View Source Phoenix.LiveView.TagEngine behaviour (Phoenix LiveView v0.20.12)

An EEx engine that understands tags.

This cannot be directly used by Phoenix applications. Instead, it is the building block by engines such as Phoenix.LiveView.HTMLEngine.

It is typically invoked like this:

EEx.compile_string(source,
  engine: Phoenix.LiveView.TagEngine,
  line: 1,
  file: path,
  caller: __CALLER__,
  source: source,
  tag_handler: FooBarEngine
)

Where :tag_handler implements the behaviour defined by this module.

Summary

Callbacks

annotate_body(caller)

Callback invoked to add annotations around the whole body of a template.

annotate_caller(file, line)

Callback invoked to add caller annotations before a function component is invoked.

classify_type(name)

Classify the tag type from the given binary.

handle_attributes(ast, meta)

Implements processing of attributes.

void?(name)

Returns if the given binary is either void or not.

Functions

component(func, assigns, caller)

Renders a component defined by the given function.

inner_block(name, list)

Define a inner block, generally used by slots.

Callbacks

annotate_body(caller)

@callback annotate_body(caller :: Macro.Env.t()) :: {String.t(), String.t()} | nil

Callback invoked to add annotations around the whole body of a template.

annotate_caller(file, line)

@callback annotate_caller(file :: String.t(), line :: integer()) :: String.t() | nil

Callback invoked to add caller annotations before a function component is invoked.

classify_type(name)

@callback classify_type(name :: binary()) :: {type :: atom(), name :: binary()}

Classify the tag type from the given binary.

This must return a tuple containing the type of the tag and the name of tag. For instance, for LiveView which uses HTML as default tag handler this would return {:tag, 'div'} in case the given binary is identified as HTML tag.

You can also return {:error, "reason"} so that the compiler will display this error.

handle_attributes(ast, meta)

@callback handle_attributes(ast :: Macro.t(), meta :: keyword()) ::
  {:attributes, [{binary(), Macro.t()} | Macro.t()]} | {:quoted, Macro.t()}

Implements processing of attributes.

It returns a quoted expression or attributes. If attributes are returned, the second element is a list where each element in the list represents one attribute.If the list element is a two-element tuple, it is assumed the key is the name to be statically written in the template. The second element is the value which is also statically written to the template whenever possible (such as binaries or binaries inside a list).

void?(name)

@callback void?(name :: binary()) :: boolean()

Returns if the given binary is either void or not.

That's mainly useful for HTML tags and used internally by the compiler. You can just implement as def void?(_), do: false if you want to ignore this.

Functions

component(func, assigns, caller)

Renders a component defined by the given function.

This function is rarely invoked directly by users. Instead, it is used by ~H and other engine implementations to render Phoenix.Components. For example, the following:

<MyApp.Weather.city name="Kraków" />

Is the same as:

<%= component(
      &MyApp.Weather.city/1,
      [name: "Kraków"],
      {__ENV__.module, __ENV__.function, __ENV__.file, __ENV__.line}
    ) %>

inner_block(name, list)

(macro)

Define a inner block, generally used by slots.

This macro is mostly used by custom HTML engines that provide a slot implementation and rarely called directly. The name must be the assign name the slot/block will be stored under.

If you're using HEEx templates, you should use its higher level <:slot> notation instead. See Phoenix.Component for more information.