Template Enum support

[RylanYancey]

I'd like to use Askama as follows:

#[derive(Template)]
#[derive(Serialize, Deserialize)]
pub enum QuestionData {
	#[template(path = "./templates/question/editor/multiple-text.html")]
	MultipleChoiceText {
		numbering: Numbering,
		text: Vec<String>,
	},

	#[template(path = "./templates/question/editor/multiple-image.html")]
	MultipleChoiceImage {
		numbering: Numbering,
		images: Vec<i32>,
	},

	#[template(path = "./templates/question/editor/truefalse.html")]
	TrueOrFalse,

	#[template(path = "./templates/question/editor/fillblank.html")]
	FillInTheBlank {
		sections: Vec<String>,
		starts_with_blank: bool,
	},

	#[template(path = "./templates/question/editor/short-answer.html")]
	ShortAnswer {
		answers: Vec<String>,
	},

	#[template(path = "./templates/question/editor/ranking-text.html")]
	RankingText {
		numbering: Numbering,
		items: Vec<String>,
	},

	#[template(path = "./templates/question/editor/ranking-image.html")]
	RankingImages {
		numbering: Numbering,
		items: Vec<i32>,
	},
}

#[derive(Serialize, Deserialize)]
pub enum Numbering {
	Letters,
	Numbers,
	Bullets,
}

Is this a possibility in the future?

[djc]

I'm not convinced. Why do you need this? Alternatively, could you do MultipleChoiceText(MultipleChoiceText) with struct MultipleChoiceText { numbering: Numbering, text: Vec<String> } instead? That should get you pretty close.

[klownie]

it would allow us to load different html files using a match statement without having to write something that clusters code.
for example i have a big match statement on my website for different posts, because i want each post to be unique without following a specific template.
this is how I coded it for now:

fn render_project_template(project: &str, high_res: bool) -> String {
    match project {
        "SamuConceptCharacter" => {
            debug!("loaded: SamuConceptCharacter");
            SamuConceptCharacter {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "Saint-John" => {
            debug!("loaded: Saint-John");
            SaintJohn {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "HomardRojas" => {
            debug!("loaded: HomardRojas");
            HomardRojas {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "CarbonixWorkerSuit" => {
            debug!("loaded: CarbonixWorkerSuit");
            CarbonixWorkerSuit {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "ClimbingExoSuit" => {
            debug!("loaded: ClimbingExoSuit");
            ClimbingExoSuit {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "ClimbingExoSuit3d" => {
            debug!("loaded: ClimbingExoSuit3d");
            ClimbingExoSuit3d {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "Intru" => {
            debug!("loaded: Intru");
            Intru {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "TeamBlue" => {
            debug!("loaded: TeamBlue");
            TeamBlue {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "TribalYellowDemon" => {
            debug!("loaded: TribalYellowDemon");
            TribalYellowDemon {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        "UrbanWhiteCrowMan" => {
            debug!("loaded: UrbanWhiteCrowMan");
            UrbanWhiteCrowMan {
                project_name: project.into(),
                high_res,
            }
            .render()
            .unwrap()
        }
        _ => {
            error!("loaded: MissingProject");
            MissingProject {}.render().unwrap()
        }
    }
}

Introducing enums instead would make it easier to organise espaclialy when declaring the templates

[djc]

So this runs into a bunch of issues where the enum media type must match each of the variant template's media type, which I think is tricky to enforce correctly. I think you could do this with newtype variants for a bunch of template types and then having a simple manual Display or Template implementation for the enum itself.

[Kijewski]

There is prior discussion to this feature request in issue #666. askama-enum should still work fine for askama 0.12, if someone wants to fork the project.