Recognition: Advanced Topics

Using Advanced Topics in Recognition

The cells in this example template use filters defined by the

format

and

filters

slots to restrict input to valid values.

The

format

slot specifies the valid input for each position in the comb view. Each

character in the

format

string is an index into the

filters

array. In this example,

the first position in the comb view is filtered by the element 1 of the

filters

array, which is the

digits1

template; the second position is filtered by element 0

of the filters array, which is the

digits

template.

You can write-protect any position in the comb view by placing an underscore (

_

)

in the appropriate position in the

format

string. In this example, the string positions

that display slashes between the digits of the date field do not allow input. These
are indicated by the underscores at corresponding positions in the

format

string.

The

text

slot is not used by

protoCharEdit

views, but may be used as a

default value by optional

SetupString

and

CleanupString

methods that your

template supplies.

Note that the template itself does not restrict any values unnecessarily. For example,
it is not wise to restrict date values according to the value of the month, because the
user might enter the date before the month or the month value might not be
recognized correctly. Instead, you can define a

CleanupString

function that

examines the input string and indicates an error condition or modifies the string.

The following code fragment provides examples of typical

SetupString

and

CleanupString

functions.

myTemplate := {

format:"0000001",
string:" 0",
filters: [kMyDigitsOrSpace, kMyDigits],

SetupString: func(str) begin

// pad string to 5 digits
if StrLen(str) < 7 then

StrMunger(str,0,0,string,0,7-StrLen(str));

str;

end,

CleanupString: func(str) begin

// replace spaces with zeros
StrReplace(str, " ", "0", nil);
// trim leading zeros
str := NumberStr(StringToNumber(str));
str;

end,

};