pyctpp2 0.9.10

Python interface to CTPP2 library.

.. contents::
:depth: 2

Example of usage
================

First you should make template, file *hello.tmpl*::

Foo: <TMPL_var foo>
<TMPL_if array>
Here is loop body:
<TMPL_loop array>
Key: <TMPL_var key>
</TMPL_loop>
</TMPL_if>

Now create Python script::

#!/usr/bin/env python

import pyctpp2

if __name__ == '__main__':
engine = pyctpp2.Engine()

template = engine.parse('hello.tmpl')

result = template.render(foo='bar',
array=[{'key': 'first'}, {'key': 'second'}])

Now check output::

Foo: bar
Here is loop body:
Key: first
Key: second

CTPP2 tags
==========

CTPP2_ template language dialect contains next operators:

- <TMPL_var>
- <TMPL_if>
- <TMPL_elsif>
- <TMPL_else>
- <TMPL_unless>
- <TMPL_loop>
- <TMPL_foreach>
- <TMPL_udf>
- <TMPL_include>
- <TMPL_comment>
- <TMPL_block>
- <TMPL_call>

In order to simplify the make-up, all operators names are case insensitive,
that is why the notifications such as: **<TMPL_var** , **<TmPl_VaR** ,
**<tmpl_VAR** are equal.

But the names of variables are case sensitive, that's why for example:
**<TMPL_var ABC>**, **<TMPL_var abc>**, **<TMPL_var Abc>** are not in equal
state.

Parameters, which names starting with a symbol of underlining (for example
**__FIRST__**) are reserved names and should NOT be used by the
developer. Variable names can be composed of letters, numbers, and
underscores (_). Every variable name in CTPP2_ must start with a letter.

You can access subproperties (hash references to oher object) of variable
by specifying it after variable name separated by dot '.': **<TMPL_var
foo.bar>**.

TMPL_var
--------

**<TMPL_var VAR_NAME>**, **<TMPL_udf VAR_NAME>** - Direct parameter output.

In CTPP2_ template engine two types of variables are defined: local and
global. The sense of these two concepts is completely equal with a similar
idea in the other algorithmic languages such as *C++*.

For variable output use operator **<TMPL_var VAR_NAME>**.

*Example 1*:

:Template: ``"Hello, <b><TMPL_var username></b>!"``
:Parameter: ``{ 'username': 'Olga' }``
:Output: ``"Hello, Olga!"``

You can use user defined functions to make a variable output.

*Example 2*:

:Template: ``"<a href="/index.cgi?username=<TMPL_var URLESCAPE(username)>">"``
:Parameter: ``{ 'username': 'Андрей' }``
:Output: ``"<a href="/index.cgi?username=%C0%ED%E4%F0%E5%E9">"``

*Example 3*:

:Template: ``User <TMPL_var user.name> has id <TMPL_var user.id>``
:Parameter: ``{ 'user': { 'name': "Fred", 'id': 1234 }}``
:Output: ``User Fred has id 1234``

TMPL_if, TMPL_unless
--------------------

These operators impose condition on your template output, it depends on the
result of logical expression placed to the right of the operator's body.

CTPP2_ defines four operators of condition: **<TMPL_if LOGICAL_EXPR>**,
**<TMPL_elsif LOGICAL_EXPR>**, **<TMPL_else>** and
**<TMPL_unless LOGICAL_EXPR>**.

Operators evaluates logical expression to the result and according to it
executes or not the further instructions. You can also use variables (local
and global) and user defined functions inside of the operator's body.

*Example 1*::

<TMPL_if LOGICAL_EXPR>
Some instructions if result has true value.
<TMPL_elsif OTHER_EXPRESSION>
Some instructions if result has false value.
<TMPL_else>
Else-branch/
</TMPL_if>

<TMPL_unless LOGICAL_EXPR1>
Some instructions if result has false value.
<TMPL_elsif LOGICAL_EXPR2>
Some instructions if evaluation result of
LOGICAL_EXPR2 has true value.
<TMPL_else>
Some instructions if result has true value.
</TMPL_unless>

The branches of **<TMPL_elsif>** and **<TMPL_else>** are not firmly binds,
it means that the following notification is allowed:
**<TMPL_if LOGICAL_EXPR>** Some instructions **</TMPL_if>**.

