PHPue 0.0.3 · updated 2026-10-12 View as markdown

Common mistakes and verified fixes

Each row was compiled with PHPue 0.0.3's convert_pvue_file(). Many of these do not throw an error: the page silently renders the wrong thing. When something looks wrong, read the compiled PHP (?compile=views/page.pvue in dev, or convert_pvue_file() from the CLI).

Template output

You write	What happens	Fix
`{{ $user.name }}`	PHP concatenation: wrong output and warnings	`{{ $user['name'] }}` or `{{ $user->name }}`
`{{ $tags }}` (array)	`htmlspecialchars()` TypeError	`{{ implode(', ', $tags) }}`
`{{ !$x }}`, `{{ (int)$x }}`, `{{ 'text' }}`	printed literally	`{{ $x ? '' : 'no' }}`, `{{ intval($x) }}`, `<?= ... ?>`
`{{ total() }}` meant for Alpine	compiled as a PHP call: `Call to undefined function total()`	`x-text="total()"`
`class="x" {{ $on ? 'aria-current="page"' : '' }}`	quotes escaped: `aria-current="page"`	`aria-current="{{ $on ? 'page' : 'false' }}"` or `<?= ... ?>`
`p-else`, `p-show`, `p-model`	not directives; left as dead attributes	negated `p-if`, raw PHP, `value="{{ $x }}"`
`p-if` element without its closing tag	only the opening tag is wrapped; content always renders	close the element
`p-for="item of $items"`	not converted (`data-phpue-invalid-p-for`)	`p-for="$item in $items"`
Literal `{{ $x }}` in documentation text	gets compiled	`{{ $x }}`

Blocks and files

You write	What happens	Fix
A closing script tag inside a PHP string or comment in `<script>`	the PHP block ends there; the rest is dropped or a parse error	`'</scr' . 'ipt>'`
`const s = '<template>'` in an inline `<script>` inside the template	counted as a nested template; the template swallows the rest of the file	`'<tem' + 'plate>'`, or move the JS to `<cscript>`
JavaScript in `<script>` (Vue habit)	PHP parse error: `<script>` is PHP	browser JS goes in `<cscript>`
`<html>`, `<head>`, `<body>` in a `.pvue`	duplicated document structure	PHPue prints them; use `<header>` for head tags
Editing `.pvue` while `.dist/` exists	no effect; the compiled copy is served	delete `.dist/` or rebuild

Components

You write	What happens	Fix
`<Card title="x"/>`, `<Card>slot</Card>`	not replaced: the raw tag is printed, nothing renders	set `$cardTitle` before `<Card/>`; components inherit scope
`function helper() {}` in a component used twice or in a loop	`Cannot redeclare helper()`	move to `backend/` or use a closure
`const x = ...` at the top level of a reused component's `<cscript>`	JS `Identifier 'x' has already been declared`	IIFE, `var`, or move to the view/App cscript
`<Card/>` without `@require`	renders nothing useful	`@require Card 'components/Card.pvue';`
Component uses `$title`, parent also uses `$title`	the component overwrites the parent's variable	specific names (`$cardTitle`)

Routing, scope and headers

You write	What happens	Fix
`#require Home 'views/index.pvue';`	ignored (PHP `#` comment)	`#require 'views/index.pvue';`
`views/blog/post.pvue`, URL `/blog/post`	404	flat views + query strings
`?page=2` for pagination	overwritten by the route slug	`?p=2`
App variable used in a view	undefined	backend singleton, `$_SESSION`, `define()`
`<title>{{ $postTitle }}</title>` in a view header	prints the literal text `$postTitle`	dynamic meta from the App header (MetaControl)
`{{ count($x) }}` or `{{ $a ?? '' }}` in the App header	not converted	build the string in the App script, print `{{ $titleTag }}`
`<?= $x ?>` in the App header	printed literally (it is a heredoc)	`{{ $x }}`
Inline `<script>$(function(){...})</script>` in the App header	`$` interpolated by the heredoc	move JS to a file or `<cscript>`
`phpue_set_lang('cy')` in a view	too late, `<html lang>` already printed	App script or `backend/`
`__DIR__ . '/data/x.json'` in a view	breaks after `php index.php build`	`getcwd() . '/data/x.json'`
Variables named `$routing`, `$current_route`, `$b404`, `$input`, `$action`	reset by the compiled preamble	other names

AJAX

You write	What happens	Fix
`return ['ok' => true];` in a handler	empty response	`echo json_encode(['ok' => true]);`
`fetch('', {method: 'POST', body: formData})`	no action found: the full HTML page comes back (200)	send JSON, or a backend endpoint for uploads
Handler uses a variable set in the view script	undefined (handlers run first)	recompute in the handler or use a singleton
`@AJAX('POST')` called with GET (or the reverse)	405	match the method
Client calls a plain (non-`@AJAX`) function by `action`	falls through to the HTML page	mark it `@AJAX('POST')`
Two handlers with the same name in different views	fatal redeclare	unique names app-wide

cscript

You write	What happens	Fix
`const name = "{{ $name }}";`	`""Ada""`: JS syntax error	`const name = {{ $name }};`
`const n = {{ count($items) }};`	not converted: broken JS	`const n = <?= json_encode(count($items)) ?>;`

Sessions and caching

You write	What happens	Fix
Writing `$_SESSION` in a view with `PHPUE_SESSION = 'lazy'`	lost for first-time visitors (no session yet)	`phpue_session(true)` before the write
`session_start()` anywhere in the App script text (even a comment)	PHPue's session handling switches off	remove it; use `phpue_session()`
Expecting nginx/CDN caching with default settings	every response sets a cookie and `no-store`	`PHPUE_SESSION = 'lazy'`
A backend file that `return`s an array, loaded with `require_once`	second load returns `true`, not the array	folder with `autoload.php`, or `require`