feat(log): render multi-line log messages with preserved whitespace, print_r() dumps as a tree, and var_export() values highlighted.

.github/linters/.editorconfig-checker.json

@@ -15,6 +15,7 @@
         "^code_coverage/",
         "^composer\\.lock$",
         "^runtime/",
+        "^tests/Support/PrintR/server-request\\.txt$",
         "^tests/runtime/",
         "^vendor/",
         "phpstan-baseline\\.neon$",

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## 0.1.2 Under development
 
+- feat(log): render multi-line log messages with preserved whitespace, `print_r()` dumps as a tree, and `var_export()` values highlighted.
+
 ## 0.1.1 October 28, 2026
 
 - fix(event): skip `InstrumentationGuard` trace frames on Windows by joining the skip path with `DIRECTORY_SEPARATOR`.

composer.json

@@ -23,6 +23,7 @@
         "ext-ctype": "*",
         "ext-intl": "*",
         "ext-mbstring": "*",
+        "ext-tokenizer": "*",
         "ui-awesome/html": "^0.6",
         "ui-awesome/html-core-component": "^0.4",
         "ui-awesome/html-helper": "^0.7",

resources/src/styles/main.css

@@ -3471,6 +3471,138 @@
     }
   }
 
+  /**
+   * Multi-line log message: the text keeps its line breaks and indentation
+   * but reads like the single-line messages around it.
+   */
+  .yii-debug-log-text {
+    margin: 0;
+    padding: 0;
+    background: none;
+    color: inherit;
+    font-family: var(--yii-debug-font-mono);
+    font-size: var(--yii-debug-fs-xs);
+    line-height: 1.6;
+    font-variant-ligatures: none;
+    white-space: pre-wrap;
+    overflow-wrap: anywhere;
+  }
+
+  /**
+   * print_r() dump tree: an open root block over collapsed nested blocks,
+   * sharing the tokens of the queue payload tree. A highlighted
+   * var_export() message shares the box.
+   */
+  .yii-debug-log-dump,
+  .yii-debug-log-export pre {
+    padding: var(--yii-debug-space-2) var(--yii-debug-space-3);
+    border-radius: var(--yii-debug-radius-sm);
+    background: color-mix(
+      in srgb,
+      var(--yii-debug-panel-text),
+      transparent 96%
+    );
+    font-family: var(--yii-debug-font-mono);
+    font-size: var(--yii-debug-fs-xs);
+    line-height: 1.6;
+    font-variant-ligatures: none;
+  }
+
+  .yii-debug-log-dump-summary,
+  .yii-debug-log-dump-row {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: baseline;
+    gap: 2px var(--yii-debug-space-2);
+    padding-left: calc(1ch + var(--yii-debug-space-2));
+  }
+
+  /* The marker sits in the padding so it never wraps apart from the label. */
+  .yii-debug-log-dump-summary {
+    position: relative;
+    cursor: pointer;
+    list-style: none;
+
+    &::-webkit-details-marker {
+      display: none;
+    }
+
+    &::before {
+      position: absolute;
+      left: 0;
+      content: "\25B8";
+      color: var(--yii-debug-panel-muted);
+    }
+  }
+
+  :is(.yii-debug-log-dump, .yii-debug-log-dump-node)[open]
+    > .yii-debug-log-dump-summary::before {
+    transform: rotate(90deg);
+  }
+
+  .yii-debug-log-dump-entries {
+    margin-left: 0.5ch;
+    padding-left: calc(0.5ch + var(--yii-debug-space-2));
+    border-left: 1px dashed
+      color-mix(in srgb, var(--yii-debug-panel-text), transparent 80%);
+  }
+
+  .yii-debug-log-dump-key {
+    font-weight: 700;
+    white-space: pre-wrap;
+    overflow-wrap: anywhere;
+
+    &::after {
+      content: ":";
+      color: var(--yii-debug-panel-muted);
+    }
+  }
+
+  .yii-debug-log-dump-value {
+    flex: 1 1 16ch;
+    min-width: 0;
+    white-space: pre-wrap;
+    overflow-wrap: anywhere;
+  }
+
+  .yii-debug-log-dump-kind,
+  .yii-debug-log-dump-visibility,
+  .yii-debug-log-dump-recursion {
+    padding: 0 6px;
+    border-radius: 3px;
+    background: color-mix(
+      in srgb,
+      var(--yii-debug-panel-text),
+      transparent 92%
+    );
+    letter-spacing: 0.05em;
+  }
+
+  .yii-debug-log-dump-kind,
+  .yii-debug-log-dump-recursion {
+    text-transform: uppercase;
+  }
+
+  .yii-debug-log-dump-kind,
+  .yii-debug-log-dump-visibility,
+  .yii-debug-log-dump-count,
+  .yii-debug-log-dump-prefix,
+  .yii-debug-log-dump-empty {
+    color: var(--yii-debug-panel-muted);
+  }
+
+  .yii-debug-log-dump-visibility,
+  .yii-debug-log-dump-empty {
+    font-style: italic;
+    cursor: help;
+  }
+
+  .yii-debug-log-dump-recursion {
+    background: color-mix(in srgb, var(--yii-debug-warning), transparent 86%);
+    color: var(--yii-debug-warning);
+    cursor: help;
+  }
+
   /* Inline helper utilities. */
   .yii-debug-muted {
     color: var(--yii-debug-panel-muted);