Thus the operator **<TMPL_unless** differs from the operator **<TMPL_if**
in the executing some instructions if the evaluated value is false.

TMPL_loop, TMPL_foreach
-----------------------

The loop - The multiple repeating of some pre-defined actions.

The only type of loops has been defined in CTPP2_ - the forward running
over through the data array. The operator corresponding with this action
looks like the following::

<TMPL_loop MODIFIERS LOOP_NAME>
The LOOP instructions.
</TMPL_loop>

**TMPL_foreach** is loop with iterator::

<TMPL_foreach LOOP_NAME as ITER_NAME>
<TMPL_var ITER_NAME.VAR_NAME> <TMPL_var VAR_NAME>.
</TMPL_foreach>

If the name of iterator isn't specified, the variable is searched at first
inside of iterator, and then it is searched in global area of the data.

If you evidently put the mark to use context variables in the loop body,
CTPP2_ inserts seven special variables, called context vars. The names of
these variables start with the double underline, this fact points to their
system meaning.


Set of values for *context vars*:

**__FIRST__**
It sets to "1" during the first loop iteration, in other
cases not defined.

**__LAST__**
It sets to the last iteration number, otherwise is not defined.

**__INNER__**
It accommodates the number from the second to the pre-last
iteration, otherwise undefined.

**__ODD__**
The number of an odd iteration. For the even one - undefined.

**__COUNTER__**
The number of current iteration.

**__EVEN__**
Opposite to the **__ODD__** variable.

**__SIZE__**
The whole number of the loop iterations.

**__CONTENT__**
It contains value of current iteration.

TMPL_include
------------

In some cases it happens to allocate conveniently identical parts in
several templates (for example, heading or the menu on page) and to place
them in one file.

This is done by operator **<TMPL_include filename.tmpl>**.

*Example 1*:

File *main.tmpl*::

<TMPL_loop foo>
<TMPL_include "filename.tmpl"
map(bar : baz, orig_param : include_param)>
</TMPL_loop>

File *filename.tmpl*::

<TMPL_var baz>

You can rename variable in included templates. In example 1 variable *baz*
in file *filename.tmpl* was renamed to *bar* and *orig_param* to
*include_param*. This is useful when you include one template many times
in main template.

**Attention! You CAN NOT place a part of a loop or condition in separate
templates.**

In other words, this construction will not work:

*Example 2*:

File *main.tmpl*::

<TMPL_if foo>
<TMPL_include 'abc.tmpl'>

File *abc.tmpl*::

</TMPL_if>

TMPL_comment
------------

All characters between **<TMPL_comment>** and **</TMPL_comment>** are
ignored. This is useful to comment some parts of template.

TMPL_block, TMPL_call
---------------------

You can declare a block of code and call it by name:

*Example 1*::

<TMPL_block "foo"> <!-- Declare block with name "foo" -->
... some foo's HTML and CTPP operators here ...
</TMPL_block>
<TMPL_block "bar"> <!-- Declare block with name "bar" -->
... some other HTML and/or CTPP operators here ...
</TMPL_block>

<TMPL_call block> <!-- Call block by name -->

CTPP2 built-in functions
========================

There are a variety of situations when you need to represent data according
to some condition. To simplify the solution of this problem CTPP2_ support
built-in functions. You can call them from the bodies of **<TMPL_if**,
**<TMPL_unless**, **<TMPL_var** and **<TMPL_udf** operators.

*Example 1*::

<TMPL_var HTMLESCAPE(name)>

<TMPL_if IN_SET(name, 1, 2, 3)>
Variable "name" is set to "1", "2" or "3".
</TMPL_if>

CTPP2_ support following built-in functions:

- AVG
- BASE64_ENCODE
- BASE64_DECODE
- CAST
- DATE_FORMAT
- DEFAULT
- DEFINED
- FORM_PARAM
- GETTEXT, (_)
- HMAC_MD5
- HREF_PARAM
- HTMLESCAPE
- ICONV
- IN_SET
- JSESCAPE
- JSON
- MD5
- MAX
- MB_SIZE
- MB_SUBSTR
- MB_TRUNCATE
- MIN
- NUM_FORMAT
- OBJ_DUMP
- RANDOM
- SIZE
- SUBSTR
- TRUNCATE
- URIESCAPE
- URLESCAPE
- VERSION
- XMLESCAPE
- WMLESCAPE

AVG
---

Function calculates average value of arguments.

