How do we import Blockly into an Angular 7 application?

user_899577 0
Viewed 3508

I'm trying to use Blockly in an Angular 7 application but I'm unable to inject the Blockly editor.

I have downloaded the files from https://developers.google.com/blockly/guides/get-started/web and copied blockly_compressed.js into my src directory (and renamed it blockly.js). I then try to access Blockly from my component and get errors.

What I have tried:

import "../blockly.js"

Does not compile, gives "error TS2304: Cannot find name 'Blockly'."

import { Blockly } from '../blockly'

Compiles, but gives the following error when the app is opened in a browser:

ERROR TypeError: _blockly__WEBPACK_IMPORTED_MODULE_4__.Blockly.inject is not a function

Adding a blockly.d.ts file with the following:

export namespace Blockly {
    export function inject(div: string, config: any): void;
}

Gives the same error as above.

Any suggestions on what else I could try?

blockly angular7 angular
5 Answers

I was able to setup with the config mentioned below -

install blockly with npm -

npm install git://github.com/google/blockly.git#1.20190419.0

included below files in scripts section of angular.json file -

    "scripts": [
      "node_modules/blockly/blockly_compressed.js",
      "node_modules/blockly/blocks_compressed.js",
      "node_modules/blockly/msg/js/en.js",
      "src/assets/blockly/custom_blocks.js"
    ]

added below lines in my component html file -

  <div id="blocklyDiv" style="width: 100%; height: 100%"></div>
  <xml id="toolbox" style="display: none">
    <category name="Control" colour="120">
      <block type="controls_if"></block>
      <block type="controls_repeat_ext" disabled="true"></block>
    </category>
    <category name="Text" colour="230">
      <block type="text"></block>
      <block type="text_print"></block>
    </category>
    <category name="Custom" colour="360">
      <block type="begin"></block>
      <block type="move"></block>
      <block type="end"></block>
    </category>
  </xml>

angular will throw error at this point saying it does not recognise the blockly tags. So need to use NO_ERRORS_SCHEMA in the module or can represent the toolbar XML as a string in the component TS file and use it to inject blockly.

my component TS file -

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute, Router } from '@angular/router';
import { ProgramService } from '../services/program.service';
import { IProgram } from '../models/program';

declare var Blockly: any;

@Component({
  selector: 'app-program-create',
  templateUrl: './program-create.component.html',
  styleUrls: ['./program-create.component.scss']
})
export class ProgramCreateComponent implements OnInit {
  title: string;
  programName: string;
  program: IProgram;
  workspace: any;

  constructor(
    private route: ActivatedRoute,
    private programService: ProgramService,
    private router: Router
  ) {
    this.title = 'Create Visual Program';
    this.route.params.subscribe(params => {
      this.programName = params['programName'];
      this.program = this.programService.getOne(this.programName);
      if (!this.program) {
        this.program = {
          name: this.programName,
          xmlData: null
        };
      }
      console.log(
        'creating/editing the program - ',
        JSON.stringify(this.program)
      );
    });
  }

  ngOnInit() {
    this.workspace = Blockly.inject('blocklyDiv', {
      toolbox: document.getElementById('toolbox'),
      scrollbars: false
    });

    if (this.program.xmlData) {
      this.workspace.clear();
      Blockly.Xml.domToWorkspace(
        Blockly.Xml.textToDom(this.program.xmlData),
        this.workspace
      );
    }
  }

  saveProgram(): void {
    this.program.xmlData = Blockly.Xml.domToText(
      Blockly.Xml.workspaceToDom(this.workspace)
    );
    console.log('saving the program - ', JSON.stringify(this.program));
    this.programService.upsertOne(this.program);
    this.router.navigate(['listProgram']);
  }
}

I have written an article explaining this in details here - Integrate Google Blockly with Angular

user_12988240

My answer does not put the XML into the template itself, but rather in a variable which enable the integration without the NO_ERRORS_SCHEMA import in the module.

Step 1: Download the files from Blockly website, and look for:

  • blockly_compressed.js
  • blocks_compressed.js

  • en.js (Or any language that you want your blockly to be in)

    Copy and paste them into src/assets/blockly.

Step 2: In your angular.json file, add the following ( in projects.architect.build.options ):

"scripts": [
          "src/assets/blockly/blockly_compressed.js",
          "src/assets/blockly/blocks_compressed.js",
          "src/assets/blockly/en.js"
]

Step 3: In your component.ts :

import { Component, AfterViewInit } from '@angular/core';
declare var Blockly: any

@Component({
  template: `<div id="blocklyDiv" style="height: 480px; width: 600px;"></div>`,
  selector: 'app-blockly',
  styleUrls: ['./blockly.component.scss']
})

export class BlocklyComponent implements AfterViewInit {
  ngAfterViewInit(): void {
    const toolbox = `
      <xml>
        <block type="controls_if"></block>
        <block type="controls_whileUntil"></block>
      </xml>`;
    Blockly.inject('blocklyDiv', { toolbox });
  }
}

And that's it !

user_15034490

I assume you're using @angular/cli.

Demo

Step 1: Install blockly

npm install blockly

Step 2: Add scripts to angular.json under the architect node:

"scripts": [
   "node_modules/blockly/blockly_compressed.js",
   "node_modules/blockly/blocks_compressed.js",
   "node_modules/blockly/msg/js/en.js"
]

Step 3: Add NO_ERRORS_SCHEMA to your AppModule (this is so that you can define custom tags in your components)

@NgModule({
  imports:      [ BrowserModule, AppRoutingModule ],
  declarations: [ AppComponent ],
  bootstrap:    [ AppComponent ],
  exports: [AppComponent],
  schemas: [NO_ERRORS_SCHEMA]
})
export class AppModule {
}

Step 4: Create a Component, declare Blockly as any, and implement AfterViewInit so that you can access the blockly-related elements in the DOM: 

import { Component, AfterViewInit, ViewChild, ElementRef } from '@angular/core';
declare var Blockly: any;

@Component({
  selector: 'app-root',
  template: `
    <div id="blocklyDiv" style="height: 480px; width: 600px;"></div>
    <xml id="toolbox" #toolbox style="display: none">
            <block type="controls_if"></block>
            <block type="logic_compare"></block>
            <block type="controls_repeat_ext"></block>
            <block type="math_number"></block>
            <block type="math_arithmetic"></block>
            <block type="text"></block>
            <block type="text_print"></block>
    </xml>
  `
})
export class AppComponent implements AfterViewInit {
  workspace: any;
  @ViewChild('toolbox') toolbox: ElementRef;

  ngAfterViewInit(): void {
    this.workspace = Blockly.inject('blocklyDiv',
    {toolbox: this.toolbox.nativeElement });
  }
}

NOTE: The Blockly package in NPM is at v1.0, while the latest version is v1.2. To use the latest, just download the library, put it in a known directory, and fix your script references (Step 2).

user_36616300
user_4130320

You should add it to angular.json firstly. So angular CLI can build it.

        "scripts": [
          "../blockly.js"
        ]
user_87625970
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