Error when trying to generate javascript from xml that contains overridden shadows

[Alexejhero]

I'm having an issue saving variables with node-blockly. Here is my code:

First attempt (code)

```js const Blockly = require('node-blockly'); var xml = decodeURIComponent(data.req.body.xml); var dom = Blockly.Xml.textToDom(xml); var workspace = new Blockly.Workspace(); Blockly.Xml.domToWorkspace(dom, workspace); var js = Blockly.JavaScript.workspaceToCode(workspace); ```

If there are no overridden shadows, the code is generated successfully. But if there are, I get the following error:

First attempt (error)

``` ReferenceError: Element is not defined at Object.module.exports.Blockly.Xml.domToVariables (node_modules\node-blockly\lib\blockly_compressed.js:997:93) at Object.module.exports.Blockly.Xml.domToWorkspace (node_modules\node-blockly\lib\blockly_compressed.js:991:441) at module.exports (src\requests\save.js:45:17) ```

Upon doing some research, I figured out that Element is a DOM interface which is not available in Node.JS, so I installed jsdom and jsdom-global and changed my code to this:

Second attempt (code)

```js const Blockly = require('node-blockly'); require('jsdom-global')(); var xml = decodeURIComponent(data.req.body.xml); var dom = Blockly.Xml.textToDom(xml); var workspace = new Blockly.Workspace(); Blockly.Xml.domToWorkspace(dom, workspace); var js = Blockly.JavaScript.workspaceToCode(workspace); ```

This resulted in the following error:

Second attempt (error)

``` Error: Trying to set block style to list_blocks before theme was defined via Blockly.setTheme(). at module.exports.Blockly.Block.setStyle (node_modules\node-blockly\lib\blockly_compressed.js:1465:83) at module.exports.Blockly.Block.init (node_modules\node-blockly\lib\blocks_compressed.js:26:511) at new module.exports.Blockly.Block (node_modules\node-blockly\lib\blockly_compressed.js:1445:428) ```

So then I decided to set the style first, changing my code to this:

Third attempt (code)

```js const Blockly = require('node-blockly'); require('jsdom-global')(); Blockly.setTheme(Blockly.Themes.Classic); var xml = decodeURIComponent(data.req.body.xml); var dom = Blockly.Xml.textToDom(xml); var workspace = new Blockly.Workspace(); Blockly.Xml.domToWorkspace(dom, workspace); var js = Blockly.JavaScript.workspaceToCode(workspace); ```

Which then resulted in this error:

Third attempt (error)

``` TypeError: Failed to execute 'appendChild' on 'Node': parameter 1 is not of type 'Node'. at Object.convert (node_modules\node-blockly\node_modules\jsdom\lib\jsdom\living\generated\Node.js:749:11) at HTMLUnknownElement.appendChild (node_modules\node-blockly\node_modules\jsdom\lib\jsdom\living\generated\Node.js:280:29) at Object.module.exports.Blockly.Xml.blockToDom (node_modules\node-blockly\lib\blockly_compressed.js:12517:54) ```

The error originates from this statement:

Error details


After dome debugging, I saw that the type of the parameter was HTMLUnknownElement.

I've been trying to fix this for a while but have made no progress, so I decided to open this issue.

---

Running an Express app on Node.JS version 8.15.1

File can be found here: https://github.com/AlexejheroYTB/Dlockly/blob/master/src/requests/save.js

[mo4islona]

First of all, library is already use jsdom in NodeJS env to avoid errors with missing DOM interfaces. Could you give an example of xml that throws error?

[Alexejhero]

I see that JSDOM is required, but still, the Element interface is not defined on the global object.

Anyway, I will provide an example xml shortly.

[Alexejhero]

Actually, I just realized that it may be from one of my custom blocks. I can use variables with default blocks just fine.

[Alexejhero]

Actually, I think I know what this is about. It's about blocks that have OVERRIDDEN SHADOWS

---

This works just fine:

Code

```xml EQ ADD 1 1 2 ```

---

But this does not:

Code

```xml EQ ADD 1 1 1 1 2 ```

[Alexejhero]

To clarify, by "overridden shadows", I mean blocks which have default values (shadows) that have been overridden with other blocks.

[mo4islona]

Please try latest 1.0.38 version

[Alexejhero]

Unfortunately I am unable to test it right now, but I will do so as soon as I can.

[Alexejhero]

Should I try 1.0.38 or 1.0.40?

[Alexejhero]

Tried 1.0.40, still the same error:

TypeError: Failed to execute 'appendChild' on 'Node': parameter 1 is not of type 'Node'.
    at Object.convert (node_modules\jsdom\lib\jsdom\living\generated\Node.js:573:11)
    at HTMLUnknownElement.appendChild (node_modules\jsdom\lib\jsdom\living\generated\Node.js:273:31)
    at Object.module.exports.Blockly.Xml.blockToDom (node_modules\node-blockly\lib\blockly_compressed.js:987:24)
    at Object.module.exports.Blockly.Xml.blockToDom (node_modules\node-blockly\lib\blockly_compressed.js:987:95)
    at Object.module.exports.Blockly.Xml.blockToDom (node_modules\node-blockly\lib\blockly_compressed.js:987:95)
    at new module.exports.Blockly.Events.Create (node_modules\node-blockly\lib\blockly_compressed.js:967:172)
    at Object.module.exports.Blockly.Xml.domToBlock (node_modules\node-blockly\lib\blockly_compressed.js:998:243)
    at Object.module.exports.Blockly.Xml.domToWorkspace (node_modules\node-blockly\lib\blockly_compressed.js:993:13)
    at module.exports (src\requests\save.js:49:17)

[Alexejhero]

If I manually remove the shadow by changing the saved XML, it saves correctly even if I override it.

[Alexejhero]

Do you have any idea on what could be causing this issue? Could it be blocky itself, or just something with the node version?

[Alexejhero]

Or, are there any workarounds?

[Alexejhero]

I managed to find a workaround for this by manually removing shadow elements if there is a block element present at the same level.

Code

```js function removeOverwrittenShadowsRecursively(obj) { var shadowElement, blockElement; if (obj.elements) { for (var element of obj.elements) { if (element.name == "shadow") shadowElement = element; if (element.name == "block") blockElement = element; } } if (shadowElement && blockElement) removeFromArray(obj.elements, shadowElement); if (obj.elements) { for (var index in obj.elements) { obj.elements[index] = removeOverwrittenShadowsRecursively(obj.elements[index]); } } return obj; } function removeFromArray(arr) { var what, a = arguments, L = a.length, ax; while (L > 1 && arr.length) { what = a[--L]; while ((ax = arr.indexOf(what)) !== -1) { arr.splice(ax, 1); } } return arr; } ```

Nevertheless, this is still an issue that needs to be resolved with node-blockly.

[mo4islona]

I`ve added a test with your xml

https://github.com/mo4islona/node-blockly/blob/master/test/js_test.js#L132

Test are passed. No error. It produce 'if (1 + 1 == 2) {\n}\n' in JS.

[Alexejhero]

I have no idea why this is happening. I will try this with the latest version.

[Alexejhero]

I tried this again with the latest version, but I'm still having the same type error.

[Alexejhero]

Closing this due to inactivity. I haven't had this issue in a long time, although I've been using my script.

[curlyz]

@AlexejheroYTB I got the same problem, can you share how to use your script ? Where can I inject that ?

[Alexejhero]

Damn, it's been a while since I've touched this project. I'll look over it once I get home.