using drupal源代码

INFORMATION FOR DEVELOPERS Once the Date API is installed, all functions in the API are available to be used anywhere by any module. If the Date Timezone module is installed, the system site timezone selector and the user timezone selectors are overwritten to allow the selection of timezone names instead of offsets. Proper timezone conversion requires knowledge of those timezone names, something that is not currently available in Drupal core, and the change in selectors makes it possible to track it. In most cases, you should enable the Date Timezone module any time you use the Date API to be able to set the site and user timezone names. It is not enabled by default in case another module is setting timezone names in the database. The API uses the PHP 5.2 date functions to create and manipulate dates, and contains an option module that will emulate those functions in earlier versions of PHP. If you are using PHP 4 or PHP 5.0 or 5.1, native date handling won't work right. Install the Date_PHP4 module to enable wrapper functions so this code will work in old PHP versions. Example, the following will create a date for the local value in one timezone, adjust it to a different timezone, then return the offset in seconds in the new timezone for the input date; The offset will be adjusted for both the timezone difference and daylight savings time, if necessary: $date = date_create('2007-03-11 02:00:00', timezone_open('America/Chicago')); $chicago_time = date_format('Y-m-d H:i', $date); print 'At '. $chicago_time .' in Chicago, the timezone offset in seconds was '. date_offset_get($date); date_timezone_set($date, timezone_open('Europe/Berlin'); $berlin_time = date_format($date, 'Y-m-d H:i'); print 'It was '. $berlin_time .' in Berlin when it was '. $chicago_time .' in Chicago.'; print 'At that time in Berlin, the timezone offset in seconds was '. date_offset_get($date); A helper function is available, date_make_date($string, $timezone, $type), where $string is a unixtimestamp, an ISO date, or a string like YYYY-MM-DD HH:MM:SS, $timezone is the name of the timezone this date is in, and $type is the type of date it is (DATE_UNIX, DATE_ISO, or DATE_DATETIME). It create and return a date object set to the right date and timezone. Simpletest tests for these functions are included in the package. Available functions include the following (more documentation is provided in the files): ============================================================================ Date PHP4 Module ============================================================================ PHP 4 substitutions for the PHP 5 date functions are supplied. Use the PHP 5 functions in your code as they would normally be used and the PHP 4 alternatives will be automatically be substituted in when needed. You cannot do everything with these functions that can be done in PHP 5, but you can create dates, find timezone offsets, and format the results. Timezone handling uses native PHP 5 functions when available and degrades automatically for PHP 4 to use substitutions like those provided in previous versions of the Date and Event modules. Read the doxygen documentation in this module for more information about using the functions in ways that will work in PHP 4. Simpletest tests for the PHP 4 equivalent functions are included in the package. The following functions are emulated in PHP4: date_create() date_date_set() date_format() date_offset_get() date_timezone_set() timezone_abbreviations_list() timezone_identifiers_list() timezone_offset_get() timezone_open() ============================================================================ Preconfigured arrays ============================================================================ Both translated and untranslated values are available. The date_week_days_ordered() function will shift an array of week day names so it starts with the site's first day of the week, otherwise the weekday names start with Sunday as the first value, the expected order for many php and sql functions. date_month_names(); date_month_names_abbr(); date_month_names_untranslated(); date_week_days(); date_week_days_abbr(); date_week_days_untranslated(); date_week_days_ordered(); date_years(); date_hours(); date_minutes(); date_seconds(); date_timezone_names(); date_ampm(); ============================================================================ Miscellaneous date manipulation functions ============================================================================ Pre-defined constants and functions that will handle pre-1970 and post-2038 dates in both PHP 4 and PHP 5, in any OS. Dates can be converted from one type to another and date parts can be extracted from any date type. DATE_DATETIME DATE_ISO DATE_UNIX DATE_ARRAY DATE_OBJECT DATE_ICAL date_convert() date_is_valid(); date_part_is_valid(); date_part_extract(); ============================================================================ Date calculation and navigation ============================================================================ date_diff() will find the time difference between any two days, measured in seconds, minutes, hours, days, months, weeks, or years. date_days_in_month(); date_days_in_year(); date_weeks_in_year(); date_last_day_of_month(); date_day_of_week(); date_day_of_week_name(); date_diff(); ============================================================================ Date regex and format helpers ============================================================================ Pre-defined constants, an array of date format strings and their equivalent regex strings. DATE_REGEX_LOOSE is a very loose regex that will pull date parts out of an ISO date with or without separators, using either 'T' or a space to separate date and time, and with or without time. date_format_date() is similar to format_date(), except it takes a date object instead of a timestamp as the first parameter. DATE_FORMAT_ISO DATE_FORMAT_DATETIME DATE_FORMAT_UNIX DATE_FORMAT_ICAL DATE_REGEX_ISO DATE_REGEX_DATETIME DATE_REGEX_LOOSE date_format_date(); date_t() date_short_formats(); date_medium_formats(); date_long_formats(); date_format_patterns(); ============================================================================ Standardized ical parser and creator ============================================================================ The iCal parser is found in date_api_ical.inc, which is not included by default. Include that file if you want to use these functions: Complete rewrite of ical imports to parse vevents, vlocations, valarms, and all kinds of timezone options and repeat rules for ical imports. The function now sticks to parsing the ical into an array that can be used in various ways. It no longer trys to convert timezones while parsing, instead a date_ical_date_format() function is provided that can be used to convert from the ical timezone to whatever timezone is desired in the results. Repeat rules are parsed into an array which other modules can manipulate however they like to create additional events from the results. date_ical_export(); date_ical_import(); date_ical_date_format(); ============================================================================ Helpers for portable date SQL ============================================================================ The SQL functions are found in date_api_sql.inc, which is not included by default. Include that file if you want to use these functions: date_sql(); date_server_zone_adj(); date_sql_concat(); date_sql_pad(); ============================================================================ Date forms and validators ============================================================================ Reusable, configurable, self-validating FAPI date elements are found in date_api_elements.inc, which is not included by default. Include it if you want to use these elements. To use them, create a form element