fix: preproccessor ui and expanding preprocessor support (#6872)

* preproccessor php

* fix

* ok

* remove folder

* chore: publish parser

---------

Co-authored-by: HugoCasa <hugo@casademont.ch>

backend/parsers/windmill-parser-php/src/lib.rs

@@ -44,23 +44,41 @@ fn parse_default_expr(e: Expression) -> Option<Value> {
 
 pub fn parse_php_signature(
     code: &str,
-    override_main: Option<String>,
+    override_entrypoint: Option<String>,
 ) -> anyhow::Result<MainArgSignature> {
-    let main_name = override_main.unwrap_or("main".to_string());
+    let entrypoint_fn_name = override_entrypoint.unwrap_or("main".to_string());
 
     let ast = parser::parse(code)
         .map_err(|e| anyhow::anyhow!("Error parsing code: {}", e.to_string()))?;
 
-    let params = ast.into_iter().find_map(|x| match x {
-        Statement::Function(FunctionStatement {
-            name,
-            parameters: FunctionParameterList { parameters, .. },
-            ..
-        }) if name.to_string() == main_name => Some(parameters),
-        _ => None,
-    });
+    let mut entrypoint_params = None;
+    let mut has_preprocessor = None;
+    for node in ast.into_iter() {
+        match node {
+            Statement::Function(FunctionStatement {
+                name,
+                parameters: FunctionParameterList { parameters, .. },
+                ..
+            }) => {
+                let fn_name = name.to_string();
 
-    if let Some(params) = params {
+                if has_preprocessor.is_none() && fn_name == "preprocessor" {
+                    has_preprocessor = Some(true);
+                }
+
+                if entrypoint_params.is_none() && fn_name == entrypoint_fn_name {
+                    entrypoint_params = Some(parameters);
+                }
+
+                if has_preprocessor.is_some() && entrypoint_params.is_some() {
+                    break;
+                }
+            }
+            _ => {}
+        };
+    }
+
+    if let Some(params) = entrypoint_params {
         let args = params
             .into_iter()
             .map(|x| {
@@ -82,7 +100,7 @@ pub fn parse_php_signature(
             star_kwargs: false,
             args,
             no_main_func: Some(false),
-            has_preprocessor: None,
+            has_preprocessor,
         })
     } else {
         Ok(MainArgSignature {
@@ -90,7 +108,7 @@ pub fn parse_php_signature(
             star_kwargs: false,
             args: vec![],
             no_main_func: Some(true),
-            has_preprocessor: None,
+            has_preprocessor,
         })
     }
 }

backend/parsers/windmill-parser-wasm/src/lib.rs

@@ -134,8 +134,11 @@ pub fn parse_graphql(code: &str) -> String {
 
 #[cfg(feature = "php-parser")]
 #[wasm_bindgen]
-pub fn parse_php(code: &str) -> String {
-    wrap_sig(windmill_parser_php::parse_php_signature(code, None))
+pub fn parse_php(code: &str, main_override: Option<String>) -> String {
+    wrap_sig(windmill_parser_php::parse_php_signature(
+        code,
+        main_override,
+    ))
 }
 
 #[cfg(feature = "rust-parser")]

backend/windmill-worker/src/worker_flow.rs

@@ -2232,7 +2232,7 @@ async fn push_next_flow_job(
             }
         });
 
-    // if this is an empty module without preprocessor of if the module has already been completed, successfully, update the parent flow
+    // if this is an empty module without preprocessor or if the module has already been completed, successfully, update the parent flow
     if (flow.modules.is_empty() && !step.is_preprocessor_step())
         || matches!(status_module, FlowStatusModule::Success { .. })
     {
@@ -3717,11 +3717,13 @@ pub struct JobPayloadWithTag {
     pub timeout: Option<i32>,
     pub on_behalf_of: Option<OnBehalfOf>,
 }
+#[derive(Debug)]
 enum ContinuePayload {
     SingleJob(JobPayloadWithTag),
     ParallelJobs(Vec<JobPayloadWithTag>),
 }
 
+#[derive(Debug)]
 enum NextFlowTransform {
     EmptyInnerFlows { branch_chosen: Option<BranchChosen> },
     Continue(ContinuePayload, NextStatus),

cli/wasm/php/windmill_parser_wasm.d.ts

@@ -1,3 +1,3 @@
 /* tslint:disable */
 /* eslint-disable */
-export function parse_php(code: string): string;
+export function parse_php(code: string, main_override?: string | null): string;

cli/wasm/php/windmill_parser_wasm.js

@@ -56,30 +56,41 @@ function passStringToWasm0(arg, malloc, realloc) {
     return ptr;
 }
 
