Which @angular/* package(s) are relevant/related to the feature request?

core

Description

When using the new experimentalresource, whenever the params changed, value of the resource is cleared and reloaded. There is currently no built in mechanism to provide a custom equals function to check if the new params are equal to the previous one, thus allowing unnecessary reload.

Currently, a workaround requires creating a computed signal with the custom equals function, and using its value as params.

Proposed solution

AparamsEqual field inresources option for a custom equality function to compare params value. Clear existing value and reloadonly when the equality function indicates that params have changed.

const userResource = resource({  params: () => ({/* some complex params */}),  paramsEqual: (prev, curr) => /* custom equality checks */,  loader: ({params}) => fetchUser(params),});

Also, clarify indocumentation that the value will benull (orundefined?) after a new params provided, and before the new value is loaded.

Alternatives considered

Update documentation to emphasis that a computed signal (with custom equal) can also be provided as a params. But this is less intuitive as users expect resources to have similar syntax as other signals, instead of nesting other signals inline. And I don't think this is intended usage anyway.

const userResource = resource({  params: computed(() => ({/* some complex params */}), {equal: customEqualFn}),  loader: ({params}) => fetchUser(params),});