*Arguments*:

:1: Type of used algorithm for calculation of average value. Admissible
values: 'a' (arithmetic), 'g' (geometric), 'h' (harmonic), 'q'
(quadratic).

:2..*: Values.

*Examples*::

<TMPL_var AVG('a', 1, 2, 3)>: 2
<TMPL_var AVG('g', 1, 2, 3)>: 1.81712059283
<TMPL_var AVG('h', 1, 2, 3)>: 1.63636363636
<TMPL_var AVG('q', 1, 2, 3)>: 2.16024689947

BASE64_ENCODE
-------------

Function codes the value in format Base64 (RFC 3548).

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var BASE64_ENCODE("Hello, World!")>

BASE64_DECODE
-------------

Function decodes the value from format Base64 (RFC 3548).

*Arguments*:

:1: Base64 string.

*Examples*::

<TMPL_var BASE64_DECODE("SGVsbG8sIFdvcmxkIQ==")>

CAST
----

Function can be used for conversion between types.

*Arguments*:

:1: Name of target type. Admissible values: "i[nteger]", "o[ctal]",
"d[ecimal]", "h[exadecimal]", "f[loat]", "s[tring]".

:2: Value.

*Examples*::

<TMPL_var CAST("int", 1.345)>: 1
<TMPL_var CAST('int', "010")>: 8
<TMPL_var CAST('dec', "010")>: 10
<TMPL_var CAST('oct', "010")>: 8
<TMPL_var CAST('hex', "010")>: 16
<TMPL_var CAST("float", var1)>

CONCAT
------

Function concatenates arguments.

*Arguments*:

:1..*: Values.

*Examples*::

<TMPL_var CONCAT('a', 1, 2, 3)>: a123

DATE_FORMAT
-----------

Function formats the date according to a template. Syntax of a template
completely matches with syntax for C-function *strftime*.

*Arguments*:

:1: Number of seconds since the Epoch.

:2: *strftime* template.

*Examples*::

<TMPL_var DATE_FORMAT(1200490323, "%Y-%m-%d %H:%M:%S")>
<TMPL_udf DATE_FORMAT(1200490323, "%Y-%m-%d %H:%M:%S")>

DEFAULT
-------

Function returns value of the second arguemtn in case the first isn't set.

*Arguments*:

:1: Value.

:2: Default value.

*Examples*::

<TMPL_var DEFAULT(foo, "bar")>

DEFINED
-------

Function returns true if the variable has the type which is distinct from
UNDEF.

*Arguments*:

:1: Value.

*Examples*::

<TMPL_if DEFINED(foo)>Foo defined!</TMPL_if>

FORM_PARAM
----------

The algorithm of function is similar HREF_PARAM. It is intended for a
output in forms of fields of type *hidden*. Replaces with itself::

<TMPL_if a>
<input type="hidden" name="param_a" value=<TMPL_var URLESCAPE(a)">
</TMPL_if>

*Arguments*:

:1: Name of parameter.

:2: Value wrapped up in URLESCAPE.

*Examples*::

<TMPL_udf FORM_PARAM("param_a", a)>

GETTEXT, (_)
------------

Function realizes system NLS support (Native Language Support, l18n).

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var GETTEXT(variable)>
<TMPL_var _(variable)>

HMAC_MD5
--------

Function generates HMAC_MD5 hash from arguments.

*Arguments*:

:1..*: Values.

*Examples*::

<TMPL_var HMAC_MD5("Data", "key")>

HREF_PARAM
----------

The algorithm of function is similar FORM_PARAM. It is intended for a
output in links. Replaces with itself::

<TMPL_if a>param_a=<TMPL_var URLESCAPE(a)></TMPL_if>

*Arguments*:

:1: Name of parameter.

