Saving and Restoring Data, Using Properties. - Revision history

Danny252: Add reference links, add navigation links

2020-12-28T14:45:58Z

Add reference links, add navigation links

Tonyhilliam at 02:06, 17 January 2018

2018-01-17T02:06:40Z

← Older revision		Revision as of 02:06, 17 January 2018
Line 104:		Line 104:

	Previous Tutorial: [[Talking_to_Yourself,_Sending_Messages.]] Next Tutorial: [[Setting Up the Asset.]]<br>		Previous Tutorial: [[Talking_to_Yourself,_Sending_Messages.]] Next Tutorial: [[Setting Up the Asset.]]<br>

			[[Getting_Started_in_TrainzScript\|Back to Getting Started]]

Mjolnir: /* Added link to previous tutorial */

2016-05-31T06:04:48Z

Added link to previous tutorial

← Older revision		Revision as of 06:04, 31 May 2016
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	You have now used the most important of the standard method calls and learned how to send messages and how to save and retrieve data. Now we can move on to creating an asset and making it do something useful.<br><br>		You have now used the most important of the standard method calls and learned how to send messages and how to save and retrieve data. Now we can move on to creating an asset and making it do something useful.<br><br>

	Next Tutorial: [[Setting Up the Asset.]]<br>		Previous Tutorial: [[Talking_to_Yourself,_Sending_Messages.]] Next Tutorial: [[Setting Up the Asset.]]<br>

Andi06 at 23:11, 24 April 2013

2013-04-24T23:11:53Z

← Older revision		Revision as of 23:11, 24 April 2013
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	Then = "\nLast time we met was in the " + Then;		Then = "\nLast time we met was in the " + Then;
	}		}
	Exception("Hello World, " + msg.minor + Then + "\n\n");		Interface.ShowPopupHelp("Hello World, " + msg.minor,GetAsset(),Interface.GetTimeStamp())
			//Exception("Hello World, " + msg.minor + Then + "\n\n");// use this in old versions
	}		}

Line 86:		Line 87:
	'''''ReminderHandler'''''		'''''ReminderHandler'''''
	* This method has been amended to look at the value of the global variable ''Then'' which has been retrieved from the session files via the ''SetProperties()'' method.		* This method has been amended to look at the value of the global variable ''Then'' which has been retrieved from the session files via the ''SetProperties()'' method.
	* If the value of ''Then'' is not an empty string it is chopped and formatted so that it can be included in our ''Exception()'' message.<br>		* If the value of ''Then'' is not an empty string it is chopped and formatted so that it can be included in our ''ShowPopupHelp()'' or ''Exception()'' message.<br>

	To test this out:		To test this out:
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	* Place a copy of your object, wait for the message which will be the same as before.		* Place a copy of your object, wait for the message which will be the same as before.
	* Quit the map making sure to save the Surveyor session.		* Quit the map making sure to save the Surveyor session.
	* Reload and wait for the ~~''Exception()''~~ message.		* Reload and wait for the message.
	* This time it should look like this:<br><br>		* This time it should look like this:<br><br>

Windwalkr: 1 revision

2010-02-03T13:59:41Z

1 revision

← Older revision	Revision as of 13:59, 3 February 2010
(No difference)

Andi06: /* Saving and Restoring Data, Using Properties */

2008-07-11T22:55:19Z

Saving and Restoring Data, Using Properties

New page

Apart from ''Init()'' there are several other standard methods which you can include which will be called at the appropriate time by the game. Two of the most important are ''GetProperties()'' which is called when Trainz needs to retrieve any useful data which your object might wish to save to the session file, and ''SetProperties()'' which is called when your object might want to read or update any data which has been saved by the game.

* ''SetProperties()'' is called at the start of a Surveyor or Driver session and whenever the Object Property dialogue is saved. It is also used by the Undo system.
* ''GetProperties()'' is called when the Object Property dialogue is opened and when the current session is saved and exited.

To demonstrate this we have a further script:

include "MapObject.gs"

class Tutorial isclass MapObject {

string Now;
string Then;

string GetTime(float GameTime) {
string result = "Good Afternoon";
if (GameTime >= 0.25) result = "Good Evening";
if (GameTime >= 0.5) result = "Good Morning";
return result;
}

public void Init(void) {
inherited();
Now = GetTime(World.GetGameTime());
AddHandler(me,"Reminder","","ReminderHandler");
PostMessage(me,"Reminder",Now,5.0);
}

public void SetProperties(Soup soup) {
inherited(soup);
Then = soup.GetNamedTag("last");
}

public Soup GetProperties(void) {
Soup soup = inherited();
soup.SetNamedTag("last",Now);
return soup;
}

void ReminderHandler(Message msg) {
if (Then != "") {
Str.TrimLeft(Then,"Good ");
Then = "\nLast time we met was in the " + Then;
}
Exception("Hello World, " + msg.minor + Then + "\n\n");
}

};

'''''string Now;''''' 
'''''string Then;''''' 
* The declaration of ''Now'' has been moved from ''Init()'' to the body of the script.
* A second declaration, ''Then'' has been added in the same place.
* Declaring them here makes them ''global'', meaning that they can be used by any method within the script.

