langgenius/dify
1
0
Fork 0
mirror of https://github.com/langgenius/dify.git synced 2026-07-20 19:50:06 -04:00
Code Issues 775 Packages Projects Releases 10 Wiki Activity

Plugin array output variables not visible in Iteration/Template node variable selector due to type case mismatch #20050

New Issue
Closed
opened 2026-02-21 20:05:36 -05:00 by yindo · 1 comment
yindo commented 2026-02-21 20:05:36 -05:00
Owner
Copy Link
Copy Source

Originally created by @ding113 on GitHub (Oct 30, 2025).

Self Checks

  • I have read the Contributing Guide and Language Policy.
  • This is only for bug report, if you would like to ask a question, please head to Discussions.
  • I have searched for existing issues search for existing issues, including closed ones.
  • I confirm that I am using English to submit this report, otherwise it will be closed.
  • 【中文用户 & Non English User】请使用英语提交，否则会被关闭 ：）
  • Please do not modify this template :) and fill in all the required fields.

Dify version

1.9.2

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

  1. Create a plugin tool with the following output schema in YAML:
output_schema:
  type: object
  properties:
    chunks:
      type: array
      items:
        type: string
  1. In the plugin Python code, output the array variable:
result = ["item1", "item2", "item3"]
yield self.create_variable_message("chunks", result)

  1. Create a workflow:

    • Add the plugin tool node
    • Add an Iteration node
    • Try to select the plugin's chunks output as the iteration input

  2. Expected: The chunks variable appears in the variable selector dropdown

  3. Actual: The chunks variable is NOT visible in the selector

  4. However: If you connect the same chunks variable to an End node, it IS visible and works correctly.

The Problem

The strict string comparison varPayload.type ∈ [VarType.arrayString, ...] fails because:

  • Tool node generates: "Array[string]" (capital A)
  • Filter expects: "array[string]" (lowercase a)
  • Result: "Array[string]" !== "array[string]" → variable is filtered out

✔️ Expected Behavior

The chunks variable appears in the variable selector dropdown

❌ Actual Behavior

The chunks variable is NOT visible in the selector

Originally created by @ding113 on GitHub (Oct 30, 2025). ### Self Checks - [x] I have read the [Contributing Guide](https://github.com/langgenius/dify/blob/main/CONTRIBUTING.md) and [Language Policy](https://github.com/langgenius/dify/issues/1542). - [x] This is only for bug report, if you would like to ask a question, please head to [Discussions](https://github.com/langgenius/dify/discussions/categories/general). - [x] I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones. - [x] I confirm that I am using English to submit this report, otherwise it will be closed. - [x] 【中文用户 & Non English User】请使用英语提交，否则会被关闭 ：） - [x] Please do not modify this template :) and fill in all the required fields. ### Dify version 1.9.2 ### Cloud or Self Hosted Self Hosted (Docker) ### Steps to reproduce 1. Create a plugin tool with the following output schema in YAML: ```yaml output_schema: type: object properties: chunks: type: array items: type: string ``` 2. In the plugin Python code, output the array variable: ```python result = ["item1", "item2", "item3"] yield self.create_variable_message("chunks", result) ``` 3. Create a workflow: - Add the plugin tool node - Add an Iteration node - Try to select the plugin's `chunks` output as the iteration input 4. **Expected**: The `chunks` variable appears in the variable selector dropdown 5. **Actual**: The `chunks` variable is NOT visible in the selector 6. **However**: If you connect the same `chunks` variable to an End node, it IS visible and works correctly. ### The Problem The strict string comparison `varPayload.type` ∈ `[VarType.arrayString, ...]` fails because: - Tool node generates: `"Array[string]"` (capital A) - Filter expects: `"array[string]"` (lowercase a) - Result: `"Array[string]" !== "array[string]"` → variable is filtered out ### ✔️ Expected Behavior The `chunks` variable appears in the variable selector dropdown ### ❌ Actual Behavior The `chunks` variable is NOT visible in the selector
yindo added the 🐞 bugstale labels 2026-02-21 20:05:36 -05:00
yindo closed this issue 2026-02-21 20:05:36 -05:00
yindo commented 2026-02-21 20:05:36 -05:00
Author
Owner
Copy Link
Copy Source

@dosubot[bot] commented on GitHub (Oct 30, 2025):

This issue is caused by a strict, case-sensitive type string comparison in the variable selector logic for Iteration/Template nodes. When a plugin outputs a variable with type "Array[string]" (capital A), the selector expects "array[string]" (lowercase a), so the variable is filtered out and not shown. This is a known bug in Dify v1.9.2 and has been reported by other users as well.

