Glossary

.ttl

File containing tayra template script. These templates can be compiled into an intermediate .py file which can then be loaded and executed, with context, to generate the final .html file.

attributes

Attributes are key,value pairs. They follow the same syntax defined by HTML attributes and are translated as it is.

comment

Two types of commenting are allowed, one that will be translated along with template script and the other that will be silently ignored. The former type is defined using HTML comment syntax and the later type starts with a double hash ## and spans a single line.

directives

Directives are meta constructs that provide more information on how to interpret rest of the template script. Specifying document-type, importing other ttl files, inheriting a base layout, plugin definition are possible through directives.

escape filtering

Before substituting an evaluated expressio they are string-ified and optionally piped through filter handlers. Typically these filters will perform actions like html encoding, url encoding etc ...

expressions

A key requirement in templated HTML page is to be able to substitute variable content based on the context. In tayra, like many other templating language, substitution is performed using ${ ... } syntax. Text between ${ and } will be interpreted as python expression, and the value emitted by the expression will be string-ified and filtered before substituted in HTML output.

filter-blocks

Blocks of text that starts and ends with its own syntax, does not follow indentation rules and have their own parsing logic. New type of filter blocks can be defined and extended by plugins. Plugins implementing filter blocks directly take part in compilation passes.

global context

Global context is the context passed by the caller while translating .ttl documents into HTML text. Since tayra embeds python programming within the template document, it is possible to create side-effects to global context using globals() or using :py: filter-block.

indentation

HTML is all about nested tags and text content. A HTML document is naturally organised as a tree with a root-node. Hence tayra took its inspiration from HAML (of RoR) and imposes a strict indentation between parent tag and its children. In general, each indentation level takes up to 2 blank-space. Thus, for a child tag that is nested 3 levels deep should start with 6 blank-spaces. The indentation syntax is followed very strictly unless otherwise explicitly mentioned.

interface

Plugin interface, follows pluggdapps component system. Interfaces are called at specific points by core language, some are called during compile time, others are called at run-time. Plugins can implement one or more interfaces to extend the language definition.

local context

Inside templates, functions and interface methods can create a local context of its own during execution. Even the root level template text that is not part of any function or interface-method will be processed under an implicitly defined function called body().

plugin

Plugins are pluggdapps components implementing one or more interfaces. They are the only means available to extend the language.

specifiers

Specifiers are tokens, strings and other structures that can be included inside a tag element within the angle-brackets. Some specifiers are common to all tag elements while others are specific to certain tags. Plugins defining the tags have freedom to define their own specifier syntax. Note that specifiers are delimited by whitespace.

statements

Statements are programmable logic, coded in python, that spans an entire line and typically starts with @ or @@. Control block statements like if-elif-else and for/while starts with @ character. Assignment statements start with @@ prefix.

style

Style attribute is an often used attribute in HTML, hence a special syntax is provided off-the-shelf, { ... }. Text between curly brace will be interpreted as the element’s style.

tag

Typically a tag in a template text has an exact correspondence to HTML tags. Plugins can also define custom tags that are concise and sophisticated. It starts with an angle bracket <, a tagname followed by a sequence of name,value pairs called tag attributes and finally ends with >.

Other than this it can also contain expressions, shortcut tokens, style specifiers within the angle-brackets. Since indentation is strictly enforced, there is no need to close the tag with </...> markup, like in HTML. Tags are handled by plugins to generate the corresponding HTML output.

tag-handlers

Tag handlers are plugins that handle template tag elements. If no tag-handlers are available for the tagname, a default handler will be used to translate the tag element in safest possible way.

template-module

Every template-script is compiled into a python module and more or less follow the semantics of a python module. The compiled template-scripts are interpreted as template-module.

template-plugin

A template-script implementing one or more interface specifications.

template-script

File or string containing text scripted using tayra template language syntax.