'''''public void SetProperties(Soup soup) {''''' 
* This is the standard declaration of ''SetProperties()''
* The method is public, since it needs to be called from outside the current script.
* It requires one parameter of type Soup (a Trainz database), which is supplied by the game.
* This database contains all the data about our object which has previously been saved to disc.

'''''inherited(soup);''''' 
* As with ''Init()'' the equivalent function in the parent ''MapObject'' must be called first.
* The ''Soup'' which the game has supplied is passed on to allow the parent to extract any data that it might need.

'''''Then = soup.GetNamedTag("last");''''' 
* We need to know whether it was morning, afternoon or evening the last time that the session was saved.
* ''GetNamedTag("last")'' retrieves this data from the ''Soup'' by specifying the key that will have been used to save it.
* The first time that we place our asset the tag will not contain any data and will return an empty string.

'''''public Soup GetProperties(void) {''''' 
* This is the standard declaration of ''GetProperties''
* This is a public function which returns a ''Soup'' but requires no parameters.

'''''Soup soup = inherited();''''' 
* The equivalent function within the parent MapObject class must be called first.
* A ''Soup'' database is declared and the contents of the parent's ''Soup'' are assigned to it.

'''''soup.SetNamedTag("last",Now);''''' 
* Once the parent has provided its data we need to add our own information to the database.
* We can do this by creating or updating information referenced by the tag name "last", so we set this item to be the current value of ''Now''.

'''''return soup;''''' 
* Having added our data we send the modified database back to the game to be written to disk.

'''''ReminderHandler'''''
* This method has been amended to look at the value of the global variable ''Then'' which has been retrieved from the session files via the ''SetProperties()'' method.
* If the value of ''Then'' is not an empty string it is chopped and formatted so that it can be included in our ''Exception()'' message. 

To test this out:
* Modify the script as before.
* Load TRS and start a new map in Surveyor.
* Place a copy of your object, wait for the message which will be the same as before.
* Quit the map making sure to save the Surveyor session.
* Reload and wait for the ''Exception()'' message.
* This time it should look like this: 

[[Image:The Last Time.jpg]] 

From now on every time the session is saved and reloaded your object will remember the time of day when it was last saved. Rather than just saving Morning, Afternoon and Evening we could have updated the actual game time throughout the session and used the same mechanism to save the time when the session is closed down. We could also use similar techniques to reset the clock on reloading the session.

You have now used the most important of the standard method calls and learned how to send messages and how to save and retrieve data. Now we can move on to creating an asset and making it do something useful. 

Next Tutorial: [[Setting Up the Asset.]]

← Older revision		Revision as of 14:45, 28 December 2020
Line 1:		Line 1:
	Apart from ''Init()'' there are several other standard methods which you can include which will be called at the appropriate time by the game. Two of the most important are ''GetProperties()'' which is called when Trainz needs to retrieve any useful data which your object might wish to save to the session file, and ''SetProperties()'' which is called when your object might want to read or update any data which has been saved by the game.		Apart from ''Init()'' there are several other standard methods which you can include which will be called at the appropriate time by the game. Two of the most important are ''GetProperties()'' which is called when Trainz needs to retrieve any useful data which your object might wish to save to the session file, and ''SetProperties()'' which is called when your object might want to read or update any data which has been saved by the game.

	* ''SetProperties()'' is called at the start of a Surveyor or Driver session and whenever the Object Property dialogue is saved. It is also used by the Undo system.		* ''[[Class PropertyObject#SetProperties\|SetProperties]]()'' is called at the start of a Surveyor or Driver session and whenever the Object Property dialogue is saved. It is also used by the Undo system.
	* ''GetProperties()'' is called when the Object Property dialogue is opened and when the current session is saved and exited.		* ''[[Class PropertyObject#GetPropertirs\|GetProperties]]()'' is called when the Object Property dialogue is opened and when the current session is saved and exited.