src/Helper/PhpHighlighter.php

@@ -15,17 +15,39 @@ final class PhpHighlighter
     /**
      * Highlights a value as the PHP expression that would recreate it.
      *
-     * The expression is built here and handed straight to PHP's highlighter, which escapes it, so the result carries no
-     * markup from the captured value.
-     *
-     * The `<pre>` wrapper scrolls horizontally, so it carries `tabindex="0"` to stay reachable by keyboard.
+     * The expression is built here with {@see Dump::export()} and handed to {@see self::highlightCode()}, so the result
+     * carries no markup from the captured value.
      *
      * @param mixed $value JSON-safe value to render.
      *
      * @return string Highlighted markup in a focusable `<pre>`, without the opening tag PHP needs to recognize the
      * snippet.
      */
     public static function highlight(mixed $value): string
+    {
+        return self::highlightCode(Dump::export($value));
+    }
+
+    /**
+     * Highlights PHP source text, such as the `var_export()` output carried by a log message.
+     *
+     * PHP's highlighter escapes the whole source, so markup carried by the text renders as text and never as markup.
+     * The source is only highlighted, never evaluated.
+     *
+     * The `<pre>` wrapper scrolls horizontally, so it carries `tabindex="0"` to stay reachable by keyboard.
+     *
+     * Usage example:
+     * ```php
+     * $html = PhpHighlighter::highlightCode("array (\n  'id' => 7,\n)");
+     * // '<pre tabindex="0"><code style="color: #000000"><span style="color: #007700">array (' . "\n" . '  </span>...'
+     * ```
+     *
+     * @param string $code PHP source of an expression, without the opening tag.
+     *
+     * @return string Highlighted markup in a focusable `<pre>`, without the opening tag PHP needs to recognize the
+     * snippet.
+     */
+    public static function highlightCode(string $code): string
     {
         return (string) preg_replace(
             [
@@ -34,7 +56,7 @@ public static function highlight(mixed $value): string
                 '~^<pre>~',
             ],
             ['$1', '$1', '<pre tabindex="0">'],
-            highlight_string("<?php\n" . Dump::export($value), true),
+            highlight_string("<?php\n" . $code, true),
         );
     }
 }

src/Helper/Text.php

@@ -4,6 +4,8 @@
 
 namespace PHPForge\Debug\Helper;
 
+use UIAwesome\Html\Helper\Encode;
+
 use function is_string;
 use function mb_strtolower;
 use function parse_url;
@@ -16,6 +18,11 @@
  */
 final class Text
 {
+    /**
+     * Line break sequences, `\r\n` first so that it reads as one line break, as the HTML parser reads it.
+     */
+    private const array LINE_BREAKS = ["\r\n", "\r", "\n"];
+
     /**
      * Converts a CamelCase name into a lowercase id with `-` word separators, matching the Yii inflector semantics.
      *
@@ -30,6 +37,51 @@ public static function camel2id(string $name): string
         return mb_strtolower(trim(str_replace('_', '-', $replaced), '-'), 'UTF-8');
     }
 
+    /**
+     * Writes each line break of HTML markup as the `
` character reference, leaving the markup itself unchanged.
+     *
+     * Use it for markup that is already escaped and carries line breaks only in its text, such as
+     * {@see PhpHighlighter::highlightCode()} output; {@see self::preserveLineBreaks()} escapes raw text first. `\r\n`
+     * and a lone `\r` become one line break, as the HTML parser reads them.
+     *
+     * Usage example:
+     * ```php
+     * $html = Text::preserveHtmlLineBreaks("<span>'a\r\nb'</span>");
+     * // "<span>'a&#10;b'</span>"
+     * ```
+     *
+     * @param string $html Escaped HTML markup.
+     *
+     * @return string Markup without raw line breaks.
+     */
+    public static function preserveHtmlLineBreaks(string $html): string
+    {
+        return str_replace(self::LINE_BREAKS, '&#10;', $html);
+    }
+
+    /**
+     * Escapes text for HTML content and writes each of its line breaks as the `&#10;` character reference.
+     *
+     * The UI Awesome block builders other than `<pre>` collapse consecutive line breaks in their rendered output, which
+     * drops the blank lines of a multi-line value rendered inside them; a character reference survives that
+     * normalization and still renders as a line break under `white-space: pre-wrap`. `\r\n` and a lone `\r` become one
+     * line break, as the HTML parser reads them.
+     *
+     * Usage example:
+     * ```php
+     * $html = Pre::tag()->html(Text::preserveLineBreaks("a\n\n<b>"))->render();
+     * // "<pre>\na&#10;&#10;&lt;b&gt;\n</pre>"
+     * ```
+     *
+     * @param string $text Raw text to render.
+     *
+     * @return string Escaped HTML content without raw line breaks.
+     */
+    public static function preserveLineBreaks(string $text): string
+    {
+        return self::preserveHtmlLineBreaks(Encode::content($text));
+    }
+
     /**
      * Strips the authority from a captured URL for display, retaining its path, non-empty query, and fragment.
      *