comparison vendor/phpdocumentor/reflection-docblock/src/DocBlock/DescriptionFactory.php @ 12:7a779792577d

Update Drupal core to v8.4.5 (via Composer)

+<?php
+/**
+ * This file is part of phpDocumentor.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @copyright 2010-2015 Mike van Riel<[e-mail]>
+ * @license   http://www.opensource.org/licenses/mit-license.php MIT
+ * @link      http://phpdoc.org
+ */
+
+namespace phpDocumentor\Reflection\DocBlock;
+
+use phpDocumentor\Reflection\Types\Context as TypeContext;
+
+/**
+ * Creates a new Description object given a body of text.
+ *
+ * Descriptions in phpDocumentor are somewhat complex entities as they can contain one or more tags inside their
+ * body that can be replaced with a readable output. The replacing is done by passing a Formatter object to the
+ * Description object's `render` method.
+ *
+ * In addition to the above does a Description support two types of escape sequences:
+ *
+ * 1. `{@}` to escape the `@` character to prevent it from being interpreted as part of a tag, i.e. `{{@}link}`
+ * 2. `{}` to escape the `}` character, this can be used if you want to use the `}` character in the description
+ *    of an inline tag.
+ *
+ * If a body consists of multiple lines then this factory will also remove any superfluous whitespace at the beginning
+ * of each line while maintaining any indentation that is used. This will prevent formatting parsers from tripping
+ * over unexpected spaces as can be observed with tag descriptions.
+ */
+class DescriptionFactory
+{
+    /** @var TagFactory */
+    private $tagFactory;
+
+    /**
+     * Initializes this factory with the means to construct (inline) tags.
+     *
+     * @param TagFactory $tagFactory
+     */
+    public function __construct(TagFactory $tagFactory)
+    {
+        $this->tagFactory = $tagFactory;
+    }
+
+    /**
+     * Returns the parsed text of this description.
+     *
+     * @param string $contents
+     * @param TypeContext $context
+     *
+     * @return Description
+     */
+    public function create($contents, TypeContext $context = null)
+    {
+        list($text, $tags) = $this->parse($this->lex($contents), $context);
+
+        return new Description($text, $tags);
+    }
+
+    /**
+     * Strips the contents from superfluous whitespace and splits the description into a series of tokens.
+     *
+     * @param string $contents
+     *
+     * @return string[] A series of tokens of which the description text is composed.
+     */
+    private function lex($contents)
+    {
+        $contents = $this->removeSuperfluousStartingWhitespace($contents);
+
+        // performance optimalization; if there is no inline tag, don't bother splitting it up.
+        if (strpos($contents, '{@') === false) {
+            return [$contents];
+        }
+
+        return preg_split(
+            '/\{
+                # "{@}" is not a valid inline tag. This ensures that we do not treat it as one, but treat it literally.
+                (?!@\})
+                # We want to capture the whole tag line, but without the inline tag delimiters.
+                (\@
+                    # Match everything up to the next delimiter.
+                    [^{}]*
+                    # Nested inline tag content should not be captured, or it will appear in the result separately.
+                    (?:
+                        # Match nested inline tags.
+                        (?:
+                            # Because we did not catch the tag delimiters earlier, we must be explicit with them here.
+                            # Notice that this also matches "{}", as a way to later introduce it as an escape sequence.
+                            \{(?1)?\}
+                            |
+                            # Make sure we match hanging "{".
+                            \{
+                        )
+                        # Match content after the nested inline tag.
+                        [^{}]*
+                    )* # If there are more inline tags, match them as well. We use "*" since there may not be any
+                       # nested inline tags.
+                )
+            \}/Sux',
+            $contents,
+            null,
+            PREG_SPLIT_DELIM_CAPTURE
+        );
+    }
+
+    /**
+     * Parses the stream of tokens in to a new set of tokens containing Tags.
+     *
+     * @param string[] $tokens
+     * @param TypeContext $context
+     *
+     * @return string[]|Tag[]
+     */
+    private function parse($tokens, TypeContext $context)
+    {
+        $count = count($tokens);
+        $tagCount = 0;
+        $tags  = [];
+
+        for ($i = 1; $i < $count; $i += 2) {
+            $tags[] = $this->tagFactory->create($tokens[$i], $context);
+            $tokens[$i] = '%' . ++$tagCount . '$s';
+        }
+
+        //In order to allow "literal" inline tags, the otherwise invalid
+        //sequence "{@}" is changed to "@", and "{}" is changed to "}".
+        //"%" is escaped to "%%" because of vsprintf.
+        //See unit tests for examples.
+        for ($i = 0; $i < $count; $i += 2) {
+            $tokens[$i] = str_replace(['{@}', '{}', '%'], ['@', '}', '%%'], $tokens[$i]);
+        }
+
+        return [implode('', $tokens), $tags];
+    }
+
+    /**
+     * Removes the superfluous from a multi-line description.
+     *
+     * When a description has more than one line then it can happen that the second and subsequent lines have an
+     * additional indentation. This is commonly in use with tags like this:
+     *
+     *     {@}since 1.1.0 This is an example
+     *         description where we have an
+     *         indentation in the second and
+     *         subsequent lines.
+     *
+     * If we do not normalize the indentation then we have superfluous whitespace on the second and subsequent
+     * lines and this may cause rendering issues when, for example, using a Markdown converter.
+     *
+     * @param string $contents
+     *
+     * @return string
+     */
+    private function removeSuperfluousStartingWhitespace($contents)
+    {
+        $lines = explode("\n", $contents);
+
+        // if there is only one line then we don't have lines with superfluous whitespace and
+        // can use the contents as-is
+        if (count($lines) <= 1) {
+            return $contents;
+        }
+
+        // determine how many whitespace characters need to be stripped
+        $startingSpaceCount = 9999999;
+        for ($i = 1; $i < count($lines); $i++) {
+            // lines with a no length do not count as they are not indented at all
+            if (strlen(trim($lines[$i])) === 0) {
+                continue;
+            }
+
+            // determine the number of prefixing spaces by checking the difference in line length before and after
+            // an ltrim
+            $startingSpaceCount = min($startingSpaceCount, strlen($lines[$i]) - strlen(ltrim($lines[$i])));
+        }
+
+        // strip the number of spaces from each line
+        if ($startingSpaceCount > 0) {
+            for ($i = 1; $i < count($lines); $i++) {
+                $lines[$i] = substr($lines[$i], $startingSpaceCount);
+            }
+        }
+
+        return implode("\n", $lines);
+    }
+}