DtObj Lua Reference Documentation
chilkat.DtObj
Current Version: 11.7.0
Markdown version of this page for AI tools (v 11.7.0) · all AI docs
Chilkat.DtObj
Store and edit the year, month, day, hour, minute, and second as
individual properties.
Use the UTC flag to indicate whether the stored fields represent UTC or
local time.
Use alternate month and year properties when working with
Save and restore the object using Chilkat's compact internal serialized
date/time representation.
Pass
Use this class as a simple container rather than a full date/time
calculation or timezone-conversion engine.
For an extended overview, see
DtObj Class Overview.
Represent a date/time as simple editable fields.
Chilkat.DtObj is a lightweight date/time value object used by
Chilkat methods that need to pass or return individual date and time fields.
It stores values such as year, month, day, hour, minute, and second, along
with a flag indicating whether the value represents UTC or local time. It
also provides a compact serialization format for saving and restoring the
date/time value.
Simple date fields
UTC or local time
Struct tm compatibility
struct tm-style date/time conventions.
Serialize and restore
Used by other classes
DtObj values to Chilkat methods that require explicit
date/time fields or return date/time information.
Small and focused
DtObj, set or read the individual date/time
fields, check whether the value is UTC or local time, and pass the object to
another Chilkat method. Use serialization only when the date/time value needs
to be saved and restored in Chilkat's compact internal format.
Object Creation
local chilkat = require("chilkat")
local dt_obj = chilkat.DtObj.new()Creates the object (chilkat.DtObj() does the same). Lua's garbage collector frees it when it is no longer referenced; dt_obj:dispose() frees it at once, and in Lua 5.4 and later local dt_obj <close> = chilkat.DtObj.new() frees it when the block ends. Calling a method of a disposed object raises an error.
Errors
A method that fails returns nil followed by the error text, as io.open does: local body, err = dt_obj:method(...), where err is the object's last_error_text. Wrap the call in assert() to raise an error with that text instead. Methods that answer a question return true or false, numbers are returned as they are (check last_method_success where the description says a value means failure), and property reads and writes never fail for Chilkat reasons.
Misuse raises a Lua error: a wrong argument type or a missing argument (bad argument #1 to ...), an unknown property name, a write to a read-only property, an out-of-range integer, or an object of the wrong class.
Names are Chilkat's in snake_case: QuickGetStr is quick_get_str, LastErrorText is last_error_text. Properties are fields (dt_obj.verbose_logging = true) and methods use the colon (dt_obj:method(...)). Strings are UTF-8; binary data is a Lua string of bytes. Indexes are 0-based, as in every Chilkat API. Unlocking: call chilkat.unlock_bundle("...") once at startup.
Properties
Day
local intVal = dt_obj.day
dt_obj.day = intVal
The day of the month. The valid values for this member are 1 through 31.
topDebugLogFilePath
local strVal = dt_obj.debug_log_file_path
dt_obj.debug_log_file_path = strVal
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
Hour
local intVal = dt_obj.hour
dt_obj.hour = intVal
The hour. The valid values for this member are 0 through 23.
topLastErrorHtml
local strVal = dt_obj.last_error_html
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
local strVal = dt_obj.last_error_text
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
local strVal = dt_obj.last_error_xml
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
local boolVal = dt_obj.last_method_success
dt_obj.last_method_success = boolVal
Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
Minute
local intVal = dt_obj.minute
dt_obj.minute = intVal
The minute. The valid values for this member are 0 through 59.
topMonth
local intVal = dt_obj.month
dt_obj.month = intVal
The month. The valid values for this member are 1 through 12 where 1 = January and 12 = December.
topSecond
local intVal = dt_obj.second
dt_obj.second = intVal
The second. The valid values for this member are 0 through 59.
topStructTmMonth
local intVal = dt_obj.struct_tm_month
dt_obj.struct_tm_month = intVal
The month. The valid values for this member are 0 through 11 where 0 = January and 11 = December.
topStructTmYear
local intVal = dt_obj.struct_tm_year
dt_obj.struct_tm_year = intVal
The year represented as the number of years since 1900.
topUtc
local boolVal = dt_obj.utc
dt_obj.utc = boolVal
true if this is a UTC time, otherwise false if this is a local time.
VerboseLogging
local boolVal = dt_obj.verbose_logging
dt_obj.verbose_logging = boolVal
If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
local strVal = dt_obj.version
Year
local intVal = dt_obj.year
dt_obj.year = intVal
The year, such as 2012.
topMethods
DeSerialize
dt_obj:de_serialize(serialized_dt_obj)
Loads the date/time with a string having the format as produced by the Serialize method, which is a string of SPACE separated integers containing (in this order) year, month, day, hour, minutes, seconds, and a UTC flag having the value of 1/0.
topSerialize
local str, err = dt_obj:serialize()
Serializes the date/time to a us-ascii string that can be imported at a later time via the DeSerialize method. The format of the string returned by this method is not intended to match any published standard. It is formatted to a string with SPACE separated integers containing (in this order) year, month, day, hour, minutes, seconds, and a UTC flag having the value of 1/0.
Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.