Join us today!

twinControls · 2022-10-10T12:26:25Z

The fluent interface design pattern makes your code more readable and simple. We can think of the Fluent Interface as a concept, whereas the method chaining is an implementation. The goal of the fluent interface design is to be able to apply multiple properties to an object by connecting the methods with dots(.) instead of having to apply to each method individually. Let's say you want to initialize an axis by setting some of its properties and methods. You can achieve this using one line of code as below: fbInitAxis.Name('Conveyor_1') .Enable(TRUE) .HomePosition(0) .Speed(10) .Accel(20) .Decel(15) .BelongsTo('Gantry_1'); By making the code understandable and fluid, the fluent interface gives you the impression that you are reading a sentence. To achieve this design pattern, you would need to use method chaining. In this technique, each method returns an object and you can chain all the methods together. Let's assume we need a function block that can implement multiple math operations. To demonstrate the fluent interface and method chaining, first we will create an interface called I_Calculate and we will set the return type of each method to this interface. METHOD SetNumber : I_Calculate VAR_INPUT lNumber : LREAL; END_VAR METHOD IncreaseBy : I_Calculate VAR_INPUT lIncreaseBy : REAL; END_VAR METHOD DecreaseBy : I_Calculate VAR_INPUT lDecreaseBy : REAL; END_VAR METHOD MultiplyBy : I_Calculate VAR_INPUT lMultiplyBy : REAL; END_VAR METHOD DivideBy : I_Calculate VAR_INPUT lDivideBy : REAL; END_VAR METHOD GetResult : LREAL METHOD Clear : I_Calculate As you can see above, each math operation method is set to return the I_Calculate interface. Now we will create a function block called FB_Calculate which will implement the I_Calculate interface. FB_Calculate: FUNCTION_BLOCK FB_Calculate IMPLEMENTS I_Calculate VAR_INPUT END_VAR VAR_OUTPUT END_VAR VAR {attribute 'hide'} lResult : LREAL := 0; END_VAR Method SetNumber: METHOD SetNumber : I_Calculate VAR_INPUT lNumber : LREAL; END_VAR lResult := lNumber; SetNumber := THIS^; Method IncreaseBy: METHOD IncreaseBy : I_Calculate VAR_INPUT lIncreaseBy : REAL; END_VAR lResult := lResult + lIncreaseBy; IncreaseBy := THIS^; Method DecreaseBy: METHOD DecreaseBy : I_Calculate VAR_INPUT lDecreaseBy : REAL; END_VAR lResult := lResult - lDecreaseBy; DecreaseBy := THIS^; Method MultiplyBy: METHOD MultiplyBy : I_Calculate VAR_INPUT lMultiplyBy : REAL; END_VAR lResult := lResult * lMultiplyBy; MultiplyBy := THIS^; Method DivideBy: METHOD DivideBy : I_Calculate VAR_INPUT lDivideBy : REAL; END_VAR lResult := lResult / lDivideBy; DivideBy := THIS^; Method GetResult: METHOD GetResult : LREAL GetResult := lResult; Method Clear: METHOD Clear : I_Calculate MEMSET(destAddr:= ADR(lResult),fillByte :=0, n:=SIZEOF(lResult)); Clear := THIS^; In the MAIN program; PROGRAM MAIN VAR fMyResult : LREAL; fbCalculate : FB_Calculate; END_VAR fMyResult := fbCalculate.Clear() .SetNumber(12) .DecreaseBy(2) .IncreaseBy(3.9) .MultiplyBy(5) .DivideBy(3) .GetResult(); Everyone even non-programmers can easily grasp the code thanks to the fluent interface and method chaining.

Notifications

Clear all

Fluent Interface and Method Chaining in TwinCAT 3

Page 2 / 2 Prev

Knowledge Base

Last Post by runtimevictor 3 years ago

16 Posts

8 Users

7 Reactions

6,694 Views

RSS

Posts: 1

CodeX

Feb 12, 2023 2:38 am

(@codex)

New Member

Joined: 3 years ago

Hi @ddsouza1, just remove the _ from the last statement and you should be good go.

Reply

Page 2 / 2 Prev

Recent Posts

Advanced Interfaces: Functional Interfaces - Part 2 (Context & Capturing)

In Part 1, we explored the concept of functional interf...

By FisoThemes , 2 months ago
Advanced Interfaces: Functional Interfaces - Part 1

Lately, I’ve been thinking a lot about how to abstract ...

By FisoThemes , 2 months ago
RE: Twincat4026, Running Inside dockerized Windows11, Access via Mstsc

A lot has changed since the last post.I now run HyperV ...

By RomanG , 4 months ago
MMOexp Poe 2 offering a detailed look at skills

Path of Exile 2 (PoE 2) continues the legacy of its pre...

By BennieDe , 4 months ago
MMOexp Diablo4 on supporting abilities to soften up enemies

In Diablo 4, the Barbarian is a brutal powerhouse known...

By BennieDe , 4 months ago
MMOexp FC26 to climb the ranks

In EA FC 26, central midfielders (CMs) are often the he...

By BennieDe , 4 months ago
RE: Twincat4026, Running Inside dockerized Windows11, Access via Mstsc

@romang Hi, are you enable to enter in run mode in Twin...

By Gauth , 4 months ago
TwinCAT 3.1 (Build 4026) & Git – Online Change fails after cloning project (mapping mismatch)

Hi everyone, we’re currently running a TwinCAT 3.1 pr...

By funka84 , 4 months ago
RE: System time to DT

Hello, Did you try this ? DateTime:= FILETIME64_TO_...

By Alex , 5 months ago
System time to DT

Hi I have a very simple task that I am struggling wit...

By jthyge , 5 months ago

Share:

17 Forums
406 Topics
1,105 Posts
2 Online
1,185 Members

Forum Icons: Forum contains no unread posts Forum contains unread posts

Topic Icons: Not Replied Replied Active Hot Sticky Unapproved Solved Private Closed

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.

Necessary

Always Enabled

Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.

Cookie	Duration	Description
cookielawinfo-checkbox-analytics	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional	11 months	The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy	11 months	The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.

Functional

Performance

Analytics

Others