pyctpp2 0.9.1

Python interface to CTPP2 library.

Contents

• Example of usage

• CTPP2 tags

  • TMPL_var

  • TMPL_if, TMPL_unless

  • TMPL_loop, TMPL_foreach

  • TMPL_include

  • TMPL_comment

  • TMPL_block, TMPL_call

• CTPP2 built-in functions

  • AVG

  • BASE64_ENCODE

  • BASE64_DECODE

  • CAST

  • CONCAT

  • DATE_FORMAT

  • DEFAULT

  • DEFINED

  • FORM_PARAM

  • GETTEXT, (_)

  • HMAC_MD5

  • HREF_PARAM

  • HTMLESCAPE

  • ICONV

  • IN_SET

  • JSESCAPE

  • JSON

  • LOG

  • MD5

  • MAX

  • MB_SIZE

  • MB_SUBSTR

  • MB_TRUNCATE

  • MIN

  • NUM_FORMAT

  • OBJ_DUMP

  • RANDOM

  • SIZE

  • SUBSTR

  • TRUNCATE

  • URIESCAPE

  • URLESCAPE

  • VERSION

  • XMLESCAPE

  • WMLESCAPE

• CHANGES

  • 0.9.1 (13.01.2011)

  • 0.9.0 (11.01.2011)

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)>

CHANGES

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.