:2: Value.

*Examples*::

<a href=/abc?<TMPL_udf HREF_PARAM("param_a", a)>

HTMLESCAPE
----------

Function replaces symbols ``<``, ``>``, ``"``, ``'``, ``&`` on ``&lt;``,
``&gt;``, ``&quot;``, ``#039;``, ``&amp;`` accordingly.

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var HTMLESCAPE(name)>
<TMPL_udf HTMLESCAPE(name)>

ICONV
-----

Function converts text from one encoding to another encoding.

*Arguments*:

:1: Encoding of the input.

:2: Encoding of the output.

:3: String value.

:4: Flags. Admissible values: 'i', 't'. Flag 'i' permits to convert string
with errors. Flag 't' enables transliteration.

*Examples*::

<TMPL_var ICONV("Windows-1251", "utf-8", "Здравствуй, мир!")>
<TMPL_var ICONV("utf-8", "utf-8", "Здравствуй, мир!", "ti")>

IN_SET
------

Function compares the first argument to other arguments.
Returns true if it is found though one coincidence.

*Arguments*:

:1..*: Values.

*Examples*::

<TMPL_if IN_SET(variable, "1", "2", "3")>
<TMPL_if IN_SET(variable, variable1, "2", variable2)>

JSESCAPE
--------

Function escapes symbols according to agreements of language ECMAScript
(Java Script).

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var JSESCAPE(foo)>

JSON
----

Function serializes object in format JSON.

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var JSON(foo)>

LOG
---

Function calculates value of a logarithm of number. If the base not
specified, returns the natural logarithm (base e).

*Arguments*:

:1: Number.

:2: Base.

*Examples*::

<TMPL_var LOG(2.7182818284)>
<TMPL_udf LOG(100, 10)>

MD5
---

Function generates MD5 hash from arguments.

*Arguments*:

:1..*: Values.

*Examples*::

<TMPL_var MD5("Hello, World!")>
<TMPL_var MD5("Hello", ", ", "World!")>

MAX
---

Function calculates the maximum value of arguments.

*Arguments*:

:1: Value.

:2..*: Values.

*Examples*::

<TMPL_var MAX(1, -2, 3)>: 3

MB_SIZE
-------

Function returns the size of object. It returns length for arrays and dicts,
count of characters for strings.

*Arguments*:

:1: String, array or dict value.

*Examples*::

<TMPL_var MB_SIZE(foo)>

MB_SUBSTR
---------

Function is intended for gaining multibyte (UTF-8) substring or
replacement of a part of a line.

*Arguments*:

:1: Input string.

:2: Start positiion.

:3: Count of characters.

:4: String of replacement.

*Examples*::

<TMPL_var SUBSTR('foobar', 2)>: oobar
<TMPL_var SUBSTR('foobar', 2, 3)>: oba
<TMPL_var SUBSTR('foobar', 2, 3, '1234')>: fo1234r

MB_TRUNCATE
-----------

Function truncates and output multibyte (UTF-8) lines.

*Arguments*:

:1: Input string.

:2: Count of characters.

:3: Tail string.

*Examples*::

<TMPL_var TRUNCATE('foobar', 3)>: foo
<TMPL_var TRUNCATE('foobar', 3, '...')>: foo...
<TMPL_var TRUNCATE('foobar', 100, '...')>: foobar

MIN
---

Function calculates the minimum value of arguments.

*Arguments*:

:1: Value.

:2..*: Values.

*Examples*::

<TMPL_var MIN(1, -2, 3)>: -2

NUM_FORMAT
----------

Function formats integer and adds period sign.

*Arguments*:

:1: Integer value.

:2: Period sign.

*Examples*::

<TMPL_var NUM_FORMAT(variable, ",")>
<TMPL_udf NUM_FORMAT(variable, ".")>

OBJ_DUMP
--------

Function outputs dump of variables. If functions is called without
arguments, then it returns dump of all variables.

*Arguments*:

:1..*: Variables.

