PHP's call_user_func in TypeScript

How to use

Install via yarn add locutus and import: import { call_user_func } from 'locutus/php/funchand/call_user_func'.

Or with CommonJS: const { call_user_func } = require('locutus/php/funchand/call_user_func')

Use a bundler that supports tree-shaking so you only ship the functions you actually use. Vite, webpack, Rollup, and Parcel all handle this. For server-side use this is less of a concern.

Examples

These examples are extracted from test cases that automatically verify our functions against their native counterparts.

#	code	expected result
1	call_user_func('isNaN', 'a')	true

Notes

• Depends on call_user_func_array which in turn depends on the cb that is passed, this function can use eval. The eval input is however checked to only allow valid function names, So it should not be unsafer than uses without eval (seeing as you can) already pass any function to be executed here.

Dependencies

This function uses the following Locutus functions:

• call_user_func_array (php/funchand)

Here's what our current TypeScript equivalent to PHP's call_user_func looks like.

TSTypeScript JSJavaScript TSStandalone TS JSStandalone JS

Copy code

import type { PhpCallableArgs, PhpCallableDescriptor, PhpRuntimeValue } from '../_helpers/_phpTypes.ts'
import { call_user_func_array as callUserFuncArray } from '../funchand/call_user_func_array.ts'

type FunctionArg = PhpRuntimeValue

export function call_user_func<TResult = FunctionArg, TArgs extends PhpCallableArgs = PhpCallableArgs>(
  cb: PhpCallableDescriptor<TArgs, TResult>,
  ...parameters: TArgs
): TResult {
  //  discuss at: https://locutus.io/php/call_user_func/
  // original by: Brett Zamir (https://brett-zamir.me)
  // improved by: Diplom@t (https://difane.com/)
  // improved by: Brett Zamir (https://brett-zamir.me)
  //      note 1: Depends on call_user_func_array which in turn depends on the `cb` that is passed,
  //      note 1: this function can use `eval`.
  //      note 1: The `eval` input is however checked to only allow valid function names,
  //      note 1: So it should not be unsafer than uses without eval (seeing as you can)
  //      note 1: already pass any function to be executed here.
  //   example 1: call_user_func('isNaN', 'a')
  //   returns 1: true

  return callUserFuncArray<TResult, TArgs>(cb, parameters)
}

import { call_user_func_array as callUserFuncArray } from '../funchand/call_user_func_array.ts'

export function call_user_func(cb, ...parameters) {
  //  discuss at: https://locutus.io/php/call_user_func/
  // original by: Brett Zamir (https://brett-zamir.me)
  // improved by: Diplom@t (https://difane.com/)
  // improved by: Brett Zamir (https://brett-zamir.me)
  //      note 1: Depends on call_user_func_array which in turn depends on the `cb` that is passed,
  //      note 1: this function can use `eval`.
  //      note 1: The `eval` input is however checked to only allow valid function names,
  //      note 1: So it should not be unsafer than uses without eval (seeing as you can)
  //      note 1: already pass any function to be executed here.
  //   example 1: call_user_func('isNaN', 'a')
  //   returns 1: true

  return callUserFuncArray(cb, parameters)
}

// php/_helpers/_phpTypes (Locutus helper dependency)
type PhpNullish = null | undefined

type PhpInput = {} | PhpNullish

type PhpScalar = string | number | boolean

type PhpPrimitive = PhpScalar | bigint

type PhpList<T = PhpInput> = T[]

type PhpAssoc<T = PhpInput> = { [key: string]: T }

type PhpArrayLike<T = PhpInput> = PhpList<T> | PhpAssoc<T>

type PhpFunctionValue = (...args: PhpInput[]) => PhpInput

interface PhpRuntimeAssoc {
  [key: string]: PhpRuntimeValue
}

interface PhpRuntimeList extends Array<PhpRuntimeValue> {}

type PhpRuntimeValue = PhpPrimitive | PhpNullish | PhpRuntimeList | PhpRuntimeAssoc | PhpFunctionValue

type PhpCallableArgs = PhpInput[]

type PhpCallable<TArgs extends PhpCallableArgs = PhpCallableArgs, TResult = PhpInput> = (
  ...args: TArgs
) => TResult

type PhpCallableScope = PhpInput

type PhpCallableTuple<TArgs extends PhpCallableArgs = PhpCallableArgs, TResult = PhpInput> = readonly [
  PhpCallableScope,
  string | PhpCallable<TArgs, TResult>,
]

type PhpCallableDescriptor<TArgs extends PhpCallableArgs = PhpCallableArgs, TResult = PhpInput> =
  | string
  | PhpCallable<TArgs, TResult>
  | PhpCallableTuple<TArgs, TResult>

function isObjectLike(value: PhpInput): value is PhpArrayLike<PhpInput> {
  return typeof value === 'object' && value !== null
}

function isPhpCallable<TArgs extends PhpCallableArgs = PhpCallableArgs, TResult = PhpInput>(
  value: PhpInput,
): value is PhpCallable<TArgs, TResult> {
  return typeof value === 'function'
}

