WorkflowEngine Designer for Angular Sample

Introduction

WorkflowEngine Designer for Angular is a library developed to facilitate the use of this component. It provides a convenient way to interact and create the Workflow Designer on your web page using Angular. This section explains you how to add the Workflow Designer to your web application in a convenient format - Get Started - that thoroughly interprets the procedure, step by step.

Prerequisites

To run the example below, you should create the WorkflowEngine backend capable of handling requests from the Workflow Designer, the NodeJS runtime, and the NPM package manager to download the required packages. That is all you need for further action.

Get Started

First, you should install a command line utility to work comfortably with your Angular application. For this, run the following command:

npm install -g @angular/cli

After executing this command, the Angular command line interface will be globally installed on your computer, and you can proceed to creating our project. For this, also run the following code:

ng new workflow-designer-angular-sample

After execution, these two questions will be asked:

• Use Angular Routing - No;
• Preferred style sheet language (CSS, SCSS, etc.) - CSS.

After confirmation, the Angular project will be created in the workflow-designer-angular-sample folder. The workflow-designer-angular package must be installed. To start, do the following:

cd workflow-designer-angular-sample
npm install @optimajet/workflow-designer-angular
npm start

Now, the workflow-designer-angular-sample folder contains all the necessary files for our web application. Their file hierarchy is presented below (depending on the version used, it may differ):

├── node_modules
│   └── ...
├── src
│   ├── app
│   │   ├── app.component.css
│   │   ├── app.component.html
│   │   ├── app.component.spec.ts
│   │   ├── app.component.ts
│   │   └── app.module.ts
│   ├── assets
│   │   └── .gitkeep
│   ├── environments
│   │   ├── environment.prod.ts
│   │   └── environment.ts
│   ├── favicon.ico
│   ├── index.html
│   ├── main.ts
│   ├── poyfills.ts
│   ├── styles.css
│   └── test.ts
├── angular.json
├── karma.conf.js
├── package.json
├── package-lock.json
├── README.md
├── tsconfig.app.json
├── tsconfig.json
└── tsconfig.spec.json

Now let's go directly to connecting and displaying the Workflow Designer in this web application. First, we should add the WorkflowDesigner styles. For this, add the following import in the style.css file:

@import '~@optimajet/workflow-designer/dist/workflowdesigner.min.css'

Next, we need to set up the Angular component. To do this, open the file src/app/app.component.ts and paste the following content:

import { Component } from '@angular/core';
import { WorkflowDesignerComponent } from '@optimajet/workflow-designer-angular';

@Component({
  selector: 'app-root'
})
export class AppComponent {
  schemeCode = '<YOUR_SCHEME_CODE_VALUE>';
  processId = '';
  designerConfig = {
    apiurl: '<YOUR_API_URL_VALUE>',
    widthDiff: 0,
    heightDiff: 0
  };
}

This code imports the WorkflowDesigner component for use in the markup code, and also sets the necessary parameters for passing them to the WorkflowDesigner component, namely:

• schemeCode - is the code for the Workflow diagram to be displayed in the Workflow Designer.
• processId - is the identifier of the WorkflowEngine process.
• designerConfig - are the direct settings for the Designer indicating all the necessary parameters, namely: the HTTP address of the WorkflowAPI for interacting with the server side of the application (apiurl), the difference between the total page width and the width available for the WorkflowDesigner (widthDiff), and the difference between the total page height and the height available for the WorkflowDesigner (heightDiff) to display the WorkflowDesigner window. For a more detailed list of the parameters, see the Designer section of the documentation page about the WorkflowEngine.

NOTE: Be careful with the case of the characters when specifying the parameters. For example: apiUrl and apiurl are two completely different values.

If you want to display the Workflow scheme in the Workflow Designer interface, set the required value to the schemecode variable, and assign the empty string to the processId. In case you want to display the Workflow process, assign the empty string to the schemecode, and the required value to the processId variable of the WorkflowEngine process identifier.

Then, paste the following code into the src/app/app.component.html file:

<workflow-designer 
  [schemeCode]="schemeCode"
  [processId]="processId"
  [designerConfig]="designerConfig"
></workflow-designer>

Here the WorkflowDesigner is drawn and its parameters, specified in the src/app/app.component.ts file, are initialized.

And finally, all that remains is to edit the src/app/app.module.ts file as follows:

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { WorkflowDesignerModule } from '@optimajet/workflow-designer-angular';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    WorkflowDesignerModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Here you just need to add the WorkflowDesignerModule initialization, and join it to the parameters of the application module.

Now, run the npm start command and your page will display something like that (the Workflow diagram may differ):

How to Call WorkflowDesigner Functions inside Angular Component

The @optimajet/workflow-designer-angular component is a wrapper over the usual WorkflowDesigner. Some of the most commonly used methods are wrapped in the @optimajet/workflow-designer-angular component for convenience. To use them, do the following:

1. Import the ViewChild from @angular/core into your component, create a class variable using the @ViewChild decorator (e.g.this.workflowDesigner) of the WorkflowDesignerComponent type, and set the value undefined to it; in the WorkflowDesigner component, assign the value of the variable you created to the ref parameter:

   import { Component, ViewChild } from '@angular/core';
   import { WorkflowDesignerComponent } from '@optimajet/workflow-designer-angular';
   
   @Component({
     selector: 'app-root',
     templateUrl: './app.component.html',
     styleUrls: ['./app.component.css']
   })
   export class AppComponent {
     workflowDesignerParameters = {
       schemeCode: '<YOUR_SCHEME_CODE_VALUE>',
       processId: '',
       designerConfig: {
         name: 'wfdesigner',
         apiurl: '<YOUR_API_URL_VALUE>',
         templatefolder: '/templates/',
         widthDiff: 0,
         heightDiff: 0
       }
     };
   
     @ViewChild(WorkflowDesignerComponent) workflowDesigner?: WorkflowDesignerComponent = undefined;
   
     yourWorkflowFunction() {
       // Your code here...
     }
   }

2. Now you can use the methods of the WorkflowDesigner component directly in your component:

   yourWorkflowFunction() {
       this.workflowDesigner.methodName();
   }

A complete list of the methods available for use from the WorkflowDesigner component is given below:

Method Name	Description
clearScheme()	Clears the designer, equivalent of creating empty scheme design
getDesignerErrors()	Get Workflow Designer Errors Returns Errors in Workflow Designer
save(successCallback, errorCallback)	Save Workflow scheme successCallback Function which will be executed if save was successful errorCallback Function which will be executed if save operation failed
downloadScheme()	Download XML file with Workflow Scheme description
downloadBpmn()	Download BPMN file with BPM description of the scheme.
upload(uploadType, callback)	Upload BPMN or XML file. uploadType Upload type, can be 'scheme' or 'bpmn' callback Function that will be executed after uploading file
isSchemeExist()	Check for scheme existence by the scheme code from props. Returns {boolean} If scheme exists true, otherwise, false
isProcessExist()	Check for process existence by scheme code and process id given in props. Returns {boolean} If process exists true, otherwise, false
refresh()	Refresh data in WorkflowDesigner

In case you want some methods that are not presented in this table, use the WorkflowDesigner and call its methods directly without wrappers, for example:

this.workflowDesigner.innerDesigner.methodName();