	To demonstrate this we have a further script:		To demonstrate this we have a further script:
Line 55:		Line 55:
	* Declaring them here makes them ''global'', meaning that they can be used by any method within the script.		* Declaring them here makes them ''global'', meaning that they can be used by any method within the script.

	'''''public void SetProperties(Soup soup) {'''''<br>		'''''public void SetProperties([[Class Soup\|Soup]] soup) {'''''<br>
	* This is the standard declaration of ''SetProperties()''		* This is the standard declaration of ''[[Class PropertyObject#SetProperties\|SetProperties]]()''
	* The method is public, since it needs to be called from outside the current script.		* The method is public, since it needs to be called from outside the current script.
	* It requires one parameter of type Soup (a Trainz database), which is supplied by the game.		* It requires one parameter of type [[Class Soup\|Soup]] (a Trainz database), which is supplied by the game.
	* This database contains all the data about our object which has previously been saved to disc.		* This database contains all the data about our object which has previously been saved to disc.

	'''''inherited(soup);'''''<br>		'''''inherited(soup);'''''<br>
	* As with ''Init()'' the equivalent function in the parent ''MapObject'' must be called first.		* As with ''Init()'' the equivalent function in the parent ''[[Class MapObject\|MapObject]]'' must be called first.
	* The ''Soup'' which the game has supplied is passed on to allow the parent to extract any data that it might need.		* The ''Soup'' which the game has supplied is passed on to allow the parent to extract any data that it might need.

	'''''Then = soup.GetNamedTag("last");'''''<br>		'''''Then = soup.[[Class Soup#GetNamedTag\|GetNamedTag]]("last");'''''<br>
	* We need to know whether it was morning, afternoon or evening the last time that the session was saved.		* We need to know whether it was morning, afternoon or evening the last time that the session was saved.
	* ''GetNamedTag("last")'' retrieves this data from the ''Soup'' by specifying the key that will have been used to save it.		* ''GetNamedTag("last")'' retrieves this data from the ''Soup'' by specifying the key that will have been used to save it.
	* The first time that we place our asset the tag will not contain any data and will return an empty string.		* The first time that we place our asset the tag will not contain any data and will return an empty string.

	'''''public Soup GetProperties(void) {'''''<br>		'''''public [[Class Soup\|Soup]] GetProperties(void) {'''''<br>
	* This is the standard declaration of ''GetProperties''		* This is the standard declaration of ''[[Class PropertyObject#GetProperties\|GetProperties]]()''
	* This is a public function which returns a ''Soup'' but requires no parameters.		* This is a public function which returns a ''Soup'' but requires no parameters.

Line 78:		Line 78:
	* A ''Soup'' database is declared and the contents of the parent's ''Soup'' are assigned to it.		* A ''Soup'' database is declared and the contents of the parent's ''Soup'' are assigned to it.

	'''''soup.SetNamedTag("last",Now);'''''<br>		'''''soup.[[Class Soup#SetNamedTag\|SetNamedTag]]("last",Now);'''''<br>
	* Once the parent has provided its data we need to add our own information to the database.		* Once the parent has provided its data we need to add our own information to the database.
	* We can do this by creating or updating information referenced by the tag name "last", so we set this item to be the current value of ''Now''.		* We can do this by creating or updating information referenced by the tag name "last", so we set this item to be the current value of ''Now''.
Line 101:		Line 101:
	From now on every time the session is saved and reloaded your object will remember the time of day when it was last saved. Rather than just saving Morning, Afternoon and Evening we could have updated the actual game time throughout the session and used the same mechanism to save the time when the session is closed down. We could also use similar techniques to reset the clock on reloading the session.		From now on every time the session is saved and reloaded your object will remember the time of day when it was last saved. Rather than just saving Morning, Afternoon and Evening we could have updated the actual game time throughout the session and used the same mechanism to save the time when the session is closed down. We could also use similar techniques to reset the clock on reloading the session.

	You have now used the most important of the standard method calls and learned how to send messages and how to save and retrieve data. Now we can move on to creating an asset and making it do something useful.~~<br><br>~~		You have now used the most important of the standard method calls and learned how to send messages and how to save and retrieve data. Now we can move on to creating an asset and making it do something useful.

	~~Previous Tutorial: [[Talking_to_Yourself,_Sending_Messages.]] Next Tutorial: [[Setting Up the Asset.]]<br>~~		== Navigation ==

	[[~~Getting_Started_in_TrainzScript\|~~Back to Getting Started]]		* Previous Tutorial: [[Talking to Yourself, Sending Messages.]]
			* Next Tutorial: [[Setting Up the Asset.]]
			* Back to [[Getting Started in TrainzScript]]