// php/_helpers/_phpRuntimeState (Locutus helper dependency)
interface LocutusRuntimeContainer {
  php?: PhpAssoc<PhpInput>
}

interface PhpGlobalProcessLike {
  env?: PhpAssoc<string | undefined>
}

interface PhpGlobalBufferLike {
  from?: (...args: PhpInput[]) => PhpInput
}

interface PhpGlobalKnownEntryMap {
  process: PhpGlobalProcessLike
  Buffer: PhpGlobalBufferLike
}

type GlobalWithLocutus = {
  $locutus?: LocutusRuntimeContainer
  [key: string]: PhpInput
}

const globalContext: GlobalWithLocutus =
  typeof window === 'object' && window !== null ? window : typeof global === 'object' && global !== null ? global : {}

function getPhpGlobalEntry<TKey extends keyof PhpGlobalKnownEntryMap>(
  key: TKey,
): PhpGlobalKnownEntryMap[TKey] | undefined

function getPhpGlobalEntry(key: string): PhpInput | undefined

function getPhpGlobalEntry(key: string): PhpInput | undefined {
  const value = globalContext[key]
  return typeof value === 'undefined' ? undefined : value
}

function getPhpObjectEntry(value: PhpInput, key: string): PhpInput | undefined {
  if ((typeof value !== 'object' && typeof value !== 'function') || value === null) {
    return undefined
  }

  let current: object | null = value
  while (current) {
    const descriptor = Object.getOwnPropertyDescriptor(current, key)
    if (descriptor) {
      if (typeof descriptor.get === 'function') {
        const getterValue = descriptor.get.call(value)
        return typeof getterValue === 'undefined' ? undefined : getterValue
      }
      const directValue = descriptor.value
      return typeof directValue === 'undefined' ? undefined : directValue
    }
    current = Object.getPrototypeOf(current)
  }

  return undefined
}

// php/_helpers/_callbackResolver (Locutus helper dependency)
type CallbackValue = PhpInput

interface CallbackResolverOptions {
  invalidMessage: string
  missingScopeMessage?: (scopeName: string) => string
}

interface ResolvedCallback<TArgs extends PhpCallableArgs = PhpCallableArgs, TResult = CallbackValue> {
  fn: PhpCallable<TArgs, TResult>
  scope: CallbackValue
}

function resolvePhpCallable<TArgs extends PhpCallableArgs = PhpCallableArgs, TResult = CallbackValue>(
  callback: PhpCallableDescriptor<TArgs, TResult>,
  options: CallbackResolverOptions,
): ResolvedCallback<TArgs, TResult> {
  if (isPhpCallable<TArgs, TResult>(callback)) {
    return { fn: callback, scope: null }
  }

  if (typeof callback === 'string') {
    const candidate = getPhpGlobalEntry(callback)
    if (isPhpCallable<TArgs, TResult>(candidate)) {
      return { fn: candidate, scope: null }
    }
    throw new Error(options.invalidMessage)
  }

  if (Array.isArray(callback) && callback.length >= 2) {
    const scopeDescriptor = callback[0]
    const callableDescriptor = callback[1]

    let scope: CallbackValue
    if (typeof scopeDescriptor === 'string') {
      scope = getPhpGlobalEntry(scopeDescriptor)
      if (typeof scope === 'undefined' && options.missingScopeMessage) {
        throw new Error(options.missingScopeMessage(scopeDescriptor))
      }
    } else {
      scope = scopeDescriptor
    }

    if (isPhpCallable<TArgs, TResult>(callableDescriptor)) {
      return { fn: callableDescriptor, scope }
    }

    if (typeof callableDescriptor === 'string' && (isObjectLike(scope) || typeof scope === 'function')) {
      const candidate = getPhpObjectEntry(scope, callableDescriptor)
      if (isPhpCallable<TArgs, TResult>(candidate)) {
        return { fn: candidate, scope }
      }
    }
  }