-const cachedTextDecoder = (typeof TextDecoder !== 'undefined' ? new TextDecoder('utf-8', { ignoreBOM: true, fatal: true }) : { decode: () => { throw Error('TextDecoder not available') } } );
+function isLikeNone(x) {
+    return x === undefined || x === null;
+}
+
+let cachedTextDecoder = (typeof TextDecoder !== 'undefined' ? new TextDecoder('utf-8', { ignoreBOM: true, fatal: true }) : { decode: () => { throw Error('TextDecoder not available') } } );
 
 if (typeof TextDecoder !== 'undefined') { cachedTextDecoder.decode(); };
 
+function decodeText(ptr, len) {
+    return cachedTextDecoder.decode(getUint8ArrayMemory0().subarray(ptr, ptr + len));
+}
+
 function getStringFromWasm0(ptr, len) {
     ptr = ptr >>> 0;
-    return cachedTextDecoder.decode(getUint8ArrayMemory0().subarray(ptr, ptr + len));
+    return decodeText(ptr, len);
 }
 /**
  * @param {string} code
+ * @param {string | null} [main_override]
  * @returns {string}
  */
-export function parse_php(code) {
-    let deferred2_0;
-    let deferred2_1;
+export function parse_php(code, main_override) {
+    let deferred3_0;
+    let deferred3_1;
     try {
         const ptr0 = passStringToWasm0(code, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
         const len0 = WASM_VECTOR_LEN;
-        const ret = wasm.parse_php(ptr0, len0);
-        deferred2_0 = ret[0];
-        deferred2_1 = ret[1];
+        var ptr1 = isLikeNone(main_override) ? 0 : passStringToWasm0(main_override, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+        var len1 = WASM_VECTOR_LEN;
+        const ret = wasm.parse_php(ptr0, len0, ptr1, len1);
+        deferred3_0 = ret[0];
+        deferred3_1 = ret[1];
         return getStringFromWasm0(ret[0], ret[1]);
     } finally {
-        wasm.__wbindgen_free(deferred2_0, deferred2_1, 1);
+        wasm.__wbindgen_free(deferred3_0, deferred3_1, 1);
     }
 }
 

cli/wasm/php/windmill_parser_wasm_bg.wasm.d.ts

@@ -1,7 +1,7 @@
 /* tslint:disable */
 /* eslint-disable */
 export const memory: WebAssembly.Memory;
-export const parse_php: (a: number, b: number) => [number, number];
+export const parse_php: (a: number, b: number, c: number, d: number) => [number, number];
 export const __wbindgen_export_0: WebAssembly.Table;
 export const __wbindgen_malloc: (a: number, b: number) => number;
 export const __wbindgen_realloc: (a: number, b: number, c: number, d: number) => number;

frontend/package-lock.json

@@ -77,7 +77,7 @@
 				"windmill-parser-wasm-go": "1.510.1",
 				"windmill-parser-wasm-java": "1.510.1",
 				"windmill-parser-wasm-nu": "1.510.1",
-				"windmill-parser-wasm-php": "1.510.1",
+				"windmill-parser-wasm-php": "1.574.1",
 				"windmill-parser-wasm-py": "1.538.0",
 				"windmill-parser-wasm-regex": "1.565.0",
 				"windmill-parser-wasm-ruby": "1.526.1",
@@ -13749,9 +13749,9 @@
 			"integrity": "sha512-AJLFiUy6af+LpUe7CddDo4+JOmw3c0K/1iOWh8NdTwXcLDj90lL6089mdsVo1apyloLgrTbcuFDzZMXVGBgtCg=="
 		},
 		"node_modules/windmill-parser-wasm-php": {
-			"version": "1.510.1",
-			"resolved": "https://registry.npmjs.org/windmill-parser-wasm-php/-/windmill-parser-wasm-php-1.510.1.tgz",
-			"integrity": "sha512-qM+yeaqPdMuAaPpqND31ZabpeHlPxxtmRWLs11cGHOCHU32FIaZ92/icNUoAxgBhdJjRhR4GXaeZG32nWit2cg=="
+			"version": "1.574.1",
+			"resolved": "https://registry.npmjs.org/windmill-parser-wasm-php/-/windmill-parser-wasm-php-1.574.1.tgz",
+			"integrity": "sha512-COyid6B1RYs+bpzUCInsA4HY/WZkpDLfkQ90+AqU/TVTpzYSbAC2JCbIwy0cRElBvlhI4bQ+9Wg6hSQKMpEkpA=="
 		},
 		"node_modules/windmill-parser-wasm-py": {
 			"version": "1.538.0",

