Repository navigation
WW-5849 Design a forward result to replace action chaining - #2129
Draft
lukaszlenart wants to merge 3 commits into
Draft
lukaszlenart wants to merge 3 commits into
lukaszlenart wants to merge 3 commits into
Conversation
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Static forward targets make the forward graph known from configuration, so cycles can be reported when the configuration is built instead of on a user's request. The per-request depth limit stays as the runtime backstop. A per-request time budget was considered instead of the depth limit and rejected: nested forwards overflow the stack long before any useful budget expires, a running action cannot be safely aborted, and a load-dependent limit fails under load and cannot be pinned by a test. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
During the 7.7.0 deprecation phase, chain also logs each target that has not opted in as a forward target, next to the copied properties, so users know which actions to mark before switching. Evolving chain in place towards the forward design (keeping the result type name and flipping its behaviour step by step) was considered and rejected. The per-action work for users is the same in both approaches; in-place evolution saves only the type="chain" -> type="forward" rename, at the cost of several mode constants and their test matrix until 8.0.0, a breaking change to struts.chaining.requireAnnotations (shared with AliasInterceptor), a value-stack isolation step that cannot be phased, and a result type whose meaning changes across releases. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
|
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes WW-5849
What
A design document for a new
forwardresult: a server-side transfer from one action to another within the same request. It is meant to replace action chaining (thechainresult plusChainingInterceptor). Design only; no code yet.Why
The "Is anyone using action chaining?" thread on user@ showed that chaining is still in use, mostly for server-side branching where the next action depends on the current one's state, without an extra browser round-trip.
redirectActionand moving logic into services don't cover that, so chaining can't simply be removed.Chaining also does much more than that hand-off needs: any action can be chained to, the target name is an expression, every value-stack property is copied by name, and the source action stays in the target's value stack. The design keeps the hand-off and makes both boundaries explicit:
<action>attribute)@StrutsParameterrules, plus an explicit hand-off named on both sides; fresh value stack, no property copyingRollout
forward+struts-7.6.dtd;chainunchangedchain, with a log of copied properties as a migration aidchainReview focus
The calls marked in the document that weren't settled in discussion: hand-off applied by a dedicated interceptor after
params, hand-off limited to top-level action setters, depth limit default 5 backed by a startup cycle check on the static forward graph, deprecation one release afterforwardships, and Convention's implicit forward carrying no hand-off values.🤖 Generated with Claude Code