The template parser reads views from the view subdirectory of a gluon-web application (/lib/gluon/config-mode/view for the config mode, lib/gluon/status-page/view for the status page). Writing own views should usually be avoided in favour of using Models with their predefined views.

Views are partial HTML pages, with additional template tags that allow to embed Lua code and translation strings. The following tags are defined:

  • <%%> evaluates the enclosed Lua expression.

  • <%|%> evaluates the enclosed Lua expression and prints its value.

  • <%=%> evaluates the enclosed Lua expression and prints its value without escaping HTML entities. This is useful when the value contains HTML code.

  • <%+%> includes another template.

  • <%:%> translates the enclosed string using the loaded i18n catalog.

  • <%_%> translates the enclosed string without escaping HTML entities in the translation. This only makes sense when the i18n catalog contains HTML code.

  • <%#%> is a comment.

All of these also come in the whitespace-stripping variants <%- and -%> that remove all whitespace before or after the tag.

Complex combinations of HTML and Lua code are possible, for example:

  <% if foo then %>
  <% end %>

Variables and functions

Many call sites define additional variables (for example, model templates can access the model as self and a unique element ID as id), but the following variables and functions should always be available for the embedded Lua code:

  • renderer: The template renderer

  • http: The HTTP object

  • request: Table containing the path components of the current page

  • url (path): returns the URL for the given path, which is passed as a table of path components.

  • attr (key, value): Returns a string of the form key="value" (with a leading space character before the key).

    value is converted to a string (tables are serialized as JSON) and HTML entities are escaped. Returns an empty string when value is nil or false.

  • include (template): Includes another template.

  • node (path, …): Returns the controller node for the given page (passed as one argument per path component).

    Use node(unpack(request)) to get the node for the current page.

  • pcdata (str): Escapes HTML entities in the passed string.

  • urlencode (str): Escapes the passed string for use in an URL.

  • translate, _translate, translatef and i18n: see Internationalization support