EEx v1.0.5 EEx.Engine behaviour

Basic EEx engine that ships with Elixir.

An engine needs to implement three functions:

  • handle_body(quoted) - receives the final built quoted expression, should do final post-processing and return a quoted expression.

  • handle_text(buffer, text) - it receives the buffer, the text and must return a new quoted expression.

  • handle_expr(buffer, marker, expr) - it receives the buffer, the marker, the expr and must return a new quoted expression.

    The marker is what follows exactly after <%. For example, <% foo %> has an empty marker, but <%= foo %> has "=" as marker. The allowed markers so far are: "" and "=".

    Read handle_expr/3 below for more information about the markers implemented by default by this engine.

EEx.Engine can be used directly if one desires to use the default implementations for the functions above.

Summary

Functions

Handles assigns in quoted expressions

The default implementation implementation simply returns the given expression

Implements expressions according to the markers

The default implementation simply concatenates text to the buffer

Functions

handle_assign(arg)

Handles assigns in quoted expressions.

This can be added to any custom engine by invoking handle_assign/3 with Macro.prewalk/1:

def handle_expr(buffer, token, expr) do
  expr = Macro.prewalk(expr, &EEx.Engine.handle_assign/1)
  EEx.Engine.handle_expr(buffer, token, expr)
end
handle_body(quoted)

The default implementation implementation simply returns the given expression.

handle_expr(buffer, binary2, expr)

Implements expressions according to the markers.

<% Elixir expression - inline with output %>
<%= Elixir expression - replace with result %>

All other markers are not implemented by this engine.

handle_text(buffer, text)

The default implementation simply concatenates text to the buffer.

Callbacks

handle_body(arg0)

Specs

handle_body(Macro.t) :: Macro.t
handle_expr(arg0, binary, arg2)

Specs

handle_expr(Macro.t, binary, Macro.t) :: Macro.t
handle_text(arg0, binary)

Specs

handle_text(Macro.t, binary) :: Macro.t