Message editing: attach message as reply to other message via Edit form

[MurzNN]

Very often users forgot to select "Reply" when answering to message, and sends new message as new "thread". For fix this they copy-paste message text, send as new "Reply" message, and delete original message.

For simplify this correction task, will be good to have ability for attach already sent message to other message as reply, via Edit form.

[jtagcat]

UI/UX suggestion on how to do this: When user is editing a message, clicking on a reply (currently does nothing while editing) makes the current message a reply.

We also need to think about disengaging a reply (accidentally replied, when meant to send a non-reply).
For this, while editing, an X button should appear on the reply (like on link previews).

Problem is, that X might be misinterpreted as 'cancel editing'. Instead of using the X icon, I'd use the symbol, but with something to indicate, that it's for unlinking (I have seen it before, there's something happening in the middle of the chain, a zap or something).

[jtagcat]

Related element-hq/element-web#2349 (If implementing this, consider that in the future, one should be able to move messages in and out of threads. Make it modular and make the next person's life easier.)

The best way to implement this is probably a 'hidden head tag', what says 'this message is attached to (reply of) message id x, in thread y'.

[MadLittleMods]

API-wise, is it even possible to add m.in_reply_to relation after the fact? I am unable to get it working but perhaps it's more of an Element bug vs an API problem.

Related MSC discussion: matrix-org/matrix-spec-proposals#2676 (comment)

Original events:

{
  "type": "m.room.message",
  "content": {
    "msgtype": "m.text",
    "body": "Reply to this message"
  },
  "sender": "@madlittlemods:matrix.org",
  "event_id": "$ensh3G0vNNxYR6tTkR4D3K0RHzJteaGZerkd-GQIWd8",
  "room_id": "!vaRuaHMtoPkUtcRtCV:matrix.org"
}

{
  "type": "m.room.message",
  "content": {
    "msgtype": "m.text",
    "body": "foo"
  },
  "sender": "@madlittlemods:matrix.org",
  "event_id": "$Bl7NMSBwW-YSjfnpvd_f5ET2bUr_M4nk4315Q-89ZzQ",
  "room_id": "!vaRuaHMtoPkUtcRtCV:matrix.org"
}

And here is what the timeline looks like before any edits:

For reference:

What does a normal message look like with a `m.in_reply_to`

{
  "type": "m.room.message",
  "content": {
    "msgtype": "m.text",
    "body": "> <@madlittlemods:matrix.org> Reply to this message\n\nfoo",
    "format": "org.matrix.custom.html",
    "formatted_body": "<mx-reply><blockquote><a href=\"https://matrix.to/#/!vaRuaHMtoPkUtcRtCV:matrix.org/$BNJlsM_mfjrvzDMbJ7TUp_YZHeGGRYkIFulQXGp_aJs?via=matrix.org&via=gitter.im&via=vector.modular.im\">In reply to</a> <a href=\"https://matrix.to/#/@madlittlemods:matrix.org\">@madlittlemods:matrix.org</a><br>Reply to this message</blockquote></mx-reply>foo",
    "m.relates_to": {
      "m.in_reply_to": {
        "event_id": "$BNJlsM_mfjrvzDMbJ7TUp_YZHeGGRYkIFulQXGp_aJs"
      }
    }
  },
  "sender": "@madlittlemods:matrix.org",
  "event_id": "$xz3ODvwgG7pKolVelsLI33zgFK0tXTa904-cwwTb6Ck",
  "room_id": "!vaRuaHMtoPkUtcRtCV:matrix.org"
}

What does a edited message look like with a `m.in_reply_to`

{
  "type": "m.room.message",
  "content": {
    "m.new_content": {
      "msgtype": "m.text",
      "body": "foo bar",
      "format": "org.matrix.custom.html",
      "formatted_body": "foo bar"
    },
    "m.relates_to": {
      "rel_type": "m.replace",
      "event_id": "$xz3ODvwgG7pKolVelsLI33zgFK0tXTa904-cwwTb6Ck"
    },
    "msgtype": "m.text",
    "body": "> <@madlittlemods:matrix.org> Reply to this message\n\n * foo bar",
    "format": "org.matrix.custom.html",
    "formatted_body": "<mx-reply><blockquote><a href=\"https://matrix.to/#/!vaRuaHMtoPkUtcRtCV:matrix.org/$BNJlsM_mfjrvzDMbJ7TUp_YZHeGGRYkIFulQXGp_aJs?via=matrix.org&amp;via=gitter.im&amp;via=vector.modular.im\">In reply to</a> <a href=\"https://matrix.to/#/@madlittlemods:matrix.org\">@madlittlemods:matrix.org</a><br>Reply to this message</blockquote></mx-reply> * foo bar"
  },
  "sender": "@madlittlemods:matrix.org",
  "event_id": "$l246fF0IBQNLqkVWoGcXhF8tLops024pWMUJDAI_2_Y",
  "room_id": "!vaRuaHMtoPkUtcRtCV:matrix.org"
}

Edit message to just add the m.in_reply_to relation

{
  "type": "m.room.message",
  "content": {
    "body": " * foo",
    "msgtype": "m.text",
    "m.new_content": {
      "body": "foo",
      "msgtype": "m.text"
    },
    "m.relates_to": {
      "rel_type": "m.replace",
      "event_id": "$Bl7NMSBwW-YSjfnpvd_f5ET2bUr_M4nk4315Q-89ZzQ",
      "m.in_reply_to": {
        "event_id": "$ensh3G0vNNxYR6tTkR4D3K0RHzJteaGZerkd-GQIWd8"
      }
    }
  }
}

Results in:

A weird reply artifact is added to the bottom of the timeline and nothing is changed on the original message.

