/ 
Text-Fragment-0.110
River stage one • 3 direct dependents • 3 total dependents
/ Text::Fragment

NAME

Text::Fragment - Manipulate fragments in text

VERSION

This document describes version 0.110 of Text::Fragment (from Perl distribution Text-Fragment), released on 2021-03-25.

SYNOPSIS

use Text::Fragment qw(list_fragments
                      get_fragment
                      set_fragment_attrs
                      insert_fragment
                      delete_fragment);

my $text = <<_;
foo = "some value"
baz = 0
_

To insert a fragment:

my $res = insert_fragment(text=>$text, id=>'bar', payload=>'bar = 2');

$res->[2]{text} will now contain:

foo = "some value"
baz = 0
bar = 2 # FRAGMENT id=bar

To replace a fragment:

$res = insert_fragment(text=>$res->[2], id='bar', payload=>'bar = 3');

$res->[2]{text} will now contain:

foo = "some value"
baz = 0
bar = 3 # FRAGMENT id=bar

and $res->[2]{orig_payload} will contain the payload before being replaced:

bar = 2

To delete a fragment:

$res = delete_fragment(text=>$res->[2], id=>'bar');

To list fragments:

$res = list_fragment(text=>$text);

To get a fragment:

$res = get_fragment(text=>$text, id=>'bar');

To set fragment attributes:

$res = set_fragment_attrs(text=>$text, id=>'bar', attrs=>{name=>'val', ...});

DESCRIPTION

A fragment is a single line or a group of lines (called payload) with a metadata encoded in the comment that is put adjacent to it (for a single line fragment) or enclosing it (for a multiline fragment). Fragments are usually used in configuration files or code. Here is the structure of a single-line fragment:

<payload> # <label> <attrs>

Here is the structure of a multi-line fragment:

# BEGIN <label> <attrs>
<payload>
# END <label> [<attrs>]

Label is by default FRAGMENT but can be other string. Attributes are a sequence of name=val separated by whitespace, where name must be alphanums only and val is zero or more non-whitespace characters. There must at least be an attribute with name id, it is used to identify fragment and allow the fragment to be easily replaced/modified/deleted from text. Attributes are optional in the ending comment.

Comment character used is by default # (shell-style comment), but other comment styles are supported (see below).

Examples of single-line fragments (the second example uses c-style comment and the third uses cpp-style comment):

RSYNC_ENABLE=1 # FRAGMENT id=enable
some text /* FRAGMENT id=id2 */
some text // FRAGMENT id=id3 foo=1 bar=2

An example of multi-line fragment (using html-style comment instead of shell):

<!-- BEGIN FRAGMENT id=id4 -->
some
lines
of
text
<!-- END FRAGMENT id=id4 -->

Another example (using ini-style comment):

; BEGIN FRAGMENT id=default-settings
register_globals=On
extension=mysql.so
extension=gd.so
memory_limit=256M
post_max_size=64M
upload_max_filesize=64M
browscap=/c/share/php/browscap.ini
allow_url_fopen=0
; END FRAGMENT

FUNCTIONS

delete_fragment

Usage:

delete_fragment(%args) -> [status, msg, payload, meta]

Delete fragment in text.

If there are multiple occurences of fragment (which is considered an abnormal condition), all occurences will be deleted.

Newline deletion behaviour: if fragment at the bottom of text does not end with newline (which is considered bad style), the text after the fragment is deleted will also not end with newline.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • comment_style => str (default: "shell")

    Comment style.

  • id* => str

    Fragment ID.

  • label => str|code (default: "FRAGMENT")

    Comment label.

  • text* => str

    The text to delete fragment from.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (payload) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: A hash of result (hash)

Will return status 200 if operation is successful and text is deleted. The result is a hash with the following keys: text will contain the new text, orig_payload will contain the original fragment payload before being deleted, orig_fragment will contain the original fragment. If there are multiple occurences (which is considered an abnormal condition), only the last deleted fragment will be returned in orig_payload and orig_fragment.

