Flash MX 2004 Games : Art to ActionScript

Flash MX 2004 Games
55 break;
56 case 9:
57 str = "October ";
58 break;
59 case 10:
60 str = "November ";
61 break;
62 case 11:
63 str = "December ";
64 break;
65
66
}
67
68
d = expdate.getDate();
69 if (d
return str;
Listing 21.4
Shared objects for persistent data
A great feature of Flash MX 2004 is the object ‘SharedObject’. This operates in a very similar
way to cookies and can be used without any external scripting. To use the SharedObject you
first create an object from the ‘getLocal’ method of the SharedObject. This takes a single string
parameter, which is the name to use for the shared data file. Unless you want to read this file
from another program then you do not need to know where the data is actually stored; on a PC it
is in the Documents and Settings folder: C:\Documents and Settings\[User Name]\Application
Data\Macromedia\Flash Player\[path to swf]\swfname.swf. In the file the data for each stored
element is saved as a string. Having created a shared object from this file, the object contains the
data in the file. If the file does not exist then the object is essentially empty. To use the object you
can use the ‘data’ property and the ‘flush’ method. The data property contains any data that you
want to store up to the file limit that is settable, but should be fairly small. In this short snippet,
we create a shared object called ‘so’ then trace the value of the data property ‘favoriteColor’; this
could be any name that you find useful. Then we assign to this property the value ‘orange’. If
the property does not exist then it is created by an assignment. Then we access the data property
‘possibleColors’. If this exists then the data will be listed in the output window and if it does not
then ‘undefined’ will be displayed. If the array is missing then we create it as a new Array and
assign values to it, then assign this array to the data property ‘possibleColors’. Finally we ensure
that the data is written to the file using SharedObject method ‘flush’. If ‘flush’ returns false then
writing to the file is prohibited by security limits or file size.
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