Generic data type

• 7 minutes to read

Generic is the base type of all other intrinsic CRMScript data types. Any variable can be up-casted to Generic.

There's a close connection between Generic and structs:

simpler iteration of variables (struct members)
easier to access and set new variables in structs
possible to change which variables are members without having to hard-code each field

By using this datatype, especially with structs, you can limit the amount of code. You won't have to create as many duplicate functions to handle different types - simply place all logic inside 1 function and let it act accordingly to the type.

Note

You can create arrays of any data type to store more than one value at the same time like this: String[] s1;. For a given array, all items must be of the same type. Read more about looping and accessing array items in the fundamentals section.

Type and value

String getTypeName(Generic generic)

getTypeName() returns the type of a variable.

printLine(getTypeName(getCurrentDateTime()));

Generic getGenericValue(String name)

getGenericValue() returns a variable from the run-time environment given its name and independent of its type.

Integer age = 42;
Generic g = getGenericValue("age");
printLine(GenericToInteger(g).toString());

Note

If the variable name is unknown, an exceptions is thrown.

Down-casting

You can convert a Generic variable to these basic types.

Bool GenericToBool(Generic generic)
Integer GenericToInteger(Generic generic)
Float GenericToFloat(Generic generic)
String GenericToString(Generic generic)
DateTime GenericToDateTime(Generic generic)
Date GenericToDate(Generic generic)
Time GenericToTime(Generic generic)
TimeSpan GenericToTimeSpan(Generic generic)
Byte GenericToByte(Generic generic)
Generic[] GenericToArray(Generic generic)

Together with getTypeName(), these methods can be used to create an explicit typed variable.

Generic g = getCurrentDateTime();
if (getTypeName(g) == "DateTime") {
  DateTime dt = GenericToDateTime(g);
}

Generic and arrays

Integer getTypeDimensions(Generic generic)

getTypeDimensions() returns the number of array dimensions for a variable. The argument is automatically up-casted to a Generic.

Integer[][] i;
printLine(getTypeDimensions(i).toString());

Note

This is the number of dimensions in, not the length of, the array!

Generic and structs

The following examples build on this Person struct:

struct Person {
  String name;
  Integer age;
};

Bool typeIsStruct(Generic generic)

typeIsStruct() checks whether a variable is a struct.

Check whether a variable is a struct or not. The argument is automatically up-casted to a Generic.

struct Person {
  String name;
  Integer age;
};

Person p;
if (typeIsStruct(p)) {
  printLine("10-4");
}

String[] getStructMembers(String name)

getStructMembers() returns the variable names of a struct given its name.

Note

This is the names, not the actual values. To get those, call getGenericValue() using the member names.

struct Person {
  String name;
  Integer age;
};

Person p;

String[] members = getStructMembers(getTypeName(p));

foreach (String s in members) {
  printLine(s);
}

Generic getGenericValue(Generic struct, String name)

A variant of getGenericValue() that returns a variable from the run-time environment inside a struct given its name and independent of its type.

Person p;
p.age = 42;
Generic g = getGenericValue(p, "age");

Note

If the variable name is unknown or you're not referencing a struct, an exceptions is thrown.

String convertGenericToString(Generic generic)

convertGenericToString() returns the string representation of a variable. The argument is automatically be up-casted to a Generic.

This works for all basic types. Complex types might can't be serialized as easy, and might not support this conversion. In that case, they'll return "[complex]".

Integer age = 42;
String s = convertGenericToString(age);
printLine(s);

Void setGenericFromString(Generic generic, String value)

setGenericFromString() sets the value of a variable from a string.

It supports only basic types. Attempting to set an array or a complex type will throw an exception.

The value must be formatted according to the constructor of that type. Specifically, Date, DateTime, and Time must be on the YYYY-MM-DD HH:MI:SS format.

Tip

In combination with getStructMembers() and getGenericValue(), this function can be used to iterate a struct and set all its members programmatically instead of having to explicit hard-code each of them.

Print contents of struct for extra table

In this scenario, we've created an extra table called Building. It has multiple extra fields of different types.

Struct Building {
  Integer id;
  String name;
  String address;
  Date acquired;
  Date next_service;
  Integer floors;
  Bool has_janitor;
  Bool is_rented;
  Float value;
  Time opens;
  Time closes;
};

So instead of defining a print() method in the struct, with 1 printLine() for every member, and manually converting each value to a string like this:

Void print() {
  printLine("id: " + this.id.toString());
  printLine("name: " + this.name);
  //...
  printLine("value: " + this.value.toString(2));
  //...
}

You can define a printGeneric() method and leverage the Generic struct methods:

Void printGeneric() {
  String[] members = getStructMembers("Building");
  foreach(String field in members) {
    Generic g = getGenericValue(this, field);
    printLine(field + ": " + convertGenericToString(g));
  }
}

Parse from Json to Struct

In this scenario, still using our Building extra table, we'd like to to parse from Json into a struct.

Without Generic:

Building Building(String json) {
  Building b;
  XMLNode root = parseJSON(json);

  b.id = root.getValueFromPath("id").toInteger();
  b.name = root.getValueFromPath("name");
  //...
  b.is_rented = root.getValueFromPath("is_rented").toBool();
  b.value = root.getValueFromPath("id").toFloat();
  //...
  return b;
}

With Generic:

Building BuildingGeneric(String json) {
  Building b;
  XMLNode root = parseJSON(json);

  String[] members = getStructMembers("Building");

  foreach(String field in members) {
    Generic g = getGenericValue(b, field);
    String value = root.getValueFromPath(field);
    setGenericFromString(g, value);
  }
  
  return b;
}

Notice how this method doesn't have to know anything about the Building table. No variable names, no data types, and not even how many there are.

Load from database to Struct

In this scenario, still using our Building extra table, we'd like to load data from the database into a struct.

Without Generic:

Building Building(Integer id) {
  Building b;
  
  SearchEngine se;
  se.addField("y_building.id");
  //...
  
  se.addCriteria("y_building.id", "Equals", id.toString());
  se.execute();
  
  if(!se.eof()) {
    b.id = se.getField("y_building.id").toInteger();
    //...
  }
  
  return b;
}

With Generic:

Building BuildingGeneric(Integer id) {
  Building b;
  SearchEngine se;
  String[] members = getStructMembers("Building");
  
  foreach(String field in members) {
    se.addField("y_building." + extraFieldName(field));
    se.addCriteria("y_building.id", "Equals", id.toString());
    se.execute();
  }  
  
  if(!se.eof()) {
    foreach(String field in members) {
      Generic g = getGenericValue(b, field);
      String value = se.getField("y_building." + extraFieldName(field));
      setGenericFromString(g, value);  
    }
  }
  return b;
}