Data Parser

The Data Parser class is responsible for parsing the server response into a common format. This format is determined by the module and typically includes returning objects that conform to a particular interface.

There are several standard parsers included to handle common data types:

• INIFileParser - Parses .ini files into sections and key/value pairs
• JSONDataParser - Parses JSON data. Typically you would extend this to convert the data into objects.
• PassthroughDataParser - Does not parse the data. Useful in situations where the data needs to be returned as is.
• RSSDataParser - Parses RSS data into individual RSS items
• XMLDataParser - Parses XML data. This class needs to be extended to handle the elements appropriately.

Methods to Implement

• parseData($data) - This method is called to actually parse the data from the request. Note that for some retrievers (i.e. DatabaseRetrievers or LDAPRetrievers) the value will actually be a resource rather than a string. It should return the data parsed into it’s appropriate value. The correct value type depends on the underlying data model. Typically this would be an object or an array of objects.

Internal Methods

• setTotalItems($total) - This should be called if the service provides a field to indicate the total number of items in the request (and the number of items actually returned has been limited). This assists with paging.
• getContext($val) - Retrieves a context value that was set by the retriever to assist with parsing the data. Examples include resource variables and state information.

Special Properties

To customize the behavior of the parser, you can override certain properties:

• parseMode - should be one of the class constants:
  • DataParser::PARSE_MODE_RESPONSE (default) - this parser will parse a DataResponse object. The DataParser class implements the parseResponse method that will call the parseData method to parse the contents of the response
  • DataParser::PARSE_MODE_FILE - this parser expects to receive a file name that points to a file to parse. This is useful for parsers that utilize functions that act on files rather than strings.

Initialization Values

Retrievers typically are sent the values of a configuration file. There are several values that used by all retrievers to configure the behavior of a particular instance:

• HALT_ON_PARSE_ERRORS - If false then the parser should catch any exceptions while parsing and continue.

Certain subclasses have additional configuration values.

Writing A Parser

<?php

class MyDataParser extends DataParser
{

    protected function parseData($data) {

        // Take the data and parse it into objects or an array of objects

        return $parsedData;
    }
}