JavaScript blocks display of the other side of card

Anki Card Design
1

I’m designing a card type using JavaScript.
I want a card to show only a part of a field content.
For instance, if Eng field contains
spine<br>backbone
I want the front of the card to display
spine
(the part before new line).

Front template looks like this:

<script>
let list = "{{Eng}}".replace("<br>", "\n");
let word = list.match(/.*/);
document.write("Eng: ");
document.write(word);
document.write("<br>Rus?");
</script>

Back template looks like this:

{{Rus}}

When I review this card, the front side is displayed correctly:
Eng: spine
Rus?

But when I click Show answer, the back side, instead of showing {{Rus}}
позвоночник
shows the same what was displayed on the front side:
Eng: spine
Rus?

If I delete JavaScript from the front template and write only {{Eng}}, then both the front and back sides are displayed correctly. But if I add JavaScript on the front side, the other side of the card stops working.

I saw some ideas about using .innerHTML instead of document.write and also about adding {} around the code, but I don’t understand their application and therefore cannot test them.

Is the issue with my code or with Anki? How to fix it?
PS: I’m using latest version of Desktop Anki (2.1.49) on Windows 10.

2

Just as an aside, this has nothing to do with your topic, but for the ease of read of people you will answer you question: this forum uses Markdown.
This means that to write HTML code, you can enclose it in triple backquotes:

```html
<script>
let list = "{{Eng"".replace("<br>", "\n");
...
</script>
```

will render as

<script>
let list = "{{Eng}}".replace("<br>", "\n");
...
</script>
1 Like
3

Thank you, BlackBeans! I applied it and the post looks better now

4

The problem here is mainly document.write(), which clears the document on first write as far as I understand from Document.write() - Web APIs | MDN

Try this front template:

<div id="front"></div>

<script>
var list = "{{Eng}}".replace("<br>", "\n");
var word = list.match(/.*/);
var front = document.getElementById("front");
front.innerHTML = `Eng: ${word}<br>Rus?`;
</script>

You also have to use var instead of let or you will get errors because Anki uses the same webview for front and back templates and only recycles it periodically.

3 Likes