Writing to properties fails in browser

[fatadel]

Create foo.html with the following code:

<script src="https://cdn.jsdelivr.net/npm/@node-wot/browser-bundle@latest/dist/wot-bundle.min.js"></script>
<script>
    const servient = new Wot.Core.Servient();
    servient.addClientFactory(new Wot.Http.HttpClientFactory());
    const helpers = new Wot.Core.Helpers(servient);
    servient.start().then((thingFactory) => {
        helpers
            .fetch('http://plugfest.thingweb.io:8083/testthing')
            .then((td) => {
                thingFactory.consume(td).then((thing) => {
                    thing.writeProperty('bool', false);
                });
            })
            .catch((error) => {
                window.alert("Could not fetch TD.\n" + error);
            });
    });
</script>

Expected result:
No errors, successful write operation.

Actual result:
Error in console, write operation not performed.

[derwehr]

I get a similiar error trying to write to properties:

from-browser.js:2 Uncaught (in promise) Error: Readable.from is not available in the browser
    at module.exports (from-browser.js:2:9)
    at Readable.from (_stream_readable.js:1115:12)
    at ContentSerdes.valueToContent (content-serdes.js:112:61)
    at ConsumedThing.eval (consumed-thing.js:428:54)
    at Generator.next (<anonymous>)
    at eval (consumed-thing.js:28:71)
    at new Promise (<anonymous>)
    at __awaiter (consumed-thing.js:24:12)
    at ConsumedThing.writeProperty (consumed-thing.js:415:16)

A work-around, that involves editing /dist/ files I found is:
Changing /node_modules/@node-wot/core/dist/content-serdes.js line 92 from

if (value instanceof es2018_1.ReadableStream) {

to

if (value instanceof ReadableStream) {

With this editing /dist/ files, this is of course not viable, but might help in finding the problem.

[sebastiankb]

just for record: the webui app has the same problem when I call an action:

[relu91]

After plumbing into the inner workings of broserify and the Web platform, I've found that sadly stream upload is not supported for browsers. This means that we can't use a stream to write properties or invoke actions. Solving this issue is going to be tricky but I hope to find a patch that will only be active on browser environments.

For the ones that are curious. Here are the relevant issues:
whatwg/fetch#1438
https://bugs.chromium.org/p/chromium/issues/detail?id=688906

[relu91]

PR in flight; it should fix the issue but it is a workaround due to my previous comment. I would close this issue when it is properly merged and keep track of #785 (comment) in another issue.

[danielpeintner]

@relu91 I am not sure if the issue is really solved.
I tried the WebUI and I still run into issues

Error: Readable.from is not available in the browser

Note: It is different to the one @sebastiankb and others were seeing before...

To reproduce the problem

1. Build node-wot
2. Open <node-wot-folder>/examples/browser/index.html locally in a browser and consume http://plugfest.thingweb.io:8083/testthing
3. Invoke "int-int" action

[danielpeintner]

FYI: I updated the online version also.
see http://plugfest.thingweb.io/webui/