Specifications

An Address Book Reader
5-35
Check_And_Load Code Listing
This is the Check_And_Load function.
function pass = Check_And_Load(file,handles)
% Initialize the variable "pass" to determine if this is a valid
% file.
pass = 0;
% If called without any file then set file to the default file
% name.
% Otherwise if the file exists then load it.
if isempty(file)
file = 'addrbook.mat';
handles.LastFile = file;
guidata(handles.Address_Book,handles)
end
if exist(file) == 2
data = load(file);
end
% Validate the MAT-file
% The file is valid if the variable is called "Addresses" and it
% has fields called "Name" and "Phone"
flds = fieldnames(data);
if (length(flds) == 1) & (strcmp(flds{1},'Addresses'))
fields = fieldnames(data.Addresses);
if (length(fields) == 2) &(strcmp(fields{1},'Name')) &
(strcmp(fields{2},'Phone'))
pass = 1;
end
end
% If the file is valid, display it
if pass
% Add Addresses to the handles structure
handles.Addresses = data.Addresses;
guidata(handles.Address_Book,handles)
% Display the first entry
set(handles.Contact_Name,'String',data.Addresses(1).Name)
set(handles.Contact_Phone,'String',data.Addresses(1).Phone)
% Set the index pointer to 1 and save handles
handles.Index = 1;
guidata(handles.Address_Book,handles)