WorkflowDiagram.Nodes.Base 1.0.15

Workflow Diagram -- Low Code Platform

Workflow Diagram is used to create nodes with operations and connections between them, and then use runner which visits these nodes and execute operations, associated to them. Workflow diagram comes with Visual Designer written for Windows Forms.

Simple example:

WfDocument doc = new WfDocument(); 
WfRunner runner = new WfRunner(doc);
bool result = runner.RunOnce(doc);

In this example we create empty workflow document and execute it. This example does nothing, as well as most of managers. More complicated example:

WfDocument doc = new WfDocument();
WfConstantValueNode const1 = new WfConstantValueNode(1.0);
doc.Add(const1);
WfConstantValueNode const2 = new WfConstantValueNode(2.0);
doc.Add(const2);
WfConditionNode cond1 = new WfConditionNode(WfConditionalOperation.Equal);
doc.Add(cond1);

const1.Outputs[0].ConnectTo(cond1, "In1");
const2.Outputs[0].ConnectTo(cond1, "In2");

WfStorageValueNode stTrue = new WfStorageValueNode("Condition True");
doc.Add(stTrue);
WfStorageValueNode stFalse = new WfStorageValueNode("Condition False");
doc.Add(stFalse);

cond1.Connect("False", stFalse, "Run");
cond1.Connect("True", stTrue, "Run");

WfRunner runner = new WfRunner(doc);
bool result = runner.RunOnce(doc);

In this example we create two nodes, containing double constant value 1 and 2. Then we connect outputs of these nodes to node which has two inputs and makes logical operation on values receiving through its inputs. Then each output of this node connects to node, which saves result of the operation to the global storage. Here is the visualization of this workflow:

Of course, this is very simple example that has a less logic, but you've got the idea.

You can easily create your own nodes, define inputs which can accept this node, and outputs that this node can produce. The base class from your can create your own descendants is the WfNode class. However, if you wish your node support Visual Designer for Windows Forms, please use the WfVisualNodeBase class.

Related classes

WfNode

WfDocument

WfRunner

Common Nodes

There is already exists a set of nodes WorkflowDiagram.Nodes.Base, which you can use to make common arithmetic and logical operations and write your custom script to operate on input values. You can consider this set of nodes as source for visual programming. Though this set will be constantly expanded, you already can use the following nodes:

WfAbortNode -- immediately stops the execution and returns true or false value.

WfChangeNode -- check if input value was changed and pass execution to one of the outputs: 'yes' or 'no'.

WfCollectionNode -- use it's input item to execute one of the following operations: add (add item to collection if collection did not hold this item), remove (remove value to collection if collection holds item), reset (reset collection).

WfConditionNode -- performs one of the logical operations: and, or, equal, not equal, less, less or equal, greater, greater or equal on its two input values. Then depend on result, pass execution to one of its branch output 'true' or false

WfConstantValueNode -- defines constant value of one of following types: decimal, string or boolean.

WfForEachNode -- receives collection as input value and pass each item in this collection to its subtree, connected to its ForEach output. Think of it as foreach statement in c#.

WfIndexerNode -- get item from collection by index, defined in this node and pass it to next nodes. Supports: first, last and item by index.

WfRepeatNode -- repeat subtree execution by N times defined in this node. Think of it as for statement in c#.

WfScriptNode -- receives up to 6 input values and pass them through c# script. Used as base for arithmetic operations.

WfStorageValueNode -- allows you to store value in global storage and get value from it.

WfSwitchNode -- analog of switch statement in c#. Allows you to define a set of values and connect subtree to them. Input value will compare to the each of defined values and if it equals to the specific value the execution will pass to the brunch connected to this value.

Each of these nodes can be created and designed in Workflow Diagram's Visual Designer.

Visual Designer

Visual Designer is the descendant of the UserControl class, which you can use in your project, which allows your end-users to create and execute workflow diagram.

Heare are the examples

You created your own set of nodes, which allows to make algorithmic trading on crypto exchanges. Or you created advanced arithmetic operation nodes, which operates on time series and visualizer the operation results. Or your app allows to create application scheme and generates application based on this scheme. Or you want to create application which allows to create procedure generated landscapes.

The visual editor adds to your project a flexible customization and design.

Here is my example. I created CryptoTradingFramework application which supports Strategies. I created a set of nodes which allows my user creates their own strategy, test them on historical data and, using only visual design (ok, I not finished it yet ).

Visual Designer is the multi-document application. It supports standard file operations such as create new, open, save, save as. Also, it supports the Initialize, Run, Run Once commands for document. It is very well optimized, supports High DPI monitors and multi-monitors.

How To Create Nodes

On the left side there is Toolbox window, that contains a set of available nodes, that user can create. To create the desired node, drag and drop this node on the Diagram area (Diagram window).

How To Connect One Node To Other

If one wish to connect nodes, he should select connection mode be clicking Connect Nodes command from the upper diagram toolbar or to press Alt+C shortcut.

How To Set Nodes Parameters

To specify node’s parameters, please select the desired node. After that it’s parameters will be displayed in the Properties window. Use editors in this window to change node’s parameters.

How To Execute Workflow

After creating and configuring nodes, one can execute workflow. To do this, one should click RunOnce or Run command.