Could you please support using symbol value for ":key" field(when using v-for doing list rendering)?

[gitby15]

What problem does this feature solve?

When I using "v-for" to render an list, every "instance" in the list has an "id",
I would like to use a symbol type to express my "id" , and fill my "id" into ":key".
Every thing is OK until my "id" has duplicate（Example: push same "instance" into list twice by mistake）

In function "checkDuplicateKeys", when Vue detected duplicate key, it will log a warning, the warnning code is :

"warn(
            ("Duplicate keys detected: '"   key   "'. This may cause an update error."),
            vnode.context
          );"

When the file "key" is symbol type, the browser will throw an error because jointing a symbol value with string, and then byebye my application.

I check the document, It didn't tell us that we can use an symbol into key, so I think it is not a bug.
So, could you please support symbol type in list rendering?

What does the proposed API look like?

• {{item.content}}

<script> import ... export default Vue.extend({ data(){ return { list:[{id:Symbol('id), content:'a'},{id:Symbol('id), content:'b'},{id:Symbol('id), content:'c'},{id:Symbol('id), content:'d'}] } } }) </script>

[posva]

It works fine: http://jsfiddle.net/jgbsjoxs/
Please, next time consider using the forum, the Discord server or StackOverflow for questions first. But feel free to come back and open an issue if it turns out to be a bug 🙂

[mpawelski]

It was also not clear for me that symbols as keys are supported. Untill I searched github and found it's explicitly supported since v2.5.12.

I think documentation should be updated and say that key can be number | string | symbol. Also console warning [Vue warn]: Avoid using non-primitive value as key, use string/number value instead. should be changed to [Vue warn]: Avoid using non-primitive value as key, use string/number/symbol value instead.

Then it will be more obvious that this is supported, and not just "happens to work by accident".

[posva]

@mpawelski could you open a pull request at vuejs/vuejs.org please if there isn't one already?