frontend/package.json

@@ -142,7 +142,7 @@
 		"windmill-parser-wasm-go": "1.510.1",
 		"windmill-parser-wasm-java": "1.510.1",
 		"windmill-parser-wasm-nu": "1.510.1",
-		"windmill-parser-wasm-php": "1.510.1",
+		"windmill-parser-wasm-php": "1.574.1",
 		"windmill-parser-wasm-py": "1.538.0",
 		"windmill-parser-wasm-regex": "1.565.0",
 		"windmill-parser-wasm-ruby": "1.526.1",

frontend/src/lib/components/Editor.svelte

@@ -92,7 +92,7 @@
 	import { aiChatManager } from './copilot/chat/AIChatManager.svelte'
 	import type { Selection } from 'monaco-editor'
 	import { getDbSchemas } from './apps/components/display/dbtable/utils'
-	import { PYTHON_PREPROCESSOR_MODULE_CODE, TS_PREPROCESSOR_MODULE_CODE } from '$lib/script_helpers'
+	import { canHavePreprocessor, getPreprocessorModuleCode } from '$lib/script_helpers'
 	import { setMonacoTypescriptOptions } from './monacoLanguagesOptions'
 	import { copilotInfo } from '$lib/aiStore'
 	// import EditorTheme from './EditorTheme.svelte'
@@ -620,12 +620,18 @@
 	}
 
 	let preprocessorCompletor: IDisposable | undefined = undefined
-	function addPreprocessorCompletions(lang: 'typescript' | 'python') {
+	function addPreprocessorCompletions(lang: string) {
 		if (preprocessorCompletor) {
 			preprocessorCompletor.dispose()
 		}
-		const preprocessorCode =
-			lang === 'typescript' ? TS_PREPROCESSOR_MODULE_CODE : PYTHON_PREPROCESSOR_MODULE_CODE
+
+		const windmillLang = lang === 'typescript' ? 'deno' : lang === 'python' ? 'python3' : lang
+		const preprocessorCode = getPreprocessorModuleCode(windmillLang as ScriptLang)
+
+		if (!preprocessorCode) {
+			return
+		}
+
 		preprocessorCompletor = languages.registerCompletionItemProvider(lang, {
 			provideCompletionItems: function (model, position) {
 				const word = model.getWordUntilPosition(position)
@@ -1653,8 +1659,8 @@
 	})
 
 	$effect(() => {
-		initialized && (lang === 'typescript' || lang === 'python') && enablePreprocessorSnippet
-			? untrack(() => addPreprocessorCompletions(lang as 'typescript' | 'python'))
+		initialized && canHavePreprocessor(lang) && enablePreprocessorSnippet
+			? untrack(() => addPreprocessorCompletions(lang))
 			: preprocessorCompletor?.dispose()
 	})
 