Edit message with m.in_reply_to and the fallback text

{
  "type": "m.room.message",
  "content": {
    "m.new_content": {
      "msgtype": "m.text",
      "body": "foo",
      "format": "org.matrix.custom.html",
      "formatted_body": "foo"
    },
    "m.relates_to": {
      "rel_type": "m.replace",
      "event_id": "$Bl7NMSBwW-YSjfnpvd_f5ET2bUr_M4nk4315Q-89ZzQ",
      "m.in_reply_to": {
        "event_id": "$ensh3G0vNNxYR6tTkR4D3K0RHzJteaGZerkd-GQIWd8"
      }
    },
    "msgtype": "m.text",
    "body": "> <@madlittlemods:matrix.org> Reply to this message\n\n * foo",
    "format": "org.matrix.custom.html",
    "formatted_body": "<mx-reply><blockquote><a href=\"https://matrix.to/#/!vaRuaHMtoPkUtcRtCV:matrix.org/$ensh3G0vNNxYR6tTkR4D3K0RHzJteaGZerkd-GQIWd8?via=matrix.org&amp;via=gitter.im&amp;via=vector.modular.im\">In reply to</a> <a href=\"https://matrix.to/#/@madlittlemods:matrix.org\">@madlittlemods:matrix.org</a><br>Reply to this message</blockquote></mx-reply> * foo"
  }
}

Results in (same thing):

Same thing, a weird reply artifact is added to the bottom of the timeline and nothing is changed on the original message.

Edit message with m.in_reply_to, fallback text, and fallback in the m.new_content

This is a bit taboo, see element-hq/element-web#13811

{
  "type": "m.room.message",
  "content": {
    "m.new_content": {
      "msgtype": "m.text",
      "body": "> <@madlittlemods:matrix.org> Reply to this message\n\n foo",
      "format": "org.matrix.custom.html",
      "formatted_body": "<mx-reply><blockquote><a href=\"https://matrix.to/#/!vaRuaHMtoPkUtcRtCV:matrix.org/$ensh3G0vNNxYR6tTkR4D3K0RHzJteaGZerkd-GQIWd8?via=matrix.org&amp;via=gitter.im&amp;via=vector.modular.im\">In reply to</a> <a href=\"https://matrix.to/#/@madlittlemods:matrix.org\">@madlittlemods:matrix.org</a><br>Reply to this message</blockquote></mx-reply> foo"
    },
    "m.relates_to": {
      "rel_type": "m.replace",
      "event_id": "$Bl7NMSBwW-YSjfnpvd_f5ET2bUr_M4nk4315Q-89ZzQ",
      "m.in_reply_to": {
        "event_id": "$ensh3G0vNNxYR6tTkR4D3K0RHzJteaGZerkd-GQIWd8"
      }
    },
    "msgtype": "m.text",
    "body": "> <@madlittlemods:matrix.org> Reply to this message\n\n * foo",
    "format": "org.matrix.custom.html",
    "formatted_body": "<mx-reply><blockquote><a href=\"https://matrix.to/#/!vaRuaHMtoPkUtcRtCV:matrix.org/$ensh3G0vNNxYR6tTkR4D3K0RHzJteaGZerkd-GQIWd8?via=matrix.org&amp;via=gitter.im&amp;via=vector.modular.im\">In reply to</a> <a href=\"https://matrix.to/#/@madlittlemods:matrix.org\">@madlittlemods:matrix.org</a><br>Reply to this message</blockquote></mx-reply> * foo"
  }
}

Results in:

Something better and closer; an off-styled reply blockquote is added to the original message but it still adds the extra artifact reply blockquote at the bottom of the timeline.

---

Related MSC's

• Add rich replies matrix-org/matrix-spec-proposals#1617
• MSC2674: Event Relationships matrix-org/matrix-spec-proposals#2674
• MSC1767: Extensible event types & fallback in Matrix (v2) matrix-org/matrix-spec-proposals#1767
• MSC2676: Message editing matrix-org/matrix-spec-proposals#2676

[MadLittleMods]

As an update, the reply artifact was caused by having the "Show hidden events" lab turned on a bug where the tile still showed replies for hidden events. The bug was fixed by matrix-org/matrix-react-sdk#6796

In terms of actually getting the edited relation reply to show up, I think I just had the event format wrong. Instead of adding m.in_reply_to to the events' root m.relates_to field, I created a new m.relates_to inside of m.new_content. This way when the m.new_content replaces the content of the original event, it has the new relation 🌈. This does require an additional change to element-web though, matrix-org/matrix-react-sdk#6809 which hopefully passes the sniff test there in terms of something we want/can do with the Matrix API.

{
  "type": "m.room.message",
  "content": {
    "body": " * foo bar",
    "msgtype": "m.text",
    "m.new_content": {
      "body": "foo bar",
      "msgtype": "m.text",
      "m.relates_to": {
        "m.in_reply_to": {
          "event_id": "$qkjmFBTEc0VvfVyzq1CJuh1QZi_xDIgNEFjZ4Pq34og"
        }
      }
    },
    "m.relates_to": {
      "rel_type": "m.replace",
      "event_id": "$lX9MRe9ZTFOOvnU8PRVbvr1wqGtYvNQ1rSot-iUTN5k"
    }
  }
}