"Exploring the world of Typescript with the Drawflow library

Question

"Exploring the world of Typescript with the Drawflow library

Currently, I am integrating the fantastic Drawflow library created by @Jerosoler (available at: https://github.com/jerosoler/Drawflow) into my PrimeNg project.

User @BobBDE has provided typescript definitions for this library here: https://www.npmjs.com/package/@types/drawflow

My project utilizes PrimeNg with Angular 11 and Typescript 4.

I have successfully installed both the library and the definitions using npm commands. Everything seems to be in order as I can locate the JS library, and the definitions to use within Typescript.

Nevertheless, I am encountering an undefined error and I am having difficulty identifying what could possibly be incorrect...

In my component's HTML, I have included the following:

<div #drawflowDiv></div>

To access the div in my component's Typescript:

@ViewChild('drawflowDiv', {static: true}) 
drawflowDiv: HTMLElement;

Subsequently, in my ngOnInit function, I have the following setup:

ngOnInit(): void {
    console.log(this.drawflowDiv);
    const editor = new drawflow(this.drawflowDiv);
    editor.reroute = true;
    editor.editor_mode = 'edit';
    editor.drawflow = {.....}; // Default example JSON for the library
    editor.start();
}

There are no errors evident in the code, and the drawflow library is correctly connected. The console.log provides all the details of the HTML element within the div, indicating that it is not undefined. A screenshot of the console log is attached to this post.

Your assistance would be greatly appreciated, and I hope that someone here might have a solution.

Thanks in advance!

View screenshot of console output here

angular typescript npm undefined primeng

Answer 1

Answer №1

For a more reusable approach, consider encapsulating the code within a directive:

Directive file: app-draw-flow.directive.ts

import { Directive, ElementRef, OnInit } from '@angular/core';
import Drawflow from 'drawflow';

@Directive({
  selector: '[appDrawFlow]'
})
export class DrawFlowDirective implements OnInit {

  editor: Drawflow;

  constructor(private hostElementRef: ElementRef) { }

  ngOnInit() {
    if (!!this.hostElementRef?.nativeElement) {
      const { nativeElement } = this.hostElementRef;
      this.initializeDrawFlow(nativeElement);
    }
  }

  private initializeDrawFlow(element: HTMLElement): void {
    try {
      if (!!element) {
        this.editor = new Drawflow(element);
        this.editor.reroute = true;
        this.editor.editor_mode = 'edit';
        // this.editor.drawflow = {}
        this.editor.start();
      } else {
        console.error('Drawflow host element does not exist');
      }

    } catch (error) {
      console.error('Unable to start Drawflow', error);
    }
  }
}

Don't forget to include DrawFlowDirective as a declaration in the parent feature module where you plan to use it.

Here's an example of how to use it in your template:

<div appDrawFlow></div>

If you encounter any issues running it, verify your module declarations. Here is an example (partial snippet of app module):

@NgModule(
  {declarations: [DrawFlowDirective]}
)
export class AppModule { }

Answer 2

For a more reusable approach, consider encapsulating the code within a directive:

Directive file: app-draw-flow.directive.ts

import { Directive, ElementRef, OnInit } from '@angular/core';
import Drawflow from 'drawflow';

@Directive({
  selector: '[appDrawFlow]'
})
export class DrawFlowDirective implements OnInit {

  editor: Drawflow;

  constructor(private hostElementRef: ElementRef) { }

  ngOnInit() {
    if (!!this.hostElementRef?.nativeElement) {
      const { nativeElement } = this.hostElementRef;
      this.initializeDrawFlow(nativeElement);
    }
  }

  private initializeDrawFlow(element: HTMLElement): void {
    try {
      if (!!element) {
        this.editor = new Drawflow(element);
        this.editor.reroute = true;
        this.editor.editor_mode = 'edit';
        // this.editor.drawflow = {}
        this.editor.start();
      } else {
        console.error('Drawflow host element does not exist');
      }

    } catch (error) {
      console.error('Unable to start Drawflow', error);
    }
  }
}

Don't forget to include DrawFlowDirective as a declaration in the parent feature module where you plan to use it.

Here's an example of how to use it in your template:

<div appDrawFlow></div>

If you encounter any issues running it, verify your module declarations. Here is an example (partial snippet of app module):

@NgModule(
  {declarations: [DrawFlowDirective]}
)
export class AppModule { }

Answer 3

Answer №2

To include a drawing flow in your HTML component, simply add the following code:

<div id="drawflowContainer"></div>

Then, in the ngOnInit function:

this.drawFlowChart = new Drawflow(document.getElementById('drawflowContainer'));
this.drawFlowChart.initialize();
...

Answer 4

To include a drawing flow in your HTML component, simply add the following code:

<div id="drawflowContainer"></div>

Then, in the ngOnInit function:

this.drawFlowChart = new Drawflow(document.getElementById('drawflowContainer'));
this.drawFlowChart.initialize();
...

Answer 5

Answer №3

To properly initialize your editor, make sure to include the nativeElement in its creation:

Ensure that when you instantiate the drawflow editor, you pass in this.drawflowDiv.nativeElement like this:
const editor = new drawflow(this.drawflowDiv.nativeElement);

Answer 6

To properly initialize your editor, make sure to include the nativeElement in its creation:

Ensure that when you instantiate the drawflow editor, you pass in this.drawflowDiv.nativeElement like this:
const editor = new drawflow(this.drawflowDiv.nativeElement);

"Exploring the world of Typescript with the Drawflow library

Answer №1

Answer №2

Answer №3

Similar questions

What potential outcomes arise from independently initiating multiple components simultaneously?

Could it be possible for a Firestore onUpdate trigger's change parameter, specifically change.after.data() and change.before.data(), to become null or undefined?

Executing npm prepublish on a complete project

React Hot Toast useState is unfortunately not exported from the React library

Creating a seamless integration between Angular 2's auth guard and observables to enhance application security

Angular displays the error message TS2339, stating that the property 'handleError' is not found on the 'HeroService' type

Conflict arises due to an override of react-error-overlay@^6.0.9 conflicting with a direct dependency

"Converting to Typescript resulted in the absence of a default export in the module

Passing properties from the parent component to the child component in Vue3JS using TypeScript

I am having trouble resolving 'otp-input-react' in my project directory at D:projectappsrc

Switching from JavaScript to TypeScript resulted in React context not being located in its respective file

Refining Generic Types in TypeScript

When attempting to run npm install for @types/jquery, an error is returned stating "Invalid name: @types/jquery"

Ensuring TypeScript's strict null check on a field within an object that is part of an

React JS integrated with Stripe

Error message in Docker: "Command /bin/sh: 1: ng: not found; please make sure Angular

the Sprite fails to appear on the screen

CreateAsyncModule using an import statement from a variable

The KeyValuePair<string, Date> type in Typescript cannot be assigned to the KeyValuePair<number, string> type

What methods does the TypeScript compiler use to locate npm packages containing types?