frontend/src/lib/components/ScriptBuilder.svelte

@@ -15,7 +15,12 @@
 		WorkerService
 	} from '$lib/gen'
 	import { inferArgs } from '$lib/infer'
-	import { initialCode } from '$lib/script_helpers'
+	import {
+		initialCode,
+		canHavePreprocessor,
+		getPreprocessorFullCode,
+		getMainFunctionPattern
+	} from '$lib/script_helpers'
 	import AIFormSettings from './copilot/AIFormSettings.svelte'
 	import {
 		defaultScripts,
@@ -80,12 +85,6 @@
 	import DeployOverrideConfirmationModal from '$lib/components/common/confirmationModal/DeployOverrideConfirmationModal.svelte'
 	import TriggersEditor from './triggers/TriggersEditor.svelte'
 	import type { ScheduleTrigger, TriggerContext } from './triggers'
-	import {
-		TS_PREPROCESSOR_MODULE_CODE,
-		TS_PREPROCESSOR_SCRIPT_INTRO,
-		PYTHON_PREPROCESSOR_MODULE_CODE,
-		PYTHON_PREPROCESSOR_SCRIPT_INTRO
-	} from '$lib/script_helpers'
 	import CaptureTable from './triggers/CaptureTable.svelte'
 	import type { SavedAndModifiedValue } from './common/confirmationModal/unsavedTypes'
 	import DeployButton from './DeployButton.svelte'
@@ -313,7 +312,7 @@
 		{
 			value: 'preprocessor',
 			title: 'Preprocessor',
-			desc: 'Transform incoming requests before they are passed to the flow.',
+			desc: 'Transform incoming requests before they are passed to the main entrypoint.',
 			documentationLink: 'https://www.windmill.dev/docs/core_concepts/preprocessors',
 			Icon: Shuffle
 		}
@@ -853,13 +852,10 @@
 	function addPreprocessor() {
 		const code = editor?.getCode()
 		if (code) {
-			const preprocessorCode =
-				script.language === 'python3'
-					? PYTHON_PREPROCESSOR_SCRIPT_INTRO + PYTHON_PREPROCESSOR_MODULE_CODE
-					: TS_PREPROCESSOR_SCRIPT_INTRO + TS_PREPROCESSOR_MODULE_CODE
-			const mainIndex = code.indexOf(
-				script.language === 'python3' ? 'def main' : 'export async function main'
-			)
+			const preprocessorCode = getPreprocessorFullCode(script.language, false)
+			const mainPattern = getMainFunctionPattern(script.language)
+			const mainIndex = code.indexOf(mainPattern)
+
 			if (mainIndex === -1) {
 				editor?.setCode(code + preprocessorCode)
 			} else {
@@ -1139,7 +1135,8 @@
 															btnClasses={isPicked ? '' : 'm-[1px]'}
 															on:click={() => onScriptLanguageTrigger(lang)}
 															disabled={lockedLanguage ||
-																(enterpriseLangs.includes(lang) && !$enterpriseLicense)}
+																(enterpriseLangs.includes(lang) && !$enterpriseLicense) ||
+																(script.kind == 'preprocessor' && !canHavePreprocessor(lang))}
 															startIcon={{
 																icon: LanguageIcon,
 																props: { lang }
@@ -1667,9 +1664,7 @@
 									newItem={initialPath == ''}
 									isFlow={false}
 									{hasPreprocessor}
-									canHavePreprocessor={script.language === 'bun' ||
-										script.language === 'deno' ||
-										script.language === 'python3'}
+									canHavePreprocessor={canHavePreprocessor(script.language)}
 									args={hasPreprocessor && selectedInputTab !== 'preprocessor' ? {} : args}
 									isDeployed={savedScript && !savedScript?.draft_only}
 									schema={script.schema}

frontend/src/lib/components/ScriptEditor.svelte

@@ -48,6 +48,7 @@
 	import { aiChatManager, AIMode } from './copilot/chat/AIChatManager.svelte'
 	import { triggerableByAI } from '$lib/actions/triggerableByAI.svelte'
 	import AssetsDropdownButton from './assets/AssetsDropdownButton.svelte'
+	import { canHavePreprocessor } from '$lib/script_helpers'
 	import { assetEq, type AssetWithAltAccessType } from './assets/lib'
 	import { editor as meditor } from 'monaco-editor'
 	import type { ReviewChangesOpts } from './copilot/chat/monaco-adapter'
@@ -741,7 +742,7 @@
 									<CaptureTable
 										bind:this={captureTable}
 										{hasPreprocessor}
-										canHavePreprocessor={lang === 'bun' || lang === 'deno' || lang === 'python3'}
+										canHavePreprocessor={canHavePreprocessor(lang)}
 										isFlow={false}
 										path={stablePathForCaptures}
 										canEdit={true}

frontend/src/lib/components/flows/content/FlowInputs.svelte

@@ -18,6 +18,7 @@
 	import type { SupportedLanguage } from '$lib/common'
 	import DefaultScripts from '$lib/components/DefaultScripts.svelte'
 	import type { FlowBuilderWhitelabelCustomUi } from '$lib/components/custom_ui'
+	import { canHavePreprocessor } from '$lib/script_helpers'
 
 	interface Props {
 		failureModule: boolean
@@ -57,18 +58,51 @@
 	)
 
 	function displayLang(lang: SupportedLanguage | 'docker', kind: string) {
-		if (lang == 'bun' || lang == 'python3' || lang == 'deno') {
+		if (preprocessorModule) {
+			return canHavePreprocessor(lang as SupportedLanguage)
+		}
+
+		if (failureModule || kind === 'trigger') {
+			if (
+				[
+					'postgresql',
+					'mysql',
+					'bigquery',
+					'snowflake',
+					'mssql',
+					'graphql',
+					'duckdb',
+					'oracledb'
+				].includes(lang)
+			) {
+				return false
+			}
 			return true
 		}
 