  throw new Error(options.invalidMessage)
}

// php/funchand/call_user_func_array (Locutus dependency module)
type FunctionValue = PhpRuntimeValue

type FunctionScope = FunctionValue | object

function call_user_func_array<TResult = FunctionValue, TArgs extends PhpCallableArgs = PhpCallableArgs>(
  cb: PhpCallableDescriptor<TArgs, TResult>,
  parameters: [...TArgs],
): TResult {
  //  discuss at: https://locutus.io/php/call_user_func_array/
  // original by: Thiago Mata (https://thiagomata.blog.com)
  //  revised by: Jon Hohle
  // improved by: Brett Zamir (https://brett-zamir.me)
  // improved by: Diplom@t (https://difane.com/)
  // improved by: Brett Zamir (https://brett-zamir.me)
  //      note 1: Callback resolution intentionally avoids eval/new Function for security.
  //   example 1: call_user_func_array('isNaN', ['a'])
  //   returns 1: true
  //   example 2: call_user_func_array('isNaN', [1])
  //   returns 2: false

  let func: PhpCallable<TArgs, TResult> | undefined
  let scope: FunctionScope = null

  try {
    const resolved = resolvePhpCallable<TArgs, TResult>(cb, { invalidMessage: 'invalid' })
    func = resolved.fn
    scope = resolved.scope
  } catch {
    // Fall back to legacy-compatible callback resolution paths below.
  }

  if (!func && typeof cb === 'string') {
    const globalCandidate = getPhpGlobalEntry(cb)
    if (isPhpCallable<TArgs, TResult>(globalCandidate)) {
      func = globalCandidate
    }
  } else if (!func && Array.isArray(cb)) {
    if (typeof cb[0] === 'string') {
      const globalScope = getPhpGlobalEntry(cb[0])
      if (isObjectLike(globalScope) || typeof globalScope === 'function') {
        const method = getPhpObjectEntry(globalScope, String(cb[1]))
        if (isPhpCallable<TArgs, TResult>(method)) {
          func = method
        }
        scope = globalScope
      }
    } else if (isObjectLike(cb[0]) || typeof cb[0] === 'function') {
      const method = getPhpObjectEntry(cb[0], String(cb[1]))
      if (isPhpCallable<TArgs, TResult>(method)) {
        func = method
      }
      scope = cb[0]
    }
  } else if (!func && isPhpCallable<TArgs, TResult>(cb)) {
    func = cb
  }

  if (!func) {
    throw new Error(String(cb) + ' is not a valid function')
  }

  return func.apply(scope, parameters)
}

// php/funchand/call_user_func (target function module)
const callUserFuncArray = call_user_func_array;

type FunctionArg = PhpRuntimeValue

function call_user_func<TResult = FunctionArg, TArgs extends PhpCallableArgs = PhpCallableArgs>(
  cb: PhpCallableDescriptor<TArgs, TResult>,
  ...parameters: TArgs
): TResult {
  //  discuss at: https://locutus.io/php/call_user_func/
  // original by: Brett Zamir (https://brett-zamir.me)
  // improved by: Diplom@t (https://difane.com/)
  // improved by: Brett Zamir (https://brett-zamir.me)
  //      note 1: Depends on call_user_func_array which in turn depends on the `cb` that is passed,
  //      note 1: this function can use `eval`.
  //      note 1: The `eval` input is however checked to only allow valid function names,
  //      note 1: So it should not be unsafer than uses without eval (seeing as you can)
  //      note 1: already pass any function to be executed here.
  //   example 1: call_user_func('isNaN', 'a')
  //   returns 1: true

  return callUserFuncArray<TResult, TArgs>(cb, parameters)
}

// php/_helpers/_phpTypes (Locutus helper dependency)
function isObjectLike(value) {
  return typeof value === 'object' && value !== null
}

function isPhpCallable(value) {
  return typeof value === 'function'
}

// php/_helpers/_phpRuntimeState (Locutus helper dependency)
const globalContext =
  typeof window === 'object' && window !== null ? window : typeof global === 'object' && global !== null ? global : {}

function getPhpGlobalEntry(key) {
  const value = globalContext[key]
  return typeof value === 'undefined' ? undefined : value
}

function getPhpObjectEntry(value, key) {
  if ((typeof value !== 'object' && typeof value !== 'function') || value === null) {
    return undefined
  }

