Getting DataFileElement name

[xeon]

Hi, a little problem for you. I want to get a DataFileElement name. For example, if I have a variable myvar which have assigned a DataFileElement like this

Code: Select all

Element myelement
{
	CProp1 sValue1
	CProp2 sValue2
}

How can I get "myelement" from the variable myvar?

[esdete]

If you put some datafileelemenet reference to the 'myvar' you should have the informaction about name of that element.
If it is imposible, you have to check all elements in datafile and compare with your reference.

[xeon]

I was afraid that the answer would have been something like that :/

Yes, I can retrieve the id of the element, but this complicates the code because you cannot have abstract functions like

Code: Select all

...
var oDatafile := OpenDatafile(...);
var oSomeObject := <some function which return some object>;
var myvar := GetRelatedDataFileElement(oDatafile, oSomeObject);
...

that is, hiding the datafile element index retrieving part in the GetRelatedDataFileElement() function.

Yes, not an insurmountable problem, but I think that you should be able to retrieve the index value of a DataFileElement directly from it.

Maybe I should file a feature request...?

[Austin]

To use a datafile and get the elem, you already had to know the name of it.
This is from the distro and helps a lot in using a data file. There is also a datafile_ex with functions to convert between data files to configs and vice-versa.

If you just wanted to pass a datafile elem to a function to handle it, one option would be something like

Code: Select all

var pass_this := struct;
pass_this.+elemname := elem_name;
pass_this.+dataelem := datafile_elem;

SomeFunction(pass_this);

Code: Select all

/* $Id: datafile.inc 161 2009-07-24 20:19:21Z AustinHeilman $
 *
 * Purpose
 * TODO
 *
 * Function List *
 * DFFindElement(byref file_ref, elem_name, create)
 * DFGetElemNames(byref file_ref)
 * DFGetElemProps(elem_ref)
 * DFGetProp(byref elem_ref, prop_name, create, assign_val)
 * DFOpenDataFile(file_name, create, flags)
 * CfgToDF(cfg_name, df_name, propnames)
 * DFToCfg(df_name, cfg_name)
 *
 * Private Function List *
 * DF_OutPut(text)
 *
 * Global Variables *
 * Datafile.em CONSTants
 * CONST DF_KEYTYPE_STRING       := 0x00; // default
 * CONST DF_KEYTYPE_INTEGER      := 0x01;
 *
 */
use uo;
use os;
use file;
use basic;
use cfgfile;
use datafile;

// Determines if a file or elem will be created when a read attempt is made.
CONST DF_NO_CREATE	:= 0;
CONST DF_CREATE		:= 1;

// Set to 1 in your script to turn on the logging calls.
var DF_DEBUG_MODE	:= 0;


/*
 * DFOpenDataFile(filename, create, flags)
 *
 * Purpose
 * Creates a datafile handler.
 *
 * Parameters
 * filename:	Path and name of the data file. (Example ":pkg-name:file-name")
 * create:	Creation flags:
 *		DF_NO_CREATE	Will return an error if the datafile does not exist. *Default
 *		DF_CREATE	Will create the datafile if it does not exist.
 * flags:	Datafile.em flags:
 *		DF_KEYTYPE_STRING	Elem names will be handled as strings.
 *		DF_KEYTYPE_INTEGER	Elem names will be handled as integers.
 *
 * Return value
 * A datafile reference.
 *
 */
function DFOpenDataFile(file_name, create:=DF_NO_CREATE, flags:=DF_KEYTYPE_STRING)
	var data_file := OpenDataFile(file_name);
	if ( (!data_file) && (create) )
		DF_OutPut("Debug::DFOpenDataFile() - Creating data file: "+file_name);
		CreateDataFile(file_name, flags);
		data_file := OpenDataFile(file_name);
	endif

	if ( data_file )
		return data_file;
	elseif ( create )
		var errmsg := error{"errortext":="Error::DFOpenDataFile() - Could not open "+file_name+" : "+data_file.errortext};
		DF_OutPut(errmsg.errortext);
		return errmsg;
	endif
endfunction

/*
 * DFPurgeFile(byref file_ref)
 *
 * Purpose
 * Erases all elems in a datafile. (WIPES IT CLEAN)
 *
 * Parameters
 * file_ref:	The datafile to wipe.
 *
 * Return value
 * Returns 1
 *
 */
function DFPurgeFile(byref file_ref)
	foreach elem_name in ( DFGetElemNames(file_ref) )
		file_ref.DeleteElement(elem_name);
		SleepMS(2);
	endforeach

	return 1;
endfunction

/*
 * DFGetElemNames(byref file_ref)
 *
 * Purpose
 * Retrieves a list of all elem names that are in a data file.
 *
 * Parameters
 * file_ref:	The datafile to retrieve the elem names in.
 *
 * Return value
 * An array of strings or integers.
 *
 */
function DFGetElemNames(byref file_ref)
	var elem_keys := file_ref.Keys();
	if ( elem_keys == error )
		var errmsg := error{"errortext":="Error::DFGetElemNames() - Could not return elem keys :"+elem_keys.errortext};
		DF_OutPut(errmsg.errortext);
		return errmsg;
	else
		return elem_keys;
	endif
endfunction


