CODEWITHSUNDEEP
dartflutter
Denis Ramdan
Denis Ramdan

Reputation: 1954

Flutter Edit List Item

I have a question in my flutter dart script, this my script:

List<ReplyTile> replytile = new List<ReplyTile>();

replytile.add(
    new ReplyTile(
        member_photo: "photo",
        member_id: "001",
        date: "01-01-2018",
        member_name: "Denis",
        id: "001",
        text: "hallo.."
    )
);

My question is: how to EDIT items 'member_name' on List with id = 001.. ?

Upvotes: 12

Views: 41468

Answers (5)

Yogesh Alai
Yogesh Alai

Reputation: 179

Suppose you have a list like

List list =[{id=11,name=aaaa},{id=12,name=bbbb},{id=13,name=ccc}];

We have to find index of that object from list.

var data ={id=12,name=bbbb};
int index = list.indexof(data);

Now, you can update list

list[index] = {id=12,name=fffffff}

Upvotes: 1

Shadab Hashmi
Shadab Hashmi

Reputation: 387

Below is the code to update a single item of list using the index. You can simple create an extension function for the same.

extension ListUpdate<T> on List<T> {
  List<T> update(int pos, T t) {
    List<T> list = [];
    list.add(t);
    replaceRange(pos, pos + 1, list);
    return this;
  }
}

And use it like below to replace an item.

replytile.update(
    5, new ReplyTile(
        member_photo: "photo",
        member_id: "001",
        date: "01-01-2018",
        member_name: "Denis",
        id: "001",
        text: "hallo.."
    )
);

Upvotes: 8

Rao Saqib
Rao Saqib

Reputation: 9

Suppose you have a list like

List list =[{id=11,name=aaaa},{id=12,name=bbbb},{id=13,name=ccc}];

And now you have just index data which will be update Suppose

var data ={id=12,name=bbbb};
int index = list.indexof(data);

Now Update list as

list.insert(index,{id=12,name=fffffff});

Now output is

print(list);
// [{id=11,name=aaaa},{id=12,name=fffffff},{id=13,name=ccc}];

Upvotes: 0

Jacob Phillips
Jacob Phillips

Reputation: 9274

This assumes a ReplyTile is a widget, if it is not, you don't need the setState calls.

If you can guarantee the item is in the list, use:

final tile = replytile.firstWhere((item) => item.id == '001');
setState(() => tile.member_name = 'New name');

If the item is not found, an exception is thrown. To guard against that, use:

final tile = replytile.firstWhere((item) => item.id == '001', orElse: () => null);
if (tile != null) setState(() => tile.member_name = 'New name');

Upvotes: 18

boformer
boformer

Reputation: 30123

Widgets should be immutable (with final fields) and not meant to be manipulated by a parent widget.

Usually you are not supposed to store a list of widgets. Widgets should be rebuilt from scratch whenever the build method is called.

Instead, store the displayed data in a separate data structure (e.g. create a class ReplyTileData) with mutable fields. This data structure should be stored in your State class.

In the build method, read the data and instantiate your ReplyTile widgets with the current data.

When you want to modify the data, surround the modifying code with setState. This will trigger a complete rebuild (build called again).

Upvotes: 2

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