Debounce a struct map grouped by id-CodePudding

I am trying to figure out if there is a way to debounced a struct map that is group by an id.

Using the following struct for this example:

type Message struct {
    id    int
    attrs []string
}

This is how I am creating the list

messages := []Message{
        Message{
            id:    10,
            attrs: []string{"blah", "foo"},
        },
        Message{
            id:    10,
            attrs: []string{"add", "ddsds"},
        },
        Message{
            id:    11,
            attrs: []string{"foo", "bar"},
        },
        Message{
            id:    12,
            attrs: []string{"xyz"},
        },
    }

And then turning into a map grouped by id:

collections := make(map[int][]Message)

    for _, j := range messages {
        collections[j.id] = append(collections[j.id], j)
    }

This is the main function:

debounced := debounce.New(100 * time.Millisecond)

    for _, messageMap := range collections {
        for _, message := range messageMap {
            debounced(func() {
                fmt.Println("id", message.id, "attrs =>", message.attrs)
            })
        }
    }

    time.Sleep(500 * time.Millisecond)

The output is:

id 12 attrs => [xyz]

This is not correct. And it looks like it just getting the last message.

CodePudding user response：

I got it to work. I just need to wait after the first loop:

debounced := debounce.New(100 * time.Millisecond)

    for _, messageMap := range collections {
        for _, message := range messageMap {
            message := message // Copy the loop var
            debounced(func() {
                fmt.Println("id", message.id, "attrs =>", message.attrs)
            })
        }
        time.Sleep(500 * time.Millisecond)
    }

CodePudding user response：

With the closure you are capturing the loop variable, which is rewritten for every iteration. Capture a copy of it:

for _, message := range messageMap {
            message:=message  // Copy the loop var
            debounced(func() {
                fmt.Println("id", message.id, "attrs =>", message.attrs)
            })
        }