  let current = value
  while (current) {
    const descriptor = Object.getOwnPropertyDescriptor(current, key)
    if (descriptor) {
      if (typeof descriptor.get === 'function') {
        const getterValue = descriptor.get.call(value)
        return typeof getterValue === 'undefined' ? undefined : getterValue
      }
      const directValue = descriptor.value
      return typeof directValue === 'undefined' ? undefined : directValue
    }
    current = Object.getPrototypeOf(current)
  }

  return undefined
}

// php/_helpers/_callbackResolver (Locutus helper dependency)
function resolvePhpCallable(callback, options) {
  if (isPhpCallable(callback)) {
    return { fn: callback, scope: null }
  }

  if (typeof callback === 'string') {
    const candidate = getPhpGlobalEntry(callback)
    if (isPhpCallable(candidate)) {
      return { fn: candidate, scope: null }
    }
    throw new Error(options.invalidMessage)
  }

  if (Array.isArray(callback) && callback.length >= 2) {
    const scopeDescriptor = callback[0]
    const callableDescriptor = callback[1]

    let scope
    if (typeof scopeDescriptor === 'string') {
      scope = getPhpGlobalEntry(scopeDescriptor)
      if (typeof scope === 'undefined' && options.missingScopeMessage) {
        throw new Error(options.missingScopeMessage(scopeDescriptor))
      }
    } else {
      scope = scopeDescriptor
    }

    if (isPhpCallable(callableDescriptor)) {
      return { fn: callableDescriptor, scope }
    }

    if (typeof callableDescriptor === 'string' && (isObjectLike(scope) || typeof scope === 'function')) {
      const candidate = getPhpObjectEntry(scope, callableDescriptor)
      if (isPhpCallable(candidate)) {
        return { fn: candidate, scope }
      }
    }
  }

  throw new Error(options.invalidMessage)
}

// php/funchand/call_user_func_array (Locutus dependency module)
function call_user_func_array(cb, parameters) {
  //  discuss at: https://locutus.io/php/call_user_func_array/
  // original by: Thiago Mata (https://thiagomata.blog.com)
  //  revised by: Jon Hohle
  // improved by: Brett Zamir (https://brett-zamir.me)
  // improved by: Diplom@t (https://difane.com/)
  // improved by: Brett Zamir (https://brett-zamir.me)
  //      note 1: Callback resolution intentionally avoids eval/new Function for security.
  //   example 1: call_user_func_array('isNaN', ['a'])
  //   returns 1: true
  //   example 2: call_user_func_array('isNaN', [1])
  //   returns 2: false

  let func
  let scope = null

  try {
    const resolved = resolvePhpCallable(cb, { invalidMessage: 'invalid' })
    func = resolved.fn
    scope = resolved.scope
  } catch {
    // Fall back to legacy-compatible callback resolution paths below.
  }

  if (!func && typeof cb === 'string') {
    const globalCandidate = getPhpGlobalEntry(cb)
    if (isPhpCallable(globalCandidate)) {
      func = globalCandidate
    }
  } else if (!func && Array.isArray(cb)) {
    if (typeof cb[0] === 'string') {
      const globalScope = getPhpGlobalEntry(cb[0])
      if (isObjectLike(globalScope) || typeof globalScope === 'function') {
        const method = getPhpObjectEntry(globalScope, String(cb[1]))
        if (isPhpCallable(method)) {
          func = method
        }
        scope = globalScope
      }
    } else if (isObjectLike(cb[0]) || typeof cb[0] === 'function') {
      const method = getPhpObjectEntry(cb[0], String(cb[1]))
      if (isPhpCallable(method)) {
        func = method
      }
      scope = cb[0]
    }
  } else if (!func && isPhpCallable(cb)) {
    func = cb
  }

  if (!func) {
    throw new Error(String(cb) + ' is not a valid function')
  }

  return func.apply(scope, parameters)
}

// php/funchand/call_user_func (target function module)
const callUserFuncArray = call_user_func_array

function call_user_func(cb, ...parameters) {
  //  discuss at: https://locutus.io/php/call_user_func/
  // original by: Brett Zamir (https://brett-zamir.me)
  // improved by: Diplom@t (https://difane.com/)
  // improved by: Brett Zamir (https://brett-zamir.me)
  //      note 1: Depends on call_user_func_array which in turn depends on the `cb` that is passed,
  //      note 1: this function can use `eval`.
  //      note 1: The `eval` input is however checked to only allow valid function names,
  //      note 1: So it should not be unsafer than uses without eval (seeing as you can)
  //      note 1: already pass any function to be executed here.
  //   example 1: call_user_func('isNaN', 'a')
  //   returns 1: true

  return callUserFuncArray(cb, parameters)
}

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