Register the directory where the class files are located, so that autoload can get them.<\/p>\n\n\n\n
Registration is done with the composer's configuration file, composer.json.<\/p>\n\n\n\n
Register autoload to composer.json<\/div>
{\n \"name\": \"user-test\/php-test-autoload\",\n \"authors\": [\n {\n \"name\": \"user-test\",\n \"email\": \"user-test@gmail.com\"\n }\n ],\n \"require\": {},\n \"autoload\": {\n \"psr-4\": {\n \"Origin\\\\\": \"src\/\"\n }\n }\n}<\/code><\/pre>\n\n\n\nIn autoload{}, the class files in the src directory are registered to begin with 'Origin'.<\/p>\n\n\n\n
In psr4, namespace names must start with a capital letter, so 'src' cannot be used.<\/p>\n\n\n\n
Here, when loading the class, we convert 'src' to 'Origin' to match the namespace.<\/p>\n\n\n\n
\n
Match directory configuration and namespace configuration<\/p>\n<\/div>\n\n\n\n
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The composer.json will be updated when you install the package using composer.<\/p>\n\n\n\n
The class of the package is automatically added to the autoload{}. You do not have to work by yourself.<\/p>\n\n\n\n
This time, I edited it directly in my own program and not in the composer package.<\/p>\n<\/div>\n\n\n\n
\n
If you edit composer.json directly, you must execute the following command.<\/p>\n\n\n\n
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composer validate<\/p>\n<\/div>\n\n\n\n
This is the composer.json syntax check command. If you get an error, your edits are wrong.<\/p>\n\n\n\n
Be careful, as you will not be able to use composer commands.<\/p>\n<\/div>\n\n\n\n
Updating the autoload map file<\/h3>\n\n\n\n Update autoload.<\/p>\n\n\n\n
autoload update command<\/div>
composer update<\/code><\/pre>\n\n\n\nThis updates the settings in composer.json to be precise. Since we added autoload{}, this will also update autoload.<\/p>\n\n\n\n
The mechanism of autoload is simple.<\/p>\n\n\n\n
\n
composer install<\/p>\n\n\n\n
composer update<\/p>\n\n\n\n
composer require<\/p>\n<\/div>\n\n\n\n
Execute this command to create and update the map file.<\/p>\n\n\n\n
The contents of the map file is just an array, in which the classes and namespaces are defined.<\/p>\n\n\n\n
Autoload doesn't load a class, it just refers to the defined class.<\/p>\n\n\n\n
\n
...\u2500 php-test-autoload\n \u2514\u2500 vendor\n \u2514\u2500 composer\n \u251c\u2500 autoload_classmap.php\n \u251c\u2500 autoload_namespaces.php\n \u251c\u2500 autoload_psr4.php\n \u251c\u2500 autoload_static.php\n \u2514\u2500 installed.php<\/code><\/pre>\n<\/div>\n\n\n\nYou saw earlier, these files of autoload are map files.<\/p>\n\n\n\n
The autoload registration of psr4 in composer.json will be updated like this<\/p>\n\n\n\n
autoload_psr4.php<\/div>
<?php\n\n\/\/ autoload_psr4.php @generated by Composer\n\n$vendorDir = dirname(dirname(__FILE__));\n$baseDir = dirname($vendorDir);\n\nreturn array(\n 'Origin\\\\' => array($baseDir . '\/src'),\n);<\/code><\/pre>\n\n\n\nThe conversion 'src' -> 'Origin' is registered in the map.<\/p>\n\n\n\n
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When the composer command updates the composer.json file, it expands the contents defined in autoload{} to the autoload map file.<\/p>\n<\/div>\n\n\n\n
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vendor\/autoload.php is a summary of all the map files. So only 'require'.<\/p>\n<\/div>\n\n\n\n
Let's run the program!<\/h3>\n\n\n\n The autoload sample program is now complete. Let's run it.<\/p>\n\n\n\n
Execution Confirmation<\/div>
