toString

[fabiancook]

🚀 Feature Proposal

Produce a string from any vnode

Motivation

To output a vnode as a string for client usage.

Example

const node = (
  <container>
    <text>Left</text>
    <text>Right</text>
  </container>
);

Consuming the result iteratively as it is generated:

for await (const iteration of toString(node)) {
  console.log({ iteration });
}

Resolving the complete string:

const value = await toString(node);

[fabiancook]

The initial implementation of toString is available here

x/packages/fringe/src/string.ts

Line 95 in 6db6e3c

export function toString(node: VNode): IterablePromise<string>

It it marked as experimental.

It includes support for "this" to be bound to, which allows for customisation of how the string is generated. An example of this is the quirks of HTML, including script requiring to contain a body

Usage of this can be seen here:

https://github.com/opennetwork/environment/blob/415ce57c430422278b5f316a74db76e8ff556526/src/example/fetch.ts#L18-L32

function isScalar(node: VNode) {
    if (!node.scalar) return false;
    const tags: unknown[] = ["script", "link", "meta"];
    return !tags.includes(node.source);
}

function getBody(node: VNode, body: string) {
    if (body) {
        return `\n${body.split("\n").map(value => `  ${value}`).join("\n")}\n`;
    }
    if (node.source !== "script") {
        return ""
    }
    return "\n";
}

https://github.com/opennetwork/environment/blob/415ce57c430422278b5f316a74db76e8ff556526/src/example/fetch.ts#L57

const string = await toString.call({ isScalar, getBody }, view);

[fabiancook]

By default deno's typescript doesn't like the usage of a .then function that isn't a "real promise", so this API may be unusable there. Potentially we can use a real promise, and assign our async iterator to it.