-		if (lang == 'go') {
-			return (kind == 'script' || kind == 'trigger' || failureModule) && !preprocessorModule
+		if (kind === 'script') {
+			return lang !== 'docker'
 		}
 
-		if (lang == 'bash' || lang == 'nativets') {
-			return kind == 'script' && !preprocessorModule
+		if (kind === 'approval') {
+			if (
+				[
+					'postgresql',
+					'mysql',
+					'bigquery',
+					'snowflake',
+					'mssql',
+					'graphql',
+					'duckdb',
+					'oracledb'
+				].includes(lang)
+			) {
+				return false
+			}
+			return true
 		}
-		return kind == 'script' && !failureModule && !preprocessorModule
+
+		return false
 	}
 
 	let customUi: undefined | FlowBuilderWhitelabelCustomUi = getContext('customUi')

frontend/src/lib/components/flows/content/FlowInputsQuick.svelte

@@ -30,6 +30,12 @@
 	import GenAiQuick from './GenAiQuick.svelte'
 	import FlowToplevelNode from '../pickers/FlowToplevelNode.svelte'
 	import { copilotInfo } from '$lib/aiStore'
+	import {
+		canHavePreprocessor,
+		canHaveTrigger,
+		canHaveApproval,
+		canHaveFailure
+	} from '$lib/script_helpers'
 
 	const dispatch = createEventDispatcher()
 
@@ -94,17 +100,17 @@
 		kind: 'script' | 'flow' | 'approval' | 'trigger' | 'preprocessor' | 'failure'
 	) {
 		if (kind == 'trigger') {
-			return ['python3', 'bun', 'deno', 'go'].includes(lang)
+			return canHaveTrigger(lang as SupportedLanguage)
 		} else if (kind == 'script') {
 			return true
 		} else if (kind == 'approval') {
-			return ['python3', 'bun', 'deno'].includes(lang)
+			return canHaveApproval(lang as SupportedLanguage)
 		} else if (kind == 'flow') {
 			return false
 		} else if (kind == 'preprocessor') {
-			return ['python3', 'bun', 'deno'].includes(lang)
+			return canHavePreprocessor(lang as SupportedLanguage)
 		} else if (kind == 'failure') {
-			return ['python3', 'bun', 'deno', 'go'].includes(lang)
+			return canHaveFailure(lang as SupportedLanguage)
 		}
 	}
 

frontend/src/lib/infer.ts

@@ -23,7 +23,11 @@ import initPythonParser, { parse_assets_py, parse_python } from 'windmill-parser
 import initGoParser, { parse_go } from 'windmill-parser-wasm-go'
 import initPhpParser, { parse_php } from 'windmill-parser-wasm-php'
 import initRustParser, { parse_rust } from 'windmill-parser-wasm-rust'
-import initYamlParser, { parse_assets_ansible, parse_ansible, parse_ansible_delegate } from 'windmill-parser-wasm-yaml'
+import initYamlParser, {
+	parse_assets_ansible,
+	parse_ansible,
+	parse_ansible_delegate
+} from 'windmill-parser-wasm-yaml'
 import initCSharpParser, { parse_csharp } from 'windmill-parser-wasm-csharp'
 import initNuParser, { parse_nu } from 'windmill-parser-wasm-nu'
 import initJavaParser, { parse_java } from 'windmill-parser-wasm-java'
@@ -244,7 +248,7 @@ export async function inferArgs(
 			inferedSchema = JSON.parse(parse_powershell(code))
 		} else if (language == 'php') {
 			await initWasmPhp()
-			inferedSchema = JSON.parse(parse_php(code))
+			inferedSchema = JSON.parse(parse_php(code, mainOverride))
 		} else if (language == 'rust') {
 			await initWasmRust()
 			inferedSchema = JSON.parse(parse_rust(code))