Recent pull requests show that the Dify team has worked on parameter type normalization and array type handling, introducing utilities to help with type consistency (for example, normalizing types to lowercase and supporting variants like array[string])—see PR #25005 and PR #24390. However, in v1.9.2, the filtering logic does not normalize type strings before comparison, which leads to this bug.

A practical workaround is to use a Template node to convert your array output to a string output, which allows you to select the variable in subsequent nodes. This approach has been confirmed by other users facing similar type mismatch issues in node selectors (example workaround).

Upgrading to a newer version of Dify (if possible) may also help, as recent changes aim to improve type normalization and variable compatibility in workflows.

To reply, just mention @dosu.

How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other  Chat with Dosu Join Discord Share on X

@dosubot[bot] commented on GitHub (Oct 30, 2025): <!-- Answer --> This issue is caused by a strict, case-sensitive type string comparison in the variable selector logic for Iteration/Template nodes. When a plugin outputs a variable with type `"Array[string]"` (capital A), the selector expects `"array[string]"` (lowercase a), so the variable is filtered out and not shown. This is a known bug in Dify v1.9.2 and has been reported by other users as well. Recent pull requests show that the Dify team has worked on parameter type normalization and array type handling, introducing utilities to help with type consistency (for example, normalizing types to lowercase and supporting variants like `array[string]`)—see [PR #25005](https://github.com/langgenius/dify/pull/25005) and [PR #24390](https://github.com/langgenius/dify/pull/24390). However, in v1.9.2, the filtering logic does not normalize type strings before comparison, which leads to this bug. A practical workaround is to use a Template node to convert your array output to a string output, which allows you to select the variable in subsequent nodes. This approach has been confirmed by other users facing similar type mismatch issues in node selectors ([example workaround](https://github.com/langgenius/dify-official-plugins/issues/1091)). Upgrading to a newer version of Dify (if possible) may also help, as recent changes aim to improve type normalization and variable compatibility in workflows. <!-- Dosu Comment Footer --> *To reply, just mention [@dosu](https://go.dosu.dev/dosubot).* --- <sup>How did I do? [Good](https://app.dosu.dev/response-feedback/6f1165ab-6965-40f4-b29d-e966297d3245?feedback_type=great_response) | [Irrelevant](https://app.dosu.dev/response-feedback/6f1165ab-6965-40f4-b29d-e966297d3245?feedback_type=irrelevant_answer) | [Incorrect](https://app.dosu.dev/response-feedback/6f1165ab-6965-40f4-b29d-e966297d3245?feedback_type=incorrect_sources) | [Verbose](https://app.dosu.dev/response-feedback/6f1165ab-6965-40f4-b29d-e966297d3245?feedback_type=too_verbose) | [Hallucination](https://app.dosu.dev/response-feedback/6f1165ab-6965-40f4-b29d-e966297d3245?feedback_type=hallucination) | [Report 🐛](https://app.dosu.dev/response-feedback/6f1165ab-6965-40f4-b29d-e966297d3245?feedback_type=bug_report) | [Other](https://app.dosu.dev/response-feedback/6f1165ab-6965-40f4-b29d-e966297d3245?feedback_type=other)</sup>&nbsp;&nbsp;[![Chat with Dosu](https://dosu.dev/dosu-chat-badge.svg)](https://app.dosu.dev/6088a4f4-073a-43f3-b3d4-4f06fb0c05a0/ask?utm_source=github)&nbsp;[![Join Discord](https://img.shields.io/badge/join-5865F2?logo=discord&logoColor=white&label=)](https://go.dosu.dev/discord-bot)&nbsp;[![Share on X](https://img.shields.io/badge/X-share-black)](https://twitter.com/intent/tweet?text=%40dosu_ai%20helped%20me%20solve%20this%20issue!&url=https%3A//github.com/langgenius/dify/issues/27673)
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
Knowledge Pipeline
Proposal
WIP
cloud
dependencies
feat:webapp
good first issue
outdated
performance
pull-request
Mirrored from GitHub Pull Request
 python:uv
refactor
size:L
stale
status: accepting prs
status: blocked
status: in discussion
stt & tts
vulnerablity
web
wont-fix
🌊 feat:workflow
🌚 invalid
🐞 bug
👻 feat:rag
💪 enhancement
📚 documentation
🔨 feat:tools
🙋‍♂️ question
🙏 help wanted
🤔 cant-reproduce
🤖 feat:agent
No Label stale 🐞 bug
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
yindo
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: langgenius/dify#20050
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?