*Examples*::

<TMPL_var OBJ_DUMP()>
<TMPL_var OBJ_DUMP(var1, var2, var3)>

RANDOM
------

Function generates pseudorandom number. It returns value from range [0,
RAND_MAX] without arguments. It returns value from range [0, argument] with
1 argument.

*Arguments*:

:1: First value.

:2: Second value.

*Examples*::

<TMPL_var RANDOM()>
<TMPL_udf RANDOM(10)>
<TMPL_udf RANDOM(1.5, 2.5)>

SIZE
----

Function returns the size of object. It returns length for arrays and dicts,
count of bytes for strings.

*Arguments*:

:1: String, array or dict value.

*Examples*::

<TMPL_var MB_SIZE(foo)>

SUBSTR
------

Function is intended for gaining substring or
replacement of a part of a line.

*Arguments*:

:1: Input string.

:2: Start positiion.

:3: Count of characters.

:4: String of replacement.

*Examples*::

<TMPL_var SUBSTR('foobar', 2)>: oobar
<TMPL_var SUBSTR('foobar', 2, 3)>: oba
<TMPL_var SUBSTR('foobar', 2, 3, '1234')>: fo1234r

TRUNCATE
--------

Function truncates and output lines.

*Arguments*:

:1: Input string.

:2: Count of characters.

:3: Tail string.

*Examples*::

<TMPL_var TRUNCATE('foobar', 3)>: foo
<TMPL_var TRUNCATE('foobar', 3, '...')>: foo...
<TMPL_var TRUNCATE('foobar', 100, '...')>: foobar

URIESCAPE
---------

Function is completely similar to function URLESCAPE except that the blank
symbol is coded not as "+", and as %20.

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var URIESCAPE(name)>
<TMPL_udf URIESCAPE(name)>

URLESCAPE
---------

Function replaces symbols %XX, where XX - a hexadecimal code of a symbol.

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var URLESCAPE(name)>
<TMPL_udf URLESCAPE(name)>

VERSION
-------

Function returns current versions of standard library CTPP2_ and the virtual
machine. Function returns the expanded output with the argument "full".

*Arguments*:

:1: Admissible value: "full".

*Examples*::

<TMPL_var VERSION()>
<TMPL_var VERSION("full")>

XMLESCAPE
---------

Function replaces symbols ``<``, ``>``, ``"``, ``'``, ``&`` on ``&lt;``,
``&gt;``, ``&quot;``, ``&apos;``, ``&amp;`` accordingly.

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var XMLESCAPE(name)>
<TMPL_udf XMLESCAPE(name)>

WMLESCAPE
---------

Function replaces symbols ``<``, ``>``, ``"``, ``'``, ``$``, ``&`` on ``&lt;``,
``&gt;``, ``&quot;``, ``&apos;``, ``$$``, ``&amp;`` accordingly.

*Arguments*:

:1: Value.

*Examples*::

<TMPL_var WMLESCAPE(name)>
<TMPL_udf WMLESCAPE(name)>

.. _CTPP2: http://ctpp.havoc.ru/


CHANGES
=======

0.9.10 (17.05.2011)
------------------

- Added duplicate information about dicts for HASH_ELEMENT support.

0.9.9 (17.05.2011)
------------------

- Fixed HASH_ELEMENT support.

0.9.8 (12.05.2011)
------------------

- Fixed extract method 'ctpp2' for Babel.

0.9.7 (28.04.2011)
------------------

- Fixed support of render params with types.LongType.

0.9.6 (19.04.2011)
------------------

- Fixed extract method 'ctpp2' for Babel.

0.9.5 (19.04.2011)
------------------

- Fixed build with Cython.

0.9.4 (19.04.2011)
------------------

- Added extract method 'ctpp2' for Babel.

0.9.3 (15.04.2011)
------------------

- Added support of i18n.
- Fixed tests.
- Changed Template and Engine API.

0.9.2 (28.03.2011)
------------------

- Fixed installation by pip.

0.9.1 (13.01.2011)
------------------

- Added COPYING.txt.
- Added support of traversable objects.
- Some bug fixes.

0.9.0 (11.01.2011)
------------------

- Initial release.