenarios where User objects contain references to other objects. If needed, consider creating a proper deep cloning function for more complex data structures.

Replicating entities in TypeScript

Answer №1

Answer №2

Answer №3

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