Writing your own templates

• Any templates that in the templates folder at compilation time will be embedded in the compiled binary.
• If you only have the binary you can put templates in the folder user-templates. If a file from the user-templates folder has the same path as an embedded template, only the template from user-template will be rendered.
  • set the command line argument --user-templates or -u to set a custom folder
• the last file extension will be removed e.g: file.rs.go will be rendered to file.rs.
• For examples refer to the allready included templates

What fields are available inside templates?

Any of these fields will be accessible:

    pub struct TemplateContext<'a> {
        pub title: &'a String,
        pub description: &'a Option<String>,
        pub server: &'a Server,
        pub subscribe_channels: Vec<(&'a String, SimplifiedOperation)>,
        pub publish_channels: Vec<(&'a String, SimplifiedOperation)>,
        pub model: Model,
    }
    
    pub struct Model {
        pub message_models: Vec<RustSchemaRepresentation>,
        // pub enums: Vec<MultiStructEnum>,
    }
    
    pub struct SimplifiedOperation {
        pub unique_id: String,
        pub original_operation: Operation,
        // array, da es eine oder mehrere messages geben kann
        pub messages: Vec<SimplifiedMessage>,
        // pub multiple_messages_enum: Option<MultiStructEnum>,
    }
    
    pub struct MultiStructEnum {
        pub unique_id: String,
        pub messages: Vec<SimplifiedMessage>,
        pub struct_definition: String,
    }
    
    pub struct SimplifiedMessage {
        pub unique_id: String,
        pub original_message: Message,
        pub payload: Option<RustSchemaRepresentation>,
    }

• for more information about the fields available from these structs please refer to: all rust structs

Render to separate files

It is possible to generate files for each specific object in your AsyncAPI documentation. For example, you can specify a filename like $$handler$$.rs.go to generate a file for each publish_channel defined in your AsyncAPI spec.

This works with file templates that include the following in their name:

• $$handler$$
• $$producer$$
• $$model$$
• $$schemas$$

Functions available inside the templates

• to_lower(input: String) -> String converts String to lowercase
• key_exists(input: String) -> String checks if key exists
• camel_to_snake_case(input :String) -> String converts a String in camelCase to snake_case
• replace(input: String, from: String, to: String) -> String replaces from with to for input
  • Side Note: these functions are defined in src/generator/template_functions.rs feel free to extend then, if you have access to the source code.