Re: [PATCH datacenter-manager] views: catch unknown widget types

["Lukas Wagner" <l.wagner@proxmox.com>]

On Mon Apr 27, 2026 at 1:13 PM CEST, Dominik Csapak wrote:
> If there is a mismatch between backend and frontend, (e.g. after an
> update or during development) deserialize unknown widget types in a way
> that we can still show the remaining widgets.
>
> Use serde's untagged + flatten feature so we can save all extra
> parameters and send it back to the backend.
>
> In the api, we reject all view updates that contain unknown widgets,
> since the frontend should never send any types the backend does not
> know.
>
> Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
> ---
>  lib/pdm-api-types/Cargo.toml   |  1 +
>  lib/pdm-api-types/src/views.rs | 30 +++++++++++++++++++++++++++++-
>  server/src/api/config/views.rs | 20 +++++++++++++++-----
>  ui/src/dashboard/view.rs       | 25 ++++++++++++++++++++++++-
>  4 files changed, 69 insertions(+), 7 deletions(-)
>
> diff --git a/lib/pdm-api-types/Cargo.toml b/lib/pdm-api-types/Cargo.toml
> index 7aa7b64e..0c84d301 100644
> --- a/lib/pdm-api-types/Cargo.toml
> +++ b/lib/pdm-api-types/Cargo.toml
> @@ -12,6 +12,7 @@ http.workspace = true
>  regex.workspace = true
>  serde.workspace = true
>  serde_plain.workspace = true
> +serde_json.workspace = true
>  
>  proxmox-acme-api.workspace = true
>  proxmox-access-control = { workspace = true, features = ["acl"] }
> diff --git a/lib/pdm-api-types/src/views.rs b/lib/pdm-api-types/src/views.rs
> index c1885828..89281bb3 100644
> --- a/lib/pdm-api-types/src/views.rs
> +++ b/lib/pdm-api-types/src/views.rs
> @@ -1,4 +1,7 @@
> -use std::{fmt::Debug, fmt::Display, str::FromStr, sync::OnceLock};
> +use std::collections::HashMap;
> +use std::fmt::{Debug, Display};
> +use std::str::FromStr;
> +use std::sync::OnceLock;
>  
>  use anyhow::{bail, Error};
>  use const_format::concatcp;
> @@ -255,6 +258,24 @@ pub enum ViewLayout {
>      },
>  }
>  
> +impl ViewLayout {
> +    /// Tests if this layout has unknown widget types
> +    pub fn has_unknown_widgets(&self) -> bool {
> +        match self {
> +            ViewLayout::Rows { rows } => {
> +                for row in rows {
> +                    for widget in row {
> +                        if let WidgetType::UnknownWidget { .. } = widget.r#type {
> +                            return true;
> +                        }
> +                    }
> +                }
> +            }
> +        }
> +        false
> +    }
> +}
> +
>  #[derive(Serialize, Deserialize, PartialEq, Clone)]
>  #[serde(rename_all = "kebab-case")]
>  pub struct RowWidget {
> @@ -312,6 +333,13 @@ pub enum WidgetType {
>          #[serde(skip_serializing_if = "Option::is_none")]
>          remote_type: Option<RemoteType>,
>      },
> +    #[serde(untagged)]
> +    #[serde(rename_all = "kebab-case")]
> +    UnknownWidget {
> +        widget_type: String,
> +        #[serde(flatten)]
> +        extra: HashMap<String, serde_json::Value>,
> +    },

This is `pub` and should therefore have some doc comments. Seems
valuable to me to express the 'catch-all' behavior there.

>  }
>  

Looks good to me otherwise.

Tested it by applying this patch and then modifying views.cfg manually,
changing the widget-type of one widget to something unknown.

Reviewed-by: Lukas Wagner <l.wagner@proxmox.com>
Tested-by: Lukas Wagner <l.wagner@proxmox.com>