Node reordering issues

[yuretz]

First of all I would like to thank you for your awesome work. This micro-framework/library looks really interesting and very promising indeed.

I was playing with the example provided here and stumbled upon a couple of issues.

The first one is that sometimes, when re-rendering a re-ordered array, the first item is not displayed. I've tried both with data-id attribute in the template and without it, it doesn't help much. What am I doing wrong here?

The second one is just a DOMException being thrown when trying to render the reordered array.

Both issues are illustrated by this fiddle

[yuretz]

Just a small update. Everything renders as expected if the original array is cloned on each update. See this fiddle. However the original example in the documentation suggests that in-place array mutations should be possible too, so I still think this is an issue.

[joshgillies]

hey @yuretz nice bug report. It looks like this bug may have been introduced with #100. Testing your original example against hyperhtml@1.6.7 the list is rendered as expected -
https://jsfiddle.net/L3se6mw4/3/.

[WebReflection]

nice bug indeed ... but majinbuu is just fine. There is something weird going on here, the logic is perfectly fine but it misses one call. I will investigate more tomorrow but so far this works, which is reassuring:

const todo = [
  {id: 0, text: 'write documentation'},
  {id: 1, text: 'publish online'}
];
const list = [];
const aura = majinbuu.aura({splice() {
  console.log(arguments);
  return list.splice.apply(list, arguments);
}}, list);

majinbuu(aura, todo);

todo.push({id: 2, text: 'create Code Pen'});
majinbuu(aura, todo);

const strcmp = (a, b) => (a > b ? 1 : (a < b ? -1 : 0));
todo.sort((a, b) => strcmp(a.text, b.text));
majinbuu(aura, todo);

For some reason, the sort splice is invoked once instead of twice ... and not sure why is that.

[WebReflection]

P.S. and FYI: the reason cloning each object works is that you are creating new wires each time (always different nodes)

[joshgillies]

Oh and also:

I've tried both with data-id attribute in the template and without it, it doesn't help much.

for the record data-id holds no special meaning in hyperHTML - @WebReflection I wonder if that example should be changed? My worry is that by having <li data-id=${item.id}>...</li> we're confusing existing users of React that there's special meaning there, similar to how you would assign a key to nodes in React which is a hint for optimising the rendering of lists.

[WebReflection]

that's just an attribute, but here I have bigger problems to deal with ... 🤷‍♂️

[WebReflection]

@yuretz can you please test this version and tell me if everything looks good to you? Thanks
https://cdn.rawgit.com/WebReflection/hyperHTML/2495c8d46f5ccf63906c729d3f64c8e6abcba7c5/index.js

edit this is the fiddle with this version https://jsfiddle.net/58cnrsq4/

[WebReflection]

@joshgillies I don't know React much so I don't know what's wrong there. Does react deal in a special way with data-id ? Currently, React is way inferior to hyperHTML and others when it comes to attributes so I'm not sure I should penalize the documentation in favor of React weird cases. hyperHTML just set attributes, only data or events have special meanings but if you think something might really put people off please do file a PR to the documentation site, thank you!

[joshgillies]

@WebReflection confirmed with @yuretz original example that the latest as of 2495c8d resolves the issue.

Also regarding data-id I guess I was speculating a little, @yuretz if you can confirm whether you thought there was special meaning behind it that would help clear things up. 👍

[WebReflection]

I've also added the sorting test case and it's covered now. Since the fix is super ugly but kinda obvious, I'm going to push this as patch regardless (or I cannot sleep tonight)

[joshgillies]

@WebReflection adding a test case would be 👌 Nice work!

[WebReflection]

v1.8.1 patches this issue. Thanks everyone for tests and checks.

[yuretz]

Wow! That was fast super fast. Thank you for the fix and explanations!

@joshgillies I confirm, that I was indeed confused by data-id attributes and thought they were used in a special way to optimize DOM diffing.

[WebReflection]

thought they were used in a special way to optimize DOM diffing.

There is no virtual DOM in hyperHTML and the diffing is powered by Levenshtein distance through Majin Buu splice-based engine, which is there to perform the least amount of DOM operations to change from list-1 to list-2 in place.

Attributes in hyperHTML address actual DOM attributes, and nothing else. These are never special, unless these are events, a data attribute to pass directly some info if needed, or attributes natively present in the element prototype such <input value=${content}>.

In hyperHTML the DOM is always optimized, which is also why you don't need, as developer, to hint optimizations, hyperHTML does that for you out of the box.

One question though: is data-id a specific react thing? I might just change the name of that attribute if it has special meanings elsewhere and if it confuses newcomers.

Thanks.

[asapach]

There's a special attribute called key, which is kind of analogous to wire(obj). data-id is in no way special. I think what confused @yuretz was that you're using it in your example: https://viperhtml.js.org/hyperhtml/documentation/#api-1-0

[WebReflection]

I am using ... what? I'm just setting a data-id attribute there, not a key attribute

[sourcegr]

I am using ... what? I'm just setting a data-id attribute there, not a key attribute

@asapach said that the use of data-id confused @yuretz, and the data-id is in no way special, even in React.

This is exactly the case. Yuretz was confused and thought that the data-id has some kind of special meaning.

That said, I believe that @joshgillies was also confused about the data-id use on React :) Nothing special about it, as expected. All data-* attributes cannot be used by a framework as special in any way

[WebReflection]

everyone is confused, including me 😄

I feel like I cannot use attributes in hyperHTML examples or someone will be confused ... React page explicitly describes key as special, not sure why data-id would be consider special in that example, it's just a custom attribute.

Should I name it data-whatever and call it a day?

[asapach]

I'd just remove it to avoid confusion.

[WebReflection]

done

[yuretz]

Thank you guys and sorry for confusion I managed to create 😳
I've been probably disoriented by the fact that the framework we are currently using (riot.js) is using data-is attributes in a special way (as a marker for component mounting point) and this caused some weird interference in my mind regarding a possible special use of data-* attributes in hyperHTML, and that was a mistake indeed.
Now, due to @WebReflection and other guys explanations I think I've got a better understanding of how things actually work. 😌 I'll now go play more with it and try not to break it again 😉

[joshgillies]

LOL This thread it 💯 !

To be clear @papas-source I never said data-id holds special meaning in React 😛 just that's it's (obviously) easy for people coming from other frameworks to expect some type of special attributes React/Preact/Inferno has key and others, Riot with it's special data-* attributes, I could go on but - the final comment and clarification for new comers is (as mentioned by @WebReflection) - hyperHTML holds no special meaning to DOM attributes other than events, and data attribute to pass directly... data!

[sourcegr]

ohh Riot!

I wish there was a library that its syntax was close to Riot's syntax (which is - in my opinion - by far the best component-like friendly syntax) and its internals based on HyperHTML to be fast!

[WebReflection]

AFAIK that's already happening ... they were thinking of using hyperHTML