README
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WASM Source Module
This directory contains example source code for a WASM data source module.
Building
Requires TinyGo:
tinygo build -o quotes.wasm -target wasi quotes.go
Interface
WASM modules must export these functions to work with tinkerdown:
Required
| Export | Signature | Description |
|---|---|---|
fetch |
() -> i32 |
Fetch data, return pointer to JSON array |
get_result_len |
() -> i32 |
Return length of last fetch result |
Optional
| Export | Signature | Description |
|---|---|---|
free_result |
() -> void |
Free memory from last result |
write |
(action_ptr, action_len, data_ptr, data_len) -> i32 |
Handle write ops, return 0=success |
get_error |
() -> i32 |
Pointer to error string |
get_error_len |
() -> i32 |
Length of error string |
Configuration
Options passed to the source in tinkerdown.yaml are available as environment variables:
sources:
quotes:
type: wasm
path: "./sources/quotes.wasm"
options:
category: "inspiration" # Available as os.Getenv("category")
api_key: "${API_KEY}" # Env var substitution works
Data Format
The fetch function must return a pointer to a JSON array of objects:
[
{"id": 1, "text": "Quote text", "author": "Author Name"},
{"id": 2, "text": "Another quote", "author": "Another Author"}
]
Each object becomes a row in the template's .Data array.
Documentation
Source Files
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