提交代码

vendor/phpoffice/phpspreadsheet/docs/topics/architecture.md

@@ -0,0 +1,75 @@
+# Architecture
+
+## Schematical
+
+![01-schematic.png](./images/01-schematic.png "Basic Architecture Schematic")
+
+## AutoLoader
+
+PhpSpreadsheet relies on Composer autoloader. So before working with
+PhpSpreadsheet in standalone, be sure to run `composer install`. Or add it to a
+pre-existing project with `composer require phpoffice/phpspreadsheet`.
+
+## Spreadsheet in memory
+
+PhpSpreadsheet's architecture is built in a way that it can serve as an
+in-memory spreadsheet. This means that, if one would want to create a
+web based view of a spreadsheet which communicates with PhpSpreadsheet's
+object model, he would only have to write the front-end code.
+
+Just like desktop spreadsheet software, PhpSpreadsheet represents a
+spreadsheet containing one or more worksheets, which contain cells with
+data, formulas, images, ...
+
+## Readers and writers
+
+On its own, the `Spreadsheet` class does not provide the functionality
+to read from or write to a persisted spreadsheet (on disk or in a
+database). To provide that functionality, readers and writers can be
+used.
+
+By default, the PhpSpreadsheet package provides some readers and
+writers, including one for the Open XML spreadsheet format (a.k.a. Excel
+2007 file format). You are not limited to the default readers and
+writers, as you are free to implement the
+`\PhpOffice\PhpSpreadsheet\Reader\IReader` and
+`\PhpOffice\PhpSpreadsheet\Writer\IWriter` interface in a custom class.
+
+![02-readers-writers.png](./images/02-readers-writers.png "Readers/Writers")
+
+## Fluent interfaces
+
+PhpSpreadsheet supports fluent interfaces in most locations. This means
+that you can easily "chain" calls to specific methods without requiring
+a new PHP statement. For example, take the following code:
+
+``` php
+$spreadsheet->getProperties()->setCreator("Maarten Balliauw");
+$spreadsheet->getProperties()->setLastModifiedBy("Maarten Balliauw");
+$spreadsheet->getProperties()->setTitle("Office 2007 XLSX Test Document");
+$spreadsheet->getProperties()->setSubject("Office 2007 XLSX Test Document");
+$spreadsheet->getProperties()->setDescription("Test document for Office 2007 XLSX, generated using PHP classes.");
+$spreadsheet->getProperties()->setKeywords("office 2007 openxml php");
+$spreadsheet->getProperties()->setCategory("Test result file");
+```
+
+This can be rewritten as:
+
+``` php
+$spreadsheet->getProperties()
+    ->setCreator("Maarten Balliauw")
+    ->setLastModifiedBy("Maarten Balliauw")
+    ->setTitle("Office 2007 XLSX Test Document")
+    ->setSubject("Office 2007 XLSX Test Document")
+    ->setDescription("Test document for Office 2007 XLSX, generated using PHP classes.")
+    ->setKeywords("office 2007 openxml php")
+    ->setCategory("Test result file");
+```
+
+> **Using fluent interfaces is not required** Fluent interfaces have
+> been implemented to provide a convenient programming API. Use of them
+> is not required, but can make your code easier to read and maintain.
+> It can also improve performance, as you are reducing the overall
+> number of calls to PhpSpreadsheet methods: in the above example, the
+> `getProperties()` method is being called only once rather than 7 times
+> in the non-fluent version.