frontend/src/lib/script_helpers.ts

@@ -969,6 +969,86 @@ def preprocessor(event: Event):
     }
 `
 
+export const PHP_PREPROCESSOR_SCRIPT_INTRO = `<?php
+/**
+ * Trigger preprocessor
+ *
+ * ⚠️ This function runs BEFORE the main function.
+ *
+ * It processes raw trigger data from various sources (webhook, custom HTTP route, SQS, WebSocket, Kafka, NATS, MQTT, Postgres, or email)
+ * before passing it to \`main\`. This separates the trigger logic from the main logic and keeps the auto-generated runnable UI clean.
+ *
+ * The returned object defines the parameter values passed to \`main()\`.
+ * e.g., ['b' => 1, 'a' => 2] → Calls \`main(2, 1)\`, assuming \`main\` is defined as \`main($a, $b)\`.
+ * Ensure that the parameter names in \`main\` match the keys in the returned array.
+ * 
+ * Learn more: https://www.windmill.dev/docs/core_concepts/preprocessors
+ */
+
+`
+
+export const PHP_PREPROCESSOR_FLOW_INTRO = `<?php
+/**
+ * Trigger preprocessor
+ *
+ * It processes raw trigger data from various sources (webhook, custom HTTP route, SQS, WebSocket, Kafka, NATS, MQTT, Postgres, or email) 
+ * before passing it to the flow. This separates the trigger logic from the flow logic and keeps the auto-generated UI clean.
+ * 
+ * The returned object determines the parameter values passed to the flow.
+ * e.g., ['b' => 1, 'a' => 2] → Calls the flow with \`a = 2\` and \`b = 1\`, assuming the flow has two inputs called \`a\` and \`b\`.
+ * Ensure that the input names of the flow match the keys in the returned array.
+ * 
+ * Learn more: https://www.windmill.dev/docs/core_concepts/preprocessors
+ */
+
+`
+
+export const PHP_PREPROCESSOR_MODULE_CODE = `function preprocessor(object $event) {
+    // $event can be one of the following types:
+    // 
+    // Webhook event:
+    // ['kind' => 'webhook', 'body' => [...], 'raw_string' => '...', 'query' => [...], 'headers' => [...]]
+    // 
+    // HTTP event:
+    // ['kind' => 'http', 'body' => [...], 'raw_string' => '...', 'route' => '...', 'path' => '...', 
+    //  'method' => '...', 'params' => [...], 'query' => [...], 'headers' => [...]]
+    // 
+    // Email event:
+    // ['kind' => 'email', 'parsed_email' => [...], 'raw_email' => '...', 'email_extra_args' => [...]]
+    // 
+    // WebSocket event:
+    // ['kind' => 'websocket', 'msg' => '...', 'url' => '...']
+    // 
+    // Kafka event:
+    // ['kind' => 'kafka', 'payload' => '...', 'brokers' => [...], 'topic' => '...', 'group_id' => '...']
+    // 
+    // NATS event:
+    // ['kind' => 'nats', 'payload' => '...', 'servers' => [...], 'subject' => '...', 
+    //  'headers' => [...], 'status' => 200, 'description' => '...', 'length' => 100]
+    // 
+    // SQS event:
+    // ['kind' => 'sqs', 'msg' => '...', 'queue_url' => '...', 'message_id' => '...', 
+    //  'receipt_handle' => '...', 'attributes' => [...], 'message_attributes' => [...]]
+    // 
+    // MQTT event:
+    // ['kind' => 'mqtt', 'payload' => '...', 'topic' => '...', 'retain' => true, 'pkid' => 1, 
+    //  'qos' => 1, 'v5' => [...]]
+    // 
+    // GCP event:
+    // ['kind' => 'gcp', 'payload' => '...', 'message_id' => '...', 'subscription' => '...', 
+    //  'ordering_key' => '...', 'attributes' => [...], 'delivery_type' => 'push', 
+    //  'headers' => [...], 'publish_time' => '...', 'ack_id' => '...']
+    // 
+    // Postgres event:
+    // ['kind' => 'postgres', 'transaction_type' => 'insert', 'schema_name' => '...', 
+    //  'table_name' => '...', 'old_row' => [...], 'row' => [...]]
+
+    return [
