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Difference between revisions of "EDT:Code snippets"

(Declaring data)
(Declaring data)
Line 13: Line 13:
 
:simple reference types:
 
:simple reference types:
  
::Bytes, Decimal, Number, String (now a value type, String(''n''), Timestamp (now a value type)  
+
::Bytes, Decimal, Number, String (now a value type, String(''n''),  
 +
 
 +
::Timestamp (now a value type)  
  
 
'''Variables'''  
 
'''Variables'''  

Revision as of 15:37, 7 February 2012

Please share your code snippets!

Declaring data

Native types:

simple value types:
BigInt, Bytes(n), Date, Decimal(n), Decimal(n, p),
Float, Int, SmallFloat, SmallInt, Timestamp(pattern)
simple reference types:
Bytes, Decimal, Number, String (now a value type, String(n),
Timestamp (now a value type)

Variables

// defaults to 0
someVal Int;                
 
// defaults to null.
someVal Int?;      
 
// initializes value to 15 (future value can be null).         
someVal Int? = 15;          
 
// initializes value to 23.
someVal Int = 23;           
 
// defaults to "".
firstName String;
 
// defaults to null.           
firstName String?; 
 
// initializes value to "John".         
firstName String = "John";  
 
// defaults to 0.
largeVal Bigint;
 
// number with 5 total digits (2 after the decimal point). Defaults to 000.00.            
amount Decimal(5,2);        
 
// defaults to 0.0.
coord Float;       
 
// defaults to false         
toggle Boolean;             
 
// defaults to today's date.
dob Date;    
 
// defaults to the current timestamp.
ts Timestamp?;
 
// value can be set to any value (primitive, object, etc). See the casting examples later.
x Any?;

Lists

vals Int[];                // new dynamic array of size 0
vals Int[]?;               // dynamic list, but not instantiated (vals must be instantiated before it can be accessed)
vals Int[] = new Int[4];   // new dynamic array of size 4; all values set to their default value (0 in this example)
 
names String[] = [ "Paul", "John", "George", "Ringo" ];   // dynamic array, initialized with 4 values
names[1] = "Bob";                                         // assigns the first index in the array to "Bob"
names[names.getSize()] = "Ken";                           // assigns the last index in the array to "Ken"
 
cities String[];                           // new dynamic array of size 0
cities.appendElement("Delta");             // appends a new value to the end of the array
cities.appendAll([ "Denver", "Pueblo" ]);  // appends two new values to the end of the list cities.removeElement(2);                   // removes the second value in the array 
cities.removeAll();                        // removes all values from the array


Constants

// The value is not changeable.
const NUMBEROFDAYS Int = 7;
 
// The element values are changeable, but the name cannot refer to another list.
const MINIMUMNUMBERS INT[] = [1,2,3,4,5];





Rich UI

Services

Calling a REST service

http HttpRest{request.uri="http:host\\myService"};
srvc IRest?;
srvc = ServiceLib.completeBind(srvc, http);

Accessing HTTP request headers

http HttpRest{};
http.request.headers = new Dictionary { param1 = "a value to pass to my service" };
srvc IRest?{@Resource {}};
srvc = ServiceLib.completeBind(srvc, http);

HTTP request and response

function invokeDoSomething()
    call srvc.doSomething() returning to serviceCallback;
end
 
function serviceCallback(returnValueOne String, callbackHttp IHTTP in)
  // process callback request or response
end

Database access

Defining a record

record CUSTOMER type Entity{@table{name = "CUSTOMER"}}   // record is bound to the CUSTOMER table (or view)
    CUSTID string{@id};                                  // primary key field
    NAME string;        
    COUNTRY string;
    STATE string?;                                       // nullable field   
end

Getting a record

function getCustomer(someId String in} returns (Customer)
    ds SQLDataSource?{@resource {}};                       // declares a data source that will use binding name "ds" (since a name is not specified)
 
    aCust Customer;                                        // declares and empty customer record
    get aCust from ds using(someId);                       // gets the record in the table that has a key value of someID and populates the customer record
 
    get aCust from ds using(someId) with #sql{             // alternative approach for getting a single record (allows for customizing the SQL)
	SELECT *
	FROM CUSTOMER
	WHERE id = ?
    };
 
    vals Dictionary;                                       // declares a new dictionary
    get vals from ds using(someId) with #sql{              // alternative approach for getting a single record (does not require a Record definition)
	SELECT *
	FROM CUSTOMER
	WHERE id = ?
     };                                                    // creates a key/value pair in the dictionary for each column in the result set
 
    return (aCust);
end
Getting multiple records
function getCustomer(} returns (Customer[])
    ds SQLDataSource?{@resource {}};                       // declares a data source that will use binding name "ds" (since a name is not specified)
 
    custs Customer[];                                      // declares a new dynamic array of customer records
    get custs from ds;                                     // populates the array with a Customer record for each row in the result set
 
    get custs from ds with #sql {
       select * from customer where state = 'CO'
    };                                                     // populates the array, but with a limited set of Customer records
 
    state String = "CO";
    get custs from ds using(state) with #sql {
       select * from customer where state = ?
    };                                                     // parameterized version of the previous example
 
 
end

Inserting a record

function addCustomer{customer Customer in}
    ds SQLDataSource?{@resource {}};
    add customer to ds;
end

Looping through a SQL result set

 function loopCust()
     ds SQLDataSource?{@resource{uri = "binding:myDB" }};       // declares a new data source 
     rs SQLResultSet?;                                          // declares a new result set
 
     open rs from ds with #sql{                                 // opens a result set using the specified SQL query
	SELECT * FROM CUSTOMER
     };
 
     myCust Customer;
 
     //Loop through results and write out customer name
     while(rs.getNext())
        get myCust from rs;
        Syslib.writeStdOut ("Customer name: " + myCust.name);
     end
 
 end


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