display of the blocks as SVG in instruction-component

src/components/Blockly/BlocklyComponent.css

@@ -1,7 +0,0 @@
-#blocklyDiv {
-  height: 100%;
-  min-height: 500px;
-  width: 100%;
-  /* border: 1px solid #4EAF47; */
-  position: relative;
-}

src/components/Blockly/BlocklyComponent.jsx

@@ -22,7 +22,6 @@
  */
 
 import React from 'react';
-import './BlocklyComponent.css';
 
 import Blockly from 'blockly/core';
 import locale from 'blockly/msg/en';

src/components/Blockly/BlocklySvg.js

@@ -0,0 +1,65 @@
+import React, { Component } from 'react';
+
+import * as Blockly from 'blockly/core';
+
+class BlocklySvg extends Component {
+
+  constructor(props) {
+    super(props);
+    this.state = {
+      svg: ''
+    };
+  }
+
+  componentDidMount() {
+    this.getSvg();
+  }
+
+  componentDidUpdate(props) {
+    if(props.initialXml !== this.props.initialXml){
+      this.getSvg();
+    }
+  }
+
+  getSvg = () => {
+    const workspace = Blockly.getMainWorkspace();
+    workspace.clear();
+    Blockly.Xml.domToWorkspace(Blockly.Xml.textToDom(this.props.initialXml), workspace);
+    var canvas = workspace.svgBlockCanvas_.cloneNode(true);
+
+    if (canvas.children[0] !== undefined) {
+      canvas.removeAttribute("transform");
+
+      // does not work in  react
+      // var cssContent = Blockly.Css.CONTENT.join('');
+      var cssContent = '';
+      for (var i = 0; i < document.getElementsByTagName('style').length; i++) {
+        if(/^blockly.*$/.test(document.getElementsByTagName('style')[i].id)){
+          cssContent += document.getElementsByTagName('style')[i].firstChild.data.replace(/\..* \./g, '.');
+        }
+      }
+
+      var css = '<defs><style type="text/css" xmlns="http://www.w3.org/1999/xhtml"><![CDATA[' + cssContent + ']]></style></defs>';
+
+      var bbox = document.getElementsByClassName("blocklyBlockCanvas")[0].getBBox();
+      var content = new XMLSerializer().serializeToString(canvas);
+
+      var xml = `<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"
+                  width="${bbox.width}" height="${bbox.height}" viewBox="${bbox.x} ${bbox.y} ${bbox.width} ${bbox.height}">
+                  ${css}">${content}</svg>`;
+
+      this.setState({svg: xml});
+    }
+  }
+
+  render() {
+    return (
+      <div
+        style={{display: 'flex', justifyContent: 'center', transform: 'scale(0.8) translate(0, calc(100% * -0.2 / 2))'}}
+        dangerouslySetInnerHTML={{ __html: this.state.svg }}
+      />
+    );
+  };
+}
+
+export default BlocklySvg;

src/components/Blockly/BlocklyWindow.js

@@ -3,7 +3,8 @@ import PropTypes from 'prop-types';
 import { connect } from 'react-redux';
 import { onChangeWorkspace, clearStats } from '../../actions/workspaceActions';
 import * as De from './msg/de';
-import BlocklyComponent from './';
+import BlocklyComponent from './BlocklyComponent';
+import BlocklySvg from './BlocklySvg';
 import * as Blockly from 'blockly/core';
 import './blocks/index';
 import './generator/index';
@@ -32,20 +33,22 @@ class BlocklyWindow extends Component {
 
   componentDidUpdate(props) {
     const workspace = Blockly.getMainWorkspace();
-    var initialXML = this.props.initialXml
-    if(props.initialXml !== initialXml){
+    var xml = this.props.initialXml
+    // if svg is true, then the update process is done in the BlocklySvg component
+    if(props.initialXml !== xml && !this.props.svg){
       // guarantees that the current xml-code (this.props.initialXml) is rendered
       workspace.clear();
-      if(!initialXML) initialXML = initialXml;
-      Blockly.Xml.domToWorkspace(Blockly.Xml.textToDom(initialXML), workspace) ;
+      if(!xml) xml = initialXml;
+      Blockly.Xml.domToWorkspace(Blockly.Xml.textToDom(xml), workspace);
     }
     Blockly.svgResize(workspace);
   }
 
   render() {
     return (
+      <div>
         <BlocklyComponent ref={this.simpleWorkspace}
-        style={this.props.blocklyCSS}
+          style={this.props.svg ? {height: 0} : this.props.blocklyCSS}
           readOnly={this.props.readOnly !== undefined ? this.props.readOnly : false}
           trashcan={this.props.trashcan !== undefined ? this.props.trashcan : true}
           renderer='zelos'
@@ -73,8 +76,9 @@ class BlocklyWindow extends Component {
           }}
           initialXml={this.props.initialXml ? this.props.initialXml : initialXml}
         >
-
         </BlocklyComponent >
+        {this.props.svg && this.props.initialXml ? <BlocklySvg initialXml={this.props.initialXml}/> : null}
+      </div>
     );
   };
 }

src/components/Home.js

@@ -87,7 +87,7 @@ class Home extends Component {
               </IconButton>
             </Tooltip>
             <TrashcanButtons />
-            <BlocklyWindow />
+            <BlocklyWindow blocklyCSS={{height: '500px'}}/>
           </Grid>
           {this.state.codeOn ?
             <Grid item xs={12} md={6}>

src/components/Tutorial/Assessment.js

@@ -39,7 +39,10 @@ class Assessment extends Component {
         <div style={{float: 'right', height: '40px'}}><WorkspaceFunc solutionCheck/></div>
         <Grid container spacing={2} style={{marginBottom: '5px'}}>
           <Grid item xs={12} md={6} lg={8}>
-            <BlocklyWindow initialXml={statusTask ? statusTask.xml ? statusTask.xml : null : null}/>
+            <BlocklyWindow
+              initialXml={statusTask ? statusTask.xml ? statusTask.xml : null : null}
+              blocklyCSS={{height: '500px'}}
+            />
           </Grid>
           <Grid item xs={12} md={6} lg={4} style={isWidthDown('sm', this.props.width) ? {height: 'max-content'} : {}}>
             <Card style={{height: 'calc(50% - 30px)', padding: '10px', marginBottom: '10px'}}>

src/components/Tutorial/Builder/BlocklyExample.js

@@ -114,7 +114,10 @@ class BlocklyExample extends Component {
             <div style={{marginTop: '10px'}}>
               <Grid container className={!this.props.value || this.props.error ? this.props.classes.errorBorder : null}>
                 <Grid item xs={12}>
-                  <BlocklyWindow initialXml={initialXml}/>
+                  <BlocklyWindow
+                    initialXml={initialXml}
+                    blocklyCSS={{height: '500px'}}
+                  />
                 </Grid>
               </Grid>
               <Button

src/components/Tutorial/Instruction.js

@@ -27,12 +27,7 @@ class Instruction extends Component {
         <Grid container spacing={2} style={{marginBottom: '5px'}}>
           <Grid item xs={12}>
             <BlocklyWindow
-              trashcan={false}
-              readOnly={true}
-              zoomControls={false}
-              grid={false}
-              move={false}
-              blocklyCSS={{minHeight: '300px'}}
+              svg
               initialXml={step.xml}
             />
           </Grid>