+        // return the args to be passed to the runnable
+    ];
+}
+`
+
 const DOCKER_INIT_CODE = `# shellcheck shell=bash
 # docker
 # The annotation "docker" above is important, it tells windmill that after 
@@ -1226,7 +1306,8 @@ export const INITIAL_CODE = {
 		script: ORACLEDB_INIT_CODE
 	},
 	php: {
-		script: PHP_INIT_CODE
+		script: PHP_INIT_CODE,
+		preprocessor: PHP_PREPROCESSOR_FLOW_INTRO + PHP_PREPROCESSOR_MODULE_CODE
 	},
 	rust: {
 		script: RUST_INIT_CODE
@@ -1349,6 +1430,9 @@ export function initialCode(
 	} else if (language == 'duckdb') {
 		return INITIAL_CODE.duckdb.script
 	} else if (language == 'php') {
+		if (kind == 'preprocessor') {
+			return INITIAL_CODE.php.preprocessor
+		}
 		return INITIAL_CODE.php.script
 	} else if (language == 'rust') {
 		return INITIAL_CODE.rust.script
@@ -1420,3 +1504,115 @@ export function getResetCode(
 		return initialCode(language, kind, subkind)
 	}
 }
+
+export const PREPROCESSOR_SUPPORTED_LANGUAGES = [
+	'typescript',
+	'python',
+	'python3',
+	'deno',
+	'bun',
+	'php'
+] as const
+
+export function canHavePreprocessor(language: string | undefined): boolean {
+	if (!language) {
+		return false
+	}
+
+	return PREPROCESSOR_SUPPORTED_LANGUAGES.includes(language as any)
+}
+
+export function canHaveTrigger(language: SupportedLanguage | undefined): boolean {
+	if (!language) {
+		return false
+	}
+
+	return ['python3', 'bun', 'deno', 'go'].includes(language)
+}
+
+export function canHaveApproval(language: SupportedLanguage | undefined): boolean {
+	if (!language) {
+		return false
+	}
+
+	return ['python3', 'bun', 'deno'].includes(language)
+}
+
+export function canHaveFailure(language: SupportedLanguage | undefined): boolean {
+	if (!language) {
+		return false
+	}
+
+	return ['python3', 'bun', 'deno', 'go'].includes(language)
+}
+
+export function getPreprocessorIntro(
+	language: SupportedLanguage | 'docker' | 'bunnative' | undefined,
+	isFlow: boolean = false
+): string {
+	if (!language || !PREPROCESSOR_SUPPORTED_LANGUAGES.includes(language as any)) {
+		return ''
+	}
+
+	switch (language) {
+		case 'python3':
+			return isFlow ? PYTHON_PREPROCESSOR_FLOW_INTRO : PYTHON_PREPROCESSOR_SCRIPT_INTRO
+		case 'deno':
+		case 'bun':
+			return isFlow ? TS_PREPROCESSOR_FLOW_INTRO : TS_PREPROCESSOR_SCRIPT_INTRO
+		case 'php':
+			return isFlow ? PHP_PREPROCESSOR_FLOW_INTRO : PHP_PREPROCESSOR_SCRIPT_INTRO
+		default:
+			return ''
+	}
+}
+
+export function getPreprocessorModuleCode(
+	language: SupportedLanguage | 'docker' | 'bunnative' | undefined
+): string {
+	if (!language || !PREPROCESSOR_SUPPORTED_LANGUAGES.includes(language as any)) {
+		return ''
+	}
+
+	switch (language) {
+		case 'python3':
+			return PYTHON_PREPROCESSOR_MODULE_CODE
+		case 'deno':
+		case 'bun':
+			return TS_PREPROCESSOR_MODULE_CODE
+		case 'php':
+			return PHP_PREPROCESSOR_MODULE_CODE
+		default:
+			return ''
+	}
+}
+
+export function getPreprocessorFullCode(
+	language: SupportedLanguage | 'docker' | 'bunnative' | undefined,
+	isFlow: boolean = false
+): string {
+	const intro = getPreprocessorIntro(language, isFlow)
+	const moduleCode = getPreprocessorModuleCode(language)
+	return intro + moduleCode
+}
+
+export function getMainFunctionPattern(
+	language: SupportedLanguage | 'docker' | 'bunnative' | undefined
+): string {
+	if (!language) {
+		return ''
+	}
+
+	switch (language) {
+		case 'python3':
+			return 'def main'
+		case 'deno':
+		case 'bun':
+		case 'nativets':
+			return 'export async function main'
+		case 'php':
+			return 'function main'
+		default:
+			return 'main'
+	}
+}