creativeArtie / 4DUtilities

Utilities methods for 4D

What's in this?

The actual project is located in the code. It contains several sub projects:

1. Generate documentation
2. Exception handling
3. Value assertions
4. Validation

The compiled component is located as one the Test Demo component

Generating Documentation

The documentation generation generate documents directly from the source code and get be read from 4D code Explorer -> Documentation and from the web browser.

To use it just call doc_run.

Without any additional comments, this will generates

1. Class inherance diagram
2. A list of class methods names and its parameters, return values and local value
3. Method's parameters, return values and local value, with a better hover tool tip.
4. Methods and classes that ends with an underscore is marked as "private"
5. (more to come...)

Documentation support

All documentation for the generator must starts with \\!. It can accept markdown, and even the web browser will parse it using a javascript library.

Documentation in the same line as a var or methods starts with C_ will become the documentation of the variable declared.

Hashtags

There are hashtags that can be use when documenting the code. Hashtags comment must have the following syntax:

//! #name details

This is the current list of hashtags:

Hashtag Name	Description
#author	the author of this file
#brief	the documentation to add into a class, class method, or function tooltip
#todo	the todo item, with a different file listing all of them
#abstract	that the class method is a abstract and need implementation in the subclass

Exception handling

Exceptions are logged into a table call [Exceptions]. It is also being monitored in the Storage.utils_except object.

Things it can do:

Handle 4D thrown errors

except_trapError
// Method calle on error = "except_onErrCall_" (method to handle 4D errors)

Try Catch

var $exception : cs.Exception
If (except_try(Forumla(True); ->$exception)) 
    // code if no error
Else
    // code if there is an exception 
End if

Handle exceptions not catched throw "Try Catch"

While (except_catch(->$exception))
    // code for the exception find for the current process
End while 

Check for exceptions

If (except_hasExceptions)
    // exceptions find for the current process
Else
    // no exceptions find for the current process
End if

It is also can be used for unit testing

var $test : Object
$test:=AJ_UnitTest.new("..."; Current method name)

// some tests

// assert fails if there are exceptions here
except_hasExceptions($test) 

// continue testing with a clean exception list

throws your own exceptions

except_throw("Your error message")

Monitor the exceptions

This is useful when you are using this project and want to find a 4D error.

When you are using except_trapError, if there are new 4D error, the code will not call Trace nor Abort. The ExceptionMonitor form along with the debugger will let you know when the error is being thrown.

The ExceptionMonitor form will work by clicking run form.

Validator

The validator checks the fields for optional and mandatory data. There are three base classes:

1. Validator manages a group of validations:
   • Sorts the mandatory and optional checkers
   • Loads the data into the Check object, and results into Use objects
   • Stores the results
   • Gives a summary of the results
2. Check handles a single validation:
   • Runs the vaildation
   • Stores the data needed for validating
   • Provides a template for error messages
3. Use handles a single value and its vaildation result:
   • extracts the value from form object
   • formats the form object
   • produce an error message for the user
   • stores a vaildated result for the data
   • (future) returns the form object/pointer

Check class

There are 6 subclasses for Check:

• CheckAge : checks an age between two numbers or dates
• CheckFilled : check if a field is filled
• CheckFormat : check if a format is correct
• CheckNot : checks if a validation returns false
• CheckReal : checks if a number is between two numbers
• CheckWhen : checks only if a certain condition is fulfilled

To extends the Check class, the following are required:

• add the function test() -> boolean where:
  • This.getValue() will return the value to validate
  • the return value True means vaildation passes
• add the fucntion getTemplateMessage() -> Text where the return value:
  • be phrased with the word "not" so that CheckNot message can work.
  • use $1 to indicate the location of the field name

Here are the optional methods

• if using a constructor, pass nothing to Super()
• if overriding setValue($input;Variant), Super.setValue($1) must be called

Use Class

There are 4 classes for Use:

• UseCombo : for combo box form widget
• UseField : for input form widget
• UsePhoneField : for input form widget which stores a phone number
• UseValue : for data that isn't tied to any form widgets

To extend a Use classes, the following are required:

• Function getValue() must exist to get the value
• The constructor must have Super($feildName : Text)

The following are optional but are recommanded to override

• setError($message : Text)
• setWarning($message : Text)
• setPass()

In all of these methods their super method must be called. If possible, extend the class from UseCombo and UseField which already override these methods and change the colours of the form widget.

Utilities

Paramter setting

For parameters will do several things on top of the current #DECLARE. For the best result, the structure setting "Compilation Path" should set to "All variables are typed"

• Adds a defualt value
• counts the parameters
• make sure that the required value are being filled.

To use this use the following code

#DECLARE($param1: Text; $param2: Integer; $param3 : 4D.Function)->$result : Boolean

var $count : Real
$param1:=utils_assertParameter($1; ->$count; Count parameters; "default value")
$param2:=utils_assertParameter($2; ->$count; Count parameters; 23)
$param3:=utils_assertParameter($3; ->$count; Count paramters; Formula(True))
utils_assertParameterCount($count; Count parameters)

Object variable getter

Normally if you don't know if a key exists in a object's child, you'd need to:

If (Ob is defined($object;"child"))
    If (Ob is defined($object.child; "key"))
        $value:=$object.child.key
    Else
        $value:="default"
    End if
Else
    $value:="default"
End If

With utils_getValueFromObject, you can now do this to produce the same result:

$value:=utils_getValueFromObject($object; "default"; "child"; "key")