/*
 * DFFindElement(byref file_ref, elem_name, create)
 *
 * Purpose
 * Creates a datafile elem handler.
 *
 * Parameters
 * file_ref:	Data file to retrieve/create the element in.
 * elem_name:	Name of the element to retrieve.
 * create:	Creation flags:
 *		DF_NO_CREATE	Will return an error if the data elem does not exist. *Default
 *		DF_CREATE	Will create the data elem if it does not exist.
 *
 * Return value
 * A data file element reference.
 *
 */
function DFFindElement(byref file_ref, elem_name, create:=DF_NO_CREATE)
	var temp := file_ref.FindElement(CStr(elem_name));
	if ( !temp && create )
		DF_OutPut("Debug::DFFindElement() - Creating elem: "+CStr(elem_name));
		file_ref.CreateElement(CStr(elem_name));
		temp := file_ref.FindElement(CStr(elem_name));
	endif

	if ( temp )
		return temp;
	elseif (create)
		var errmsg := error{"errortext":="Error::DFFindElement() - Could not open data elem ["+elem_name+"] - "+temp.errortext};
		DF_OutPut(errmsg.errortext);
		return errmsg;
	endif
endfunction


/*
 * DFGetElemProps(byref elem_ref)
 *
 * Purpose
 * Retrieves a list of all prop names that are in a data elem.
 *
 * Parameters
 * elem_ref:	The data elem to retrieve the property names in.
 *
 * Return value
 * An array of strings.
 *
 */
function DFGetElemProps(elem_ref)
	var prop_names := elem_ref.PropNames();
	if ( prop_names == error )
		var errmsg := error{"errortext":="Error::DFGetElemProps() - Could not return prop names :"+prop_names.errortext};
		DF_OutPut(errmsg.errortext);
		return errmsg;
	else
		return prop_names;
	endif
endfunction


/*
 * DFGetProp(byref elem_ref, prop_name, create, assign_val)
 *
 * Purpose
 * Retrieves the information in a cprop, or assigns it a value if told to do-so.
 *
 * Parameters
 * elem_ref:	The data elem to retrieve the property from.
 * prop_name:	The name of the property to retrieve.
 * create:	Creation flags:
 *		DF_NO_CREATE	Will return an error if the property does not exist. *Default
 *		DF_CREATE	Will create the property if it does not exist and an assign value is set.
 * assign_val:	Value to set the property to if it is created.
 *
 * Return value
 * The value of the property.
 *
 */
function DFGetProp(byref elem_ref, prop_name, create:=DF_NO_CREATE, assign_val:=0)
	var temp := elem_ref.GetProp(prop_name);

	if ( (temp==error) && (create) )
		elem_ref.SetProp(prop_name, assign_val);
		temp := elem_ref.GetProp(prop_name);
	endif

	if ( temp || (create) && (!assign_val) )
		// Second case is for creating and returning
		// what ever you get. Used for cases where the
		// value is '0' but not an error.
		return temp;
	elseif ( create )
		var errmsg := error{"errortext":="Error::DFGetProp() - Could not read data file property "+prop_name+":"+temp.errortext};
		DF_OutPut(errmsg.errortext);
		return errmsg;
	endif
endfunction


/*
 * DF_OutPut(text)
 *
 * Purpose
 * Internal function that is used to control system logging.
 *
 * Parameters
 * text:	Text to log.
 *
 * Return value
 * Returns 1
 *
 */
function DF_OutPut(text)
	if ( DF_DEBUG_MODE )
		//SysLog(text);
		var script_name := GetProcess(GetPid()).name;
		LogToFile("::log/dataFile.log", "["+script_name+"]: "+text, LOG_DATETIME);
	endif

	return 1;
endfunction

[xeon]

Thank you for your answer Austin,

...
If you just wanted to pass a datafile elem to a function to handle it, one option would be something like

Code: Select all

var pass_this := struct;
pass_this.+elemname := elem_name;
pass_this.+dataelem := datafile_elem;

SomeFunction(pass_this);

...

That's surely a welcome idea, and a cleaner one than mine. I was adding an optional byref parameter to the function which retrieve my DataFileEleme, so I'm doing it like this:

Code: Select all

var oDatafile := OpenDatafile(...);
var sIndex := "";
var oSomeObject := GetRelatedDataFileElement(oDatafile, oSomeObject, sIndex);
...
function GetRelatedDataFileElement(oDatafile, oSomeObject, byref sIndex)
...

And yes, I've seen the distro include to handle Datafile, very useful, but on our shard we're using our own, which anyway it's much similar but free us from distro sourcebase.

[Austin]

Ill put it on a to-do list.. to add properties to the datafile objects, its quite a bit of work though.

[xeon]

You're the best.