php src\/main.php\nnew instance TestClass1\nnew instance TestClass2\nnew instance TestClass3<\/code><\/pre>\n\n\n\nIf you run it in the home of the project and get the same result, the usage of autoload is OK.<\/p>\n\n\n\n
Updating the autoload map<\/h2>\n\n\n\n Earlier, we updated the map file with this command.<\/p>\n\n\n\n
<\/div>
composer update<\/code><\/pre>\n\n\n\nBut this command is for updating the composer.json file, not for updating the map.<\/p>\n\n\n\n
For example, when you add the source code, the class is not registered in the map.<\/p>\n\n\n\n
The composer.json has not been edited, so the \"composer update\" command will not work either.<\/p>\n\n\n\n
In that case, use the following command.<\/p>\n\n\n\n
The autoload map update command<\/div>
composer dump-autoload<\/code><\/pre>\n\n\n\nThis reconstructs the autoload map only<\/span>.<\/p>\n\n\n\n\n
Class not Found<\/p>\n<\/div>\n\n\n\n
Let's do this once it occurs.<\/p>\n\n\n\n
Surprisingly, sometimes it is not a bug in the program, but just the map is not updated.<\/p>\n\n\n\n
Be careful when using 'dump-autoload -o'<\/h3>\n\n\n\n Autoload has a map optimization feature called 'Autoloader Optimization' for fast loading.<\/p>\n\n\n\n
Speeding up autoload<\/div>
composer dump-autoload -o<\/code><\/pre>\n\n\n\n'-o' option. But be careful.<\/p>\n\n\n\n
With this option, the rules of psr-4 will be ignored when rebuilding the class map.<\/p>\n\n\n\n
Class files with namespace and directory configurations that do not conform to psr-4 will also be registered in the class map.<\/p>\n\n\n\n
You may suddenly get a lot of \"Class not Found\".<\/p>\n\n\n\n
This happens when you are updating a map with options and one time you update it without options. Surprisingly, this pattern is very common.<\/p>\n\n\n\n
It should be noted that this is a common occurrence in Laravel.<\/p>\n\n\n\nDevelopment Environment<\/td> No options<\/td><\/tr> Production Environment<\/td> Optional<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nIt is better to use this usage.<\/p>\n\n\n\n
Non-class can also autoload<\/h2>\n\n\n\n Autoload can autoloading even outside of classes.<\/p>\n\n\n\n
\n
interface<\/li> function<\/li> const<\/li><\/ul>\n<\/div>\n\n\n\nA variety of autoload<\/div>
<?php\nrequire vendor\/autoload.php;\n\nuse My\\Full\\ClassName as ClassName;\nuse My\\Full\\InterfaceName as IFName;\n\nclass Test extends ClassName implements IFName {\n \/\/ ...\n}\n\u00a0\n\/\/ >= PHP 5.6\nuse function My\\Full\\functionName as func;\n\n$ret = func();\n\u00a0\n\/\/ >= PHP 5.6\nuse const My\\Full\\CONSTANT CONST_A;\n\n$val = CONST_A;<\/code><\/pre>\n\n\n\nHowever, function and const are only supported by PHP version 5.6 or later.<\/p>\n\n\n\n
Laravel is already in<\/h2>\n\n\n\n The PHP web framework Laravel includes a composer.<\/p>\n\n\n\n
There is also composer.json and the autoload package in vendor\/composer.<\/p>\n\n\n\n
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require vendor\/autoload.php<\/p>\n<\/div>\n\n\n\n
This is also not necessary. It is already implemented in public\/index.php.<\/p>\n\n\n\n
Summary of autoload<\/h2>\n\n\n\n\n
Write \"require vendor\/autoload.php\" only once in the source code.<\/li> The use operator allows classes, interfaces, functions and const to be autoloaded.<\/li> Write the configuration in the composer.json file.<\/li><\/ul>\n<\/div>\n\n\n\nThis is the only basic usage of autoload.<\/p>\n\n\n\n
I'd like to say \"this is the end\", but I'll continue with the advanced part.<\/p>\n\n\n\n
Didn't you also describe the psr4 used in composer.json's autoload{} ?<\/p>\n\n\n\n
Other methods of specification are also described.<\/p>\n\n\n\n