Will return status 304 if nothing is changed (i.e. when the fragment that needs to be deleted already does not exist in the text).

get_fragment

Usage:

get_fragment(%args) -> [status, msg, payload, meta]

Get fragment with a certain ID in text.

If there are multiple occurences of the fragment with the same ID ,

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • comment_style => str (default: "shell")

    Comment style.

  • id* => str

    Fragment ID.

  • label => str (default: "FRAGMENT")

    Comment label.

  • text* => str

    The text which contain fragments.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (payload) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: Fragment (array)

Will return status 200 if fragment is found. Result will be a hash with the following keys: raw (string), payload (string), attrs (hash), id (string, can also be found in attributes).

Return 404 if fragment is not found.

insert_fragment

Usage:

insert_fragment(%args) -> [status, msg, payload, meta]

Insert or replace a fragment in text.

Newline insertion behaviour: if fragment is inserted at the bottom and text does not end with newline (which is considered bad style), the inserted fragment will also not end with newline. Except when original text is an empty string, in which case an ending newline will still be added.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • attrs => hash (default: {})

  • comment_style => str (default: "shell")

    Comment style.

  • good_pattern => str

    Regex pattern which if found means fragment need not be inserted.

  • id* => str

    Fragment ID.

  • label => str (default: "FRAGMENT")

    Comment label.

  • payload* => str

    Fragment content.

  • replace_pattern => str

    Regex pattern which if found will be used for placement of fragment.

    If fragment needs to be inserted into file, then if replace_pattern is defined then it will be searched. If found, fragment will be placed to replace the pattern. Otherwise, fragment will be inserted at the end (or beginning, see top_style) of file.

  • text* => str

    The text to insert fragment into.

  • top_style => bool (default: 0)

    Whether to append fragment at beginning of file instead of at the end.

    Default is false, which means to append at the end of file.

    Note that this only has effect if replace_pattern is not defined or replace pattern is not found in file. Otherwise, fragment will be inserted to replace the pattern.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (payload) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: A hash of result (hash)

Will return status 200 if operation is successful and text is changed. The result is a hash with the following keys: text will contain the new text, orig_payload will contain the original payload before being removed/replaced, orig_fragment will contain the original fragment (or the text that matches replace_pattern).

Will return status 304 if nothing is changed (i.e. if fragment with the same payload that needs to be inserted already exists in the text).

list_fragments

Usage:

list_fragments(%args) -> [status, msg, payload, meta]

List fragments in text.

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • comment_style => str (default: "shell")

    Comment style.

  • label => str (default: "FRAGMENT")

    Comment label.

  • text* => str

    The text which contain fragments.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (payload) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: List of fragments (array)

Will return status 200 if operation is successful. Result will be an array of fragments, where each fragment is a hash containing these keys: raw (string), payload (string), attrs (hash), id (string, can also be found in attributes).

set_fragment_attrs

Usage:

set_fragment_attrs(%args) -> [status, msg, payload, meta]

Set/unset attributes of a fragment.

If there are multiple occurences of the fragment with the same ID ,

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • attrs* => hash

    To delete an attribute in the fragment, you can set the value to undef.

  • comment_style => str (default: "shell")

    Comment style.

  • id* => str

    Fragment ID.

  • label => str (default: "FRAGMENT")

    Comment label.

  • text* => str

    The text which contain fragments.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (payload) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: New text and other data (array)

Will return status 200 if fragment is found. Result will be a hash containing these keys: text (string, the modified text), orig_attrs (hash, the old attributes before being modified).

Return 404 if fragment is not found.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Text-Fragment.

SOURCE

Source repository is at https://github.com/perlancar/perl-Text-Fragment.

BUGS

Please report any bugs or feature requests on the bugtracker website https://github.com/perlancar/perl-Text-Fragment/issues

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2021, 2017, 2016, 2015, 2014, 2012 by perlancar@cpan.org.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.