MAPG-89 add classes that can link views into one PHP

src/View/Parser.php

@@ -0,0 +1,128 @@
+<?php namespace MapGuesser\View;
+
+class Parser
+{
+    private string $file;
+
+    public function __construct(string $file)
+    {
+        $this->file = $file;
+    }
+
+    public function parse(): ParsedFragment
+    {
+
+        $sectionOpen = null;
+        $extraOpen = false;
+
+        $extends = null;
+        $sections = [];
+        $extra = ['', ''];
+
+        $fileHandle = fopen($this->file, 'r');
+        if (!$fileHandle) {
+            throw new \Exception('Cannot open file ' . $this->file);
+        }
+
+        $lineNumber = 0;
+        while (($line = fgets($fileHandle)) !== false) {
+            ++$lineNumber;
+
+            if (($extendsMatched = $this->matchExtends($line)) !== null) {
+                if ($extends !== null) {
+                    throw new \Exception('Error in file ' . $this->file . ' in line ' . $lineNumber . ' - There is already an \'@extends\' declared.');
+                }
+
+                $extends = $extendsMatched;
+
+                continue;
+            }
+
+            if (($sectionMatched = $this->matchSection($line)) !== null) {
+                if ($extends === null) {
+                    throw new \Exception('Error in file ' . $this->file . ' in line ' . $lineNumber . ' - \'@section\' has no meaning if view extends nothing.');
+                }
+                if ($sectionOpen !== null) {
+                    throw new \Exception('Parse error in file ' . $this->file . ' in line ' . $lineNumber . ' - A \'@section\' is already open (no \'@endsection\' found).');
+                }
+
+                $sectionOpen = $sectionMatched;
+                $sections[$sectionOpen] = '';
+
+                continue;
+            }
+
+            if ($this->matchEndSection($line)) {
+                if ($sectionOpen === null) {
+                    throw new \Exception('Parse error in file ' . $this->file . ' in line ' . $lineNumber . ' - Cannot end section until no \'@section\' is open.');
+                }
+
+                $sectionOpen = null;
+            }
+
+            if ($this->matchExtra($line)) {
+                if ($extraOpen) {
+                    throw new \Exception('Parse error in file ' . $this->file . ' in line ' . $lineNumber . ' - An \'@extra\' is already open (no \'@endextra\' found).');
+                }
+
+                $extraOpen = true;
+
+                continue;
+            }
+
+            if ($this->matchEndExtra($line)) {
+                if (!$extraOpen) {
+                    throw new \Exception('Parse error in file ' . $this->file . ' in line ' . $lineNumber . ' - Cannot end extra until no \'@extra\' is open.');
+                }
+
+                $extraOpen = false;
+            }
+
+            if ($sectionOpen !== null) {
+                $sections[$sectionOpen] .= $line;
+            }
+
+            if ($extraOpen) {
+                $offset = $extends === null ? 0 : 1;
+                $extra[$offset] .= $line;
+            }
+        }
+
+        fclose($fileHandle);
+
+        return new ParsedFragment($extends, $sections, $extra);
+    }
+
+    private function matchExtends(string $line): ?string
+    {
+        if (preg_match('/^\s*@extends\(\'([\w\/]+)\'\)\s*$/', $line, $matches)) {
+            return $matches[1];
+        }
+
+        return null;
+    }
+
+    private function matchSection(string $line): ?string
+    {
+        if (preg_match('/^\s*@section\(\'(\w+)\'\)\s*$/', $line, $matches)) {
+            return $matches[1];
+        }
+
+        return null;
+    }
+
+    private function matchEndSection(string $line): bool
+    {
+        return preg_match('/^\s*@endsection(?:\(\))?\s*$/', $line);
+    }
+
+    private function matchExtra(string $line): bool
+    {
+        return preg_match('/^\s*@extra(?:\(\))?\s*$/', $line);
+    }
+
+    private function matchEndExtra(string $line): bool
+    {
+        return preg_match('/^\s*@endextra(?:\(\))?\s*$/', $line);
+    }
+}