Baking badges - PNG metadata handler. More...

Public Member Functions
	__construct (string $contents)
	Prepares file for handling metadata.

	add_chunks (string $type, string $key, string $value)
	Adds a chunk with keyword and data to the file content.

	check_chunks (string $type, string $check)
	Checks if a key already exists in the chunk of said type.

Detailed Description

Baking badges - PNG metadata handler.

Author: Yuliya Bozhko yuliy.nosp@m.a.bo.nosp@m.zhko@.nosp@m.tota.nosp@m.ralms.nosp@m..com

Constructor & Destructor Documentation

core_badges\png_metadata_handler::__construct ( string $contents )

Prepares file for handling metadata.

Verifies that this file is a valid PNG file. Unpacks file chunks and reads them into an array.

Parameters

string $contents File content as a string

core_badges\png_metadata_handler::add_chunks	(	string	$type,
		string	$key,
		string	$value )

Adds a chunk with keyword and data to the file content.

Chunk is added to the end of the file, before IEND image trailer.

Parameters

string	$type	Chunk type, like iTXt, tEXt, etc.
string	$key	Keyword that needs to be added.
string	$value	Currently an assertion URL that is added to an image metadata.

Return values

string#$result File content with a new chunk as a string. Can be used in file_put_contents() to write to a file.

Exceptions

moodle_exception when unsupported chunk type is defined.

core_badges\png_metadata_handler::check_chunks	(	string	$type,
		string	$check )

Checks if a key already exists in the chunk of said type.

We need to avoid writing same keyword into file chunks.

Parameters

string	$type	Chunk type, like iTXt, tEXt, etc.
string	$check	Keyword that needs to be checked.

Return values

boolean (true|false) True if file is safe to write this keyword, false otherwise.

The documentation for this class was generated from the following file: