feat(useEventSource): add transformer #4953

imddc · 2025-08-10T12:23:53Z

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⚠️ Slowing down new functions

Warning: Slowing down new functions

As the VueUse audience continues to grow, we have been inundated with an overwhelming number of feature requests and pull requests. As a result, maintaining the project has become increasingly challenging and has stretched our capacity to its limits. As such, in the near future, we may need to slow down our acceptance of new features and prioritize the stability and quality of existing functions. Please note that new features for VueUse may not be accepted at this time. If you have any new ideas, we suggest that you first incorporate them into your own codebase, iterate on them to suit your needs, and assess their generalizability. If you strongly believe that your ideas are beneficial to the community, you may submit a pull request along with your use cases, and we would be happy to review and discuss them. Thank you for your understanding.

Description

JSON Parsing: Automatically parse JSON strings from EventSource into JavaScript objects
Custom Transformations: Apply user-defined transformation functions to incoming data
Backward Compatibility: All existing functionality remains unchanged, serialization is opt-in

Additional context

This enhancement addresses a common pain point when working with EventSource APIs that send JSON data as strings, requiring manual parsing in every usage. The implementation follows VueUse's existing patterns and maintains full backward compatibility.

OrbisK · 2025-08-10T12:57:55Z

packages/core/useEventSource/index.ts

+
+  /**
+   * Data serialization options
+   */
+  serialization?: {
+    /**
+     * Whether to automatically parse JSON data
+     * @default false
+     */
+    parseJSON?: boolean
+
+    /**
+     * Custom data transformer function
+     * @param data Raw data from EventSource
+     * @returns Transformed data
+     */
+    transform?: (data: any) => any
+  }


IMO we should only have the transform/serializer.

we should add an optional generic to the options and use this for the serializer

serializer?: (v: unknown) => T

the serializer should default to:

serializer: (v) => v

The reason I don't like the parseJSON option is that it doesn't save much.

serialization?: { parseJSON: true }

vs

serializer: (v) => JSON.parse(v)

It is not clear to the user what should happen if we pass both.

serialization?: { parseJSON: true, transform: (v)=> /* ... */ }

thank you for the feedback!

I modified the code according to your suggestion

how is it this time?

OrbisK · 2025-08-10T12:59:40Z

Thank you for your PR.

OrbisK

Looks good so far. Some small adjustments.

Maybe we should rename it to: serializer like useBase64

packages/core/useEventSource/index.ts

imddc · 2025-08-11T08:14:10Z

Looks good so far. Some small adjustments.

Maybe we should rename it to: serializer like useBase64

Thank you！
I have adopted your suggestion, and it looks much better!

OrbisK · 2025-08-11T08:39:26Z

There are no new commits. Maybe you forgot to push 😅

imddc · 2025-08-12T00:47:03Z

There are no new commits. Maybe you forgot to push 😅

I forgot last time. Could you please do the code review again?

OrbisK · 2025-08-12T06:59:44Z

packages/core/useEventSource/index.ts

@@ -183,14 +186,14 @@ export function useEventSource<Events extends string[], Data = any>(

    es.onmessage = (e: MessageEvent) => {
      event.value = null
-      data.value = e.data
+      data.value = serialization(e.data) || null


Suggested change

data.value = serialization(e.data) || null

data.value = serialization(e.data) ?? null

OrbisK · 2025-08-12T06:59:57Z

packages/core/useEventSource/index.ts

+        data.value = serialization(e.data) || null
        lastEventId.value = e.lastEventId || null


Suggested change

data.value = serialization(e.data) || null

lastEventId.value = e.lastEventId || null

data.value = serialization(e.data) ?? null

lastEventId.value = e.lastEventId ?? null

OrbisK · 2025-08-12T07:00:59Z

packages/core/useEventSource/index.ts

  const event: ShallowRef<string | null> = shallowRef(null)
-  const data: ShallowRef<Data | null> = shallowRef(null)
+  const data: ShallowRef<Data | TransformedData | null> = shallowRef(null)


Suggested change

const data: ShallowRef<Data | TransformedData | null> = shallowRef(null)

const data: ShallowRef<TransformedData | null> = shallowRef(null)

imddc · 2025-08-12T07:19:17Z

how about now?

OrbisK · 2025-08-12T07:33:41Z

packages/core/useEventSource/index.ts

  /**
   * Reference to the latest data received via the EventSource,
   * can be watched to respond to incoming messages
   */
-  data: ShallowRef<Data | null>
+  data: ShallowRef<Data | TransformedData | null>


Suggested change

data: ShallowRef<Data | TransformedData | null>

data: ShallowRef<TransformedData | null>

sorry, overlooked this one 🫠

OrbisK

lgtm!

Thank you!

OrbisK · 2025-08-13T09:07:56Z

packages/core/useEventSource/index.md

+  'https://event-source-url',
+  [],
+  {
+    serialization: (rawData) => JSON.parse(rawData),


We held an internal discussion. We want to use the serialiser to ensure consistency with the other composables.

Could you please adjust the PR?

imddc added 3 commits August 10, 2025 20:14

feat(useEventSource): add serialization options for data processing

3487bf8

test(useEventSource): add tests for serialization functionality

c0696aa

docs(useEventSource): add documentation for serialization feature

644c6a4

dosubot bot added size:L This PR changes 100-499 lines, ignoring generated files. enhancement New feature or request labels Aug 10, 2025

OrbisK requested changes Aug 10, 2025

View reviewed changes

refactor(useEventSource): use another way to use seriallization

81b5656

dosubot bot added size:M This PR changes 30-99 lines, ignoring generated files. and removed size:L This PR changes 100-499 lines, ignoring generated files. labels Aug 10, 2025

imddc changed the title ~~Feat/enhance useEventSource~~ feat(useEventSource): add transformer Aug 11, 2025

OrbisK requested changes Aug 11, 2025

View reviewed changes

imddc requested a review from OrbisK August 11, 2025 08:14

feat(useEventSource): rename to serilazation

d80ca06

OrbisK requested changes Aug 12, 2025

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fix(useEventSource): fix type

6b603a8

OrbisK requested changes Aug 12, 2025

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fix(useEventSource): complete the missing types

f115644

imddc requested a review from OrbisK August 12, 2025 08:14

OrbisK approved these changes Aug 12, 2025

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OrbisK requested review from 43081j and ilyaliao August 12, 2025 08:17

dosubot bot added the lgtm This PR has been approved by a maintainer label Aug 12, 2025

OrbisK requested changes Aug 13, 2025

View reviewed changes

dosubot bot removed the lgtm This PR has been approved by a maintainer label Aug 13, 2025

	data.value = serialization(e.data) \|\| null
	data.value = serialization(e.data) ?? null

		data.value = serialization(e.data) \|\| null
		lastEventId.value = e.lastEventId \|\| null

	const data: ShallowRef<Data \| TransformedData \| null> = shallowRef(null)
	const data: ShallowRef<TransformedData \| null> = shallowRef(null)

	data: ShallowRef<Data \| TransformedData \| null>
	data: ShallowRef<TransformedData \| null>

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feat(useEventSource): add transformer #4953

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feat(useEventSource): add transformer #4953

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imddc commented Aug 10, 2025

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imddc commented Aug 11, 2025

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