mirror of
https://github.com/codeigniter4/CodeIgniter4.git
synced 2025-02-20 11:44:28 +08:00
452 lines
21 KiB
HTML
452 lines
21 KiB
HTML
|
|
|
|
<!DOCTYPE html>
|
|
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
|
|
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
|
|
<head>
|
|
<meta charset="utf-8">
|
|
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
|
|
<title>Services — CodeIgniter4 4.0.0-beta.1 documentation</title>
|
|
|
|
|
|
|
|
|
|
<link rel="shortcut icon" href="../_static/ci-icon.ico"/>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<link rel="stylesheet" href="../_static/css/citheme.css" type="text/css" />
|
|
|
|
|
|
|
|
|
|
|
|
<link rel="top" title="CodeIgniter4 4.0.0-beta.1 documentation" href="../index.html"/>
|
|
<link rel="up" title="CodeIgniter4 Overview" href="index.html"/>
|
|
<link rel="next" title="Working With HTTP Requests" href="http.html"/>
|
|
<link rel="prev" title="Autoloading Files" href="autoloader.html"/>
|
|
|
|
|
|
<script src="../_static/js/modernizr.min.js"></script>
|
|
|
|
</head>
|
|
|
|
<body class="wy-body-for-nav" role="document">
|
|
|
|
|
|
<div class="wy-grid-for-nav">
|
|
|
|
|
|
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
|
|
<div class="wy-side-scroll">
|
|
<div class="wy-side-nav-search">
|
|
|
|
|
|
|
|
<a href="../index.html" class="icon icon-home"> CodeIgniter4
|
|
|
|
|
|
|
|
</a>
|
|
|
|
|
|
|
|
|
|
<div role="search">
|
|
<form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
|
|
<input type="text" name="q" placeholder="Search docs" />
|
|
<input type="hidden" name="check_keywords" value="yes" />
|
|
<input type="hidden" name="area" value="default" />
|
|
</form>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../intro/index.html">Welcome to CodeIgniter4</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Tutorial</a></li>
|
|
</ul>
|
|
<ul class="current">
|
|
<li class="toctree-l1 current"><a class="reference internal" href="index.html">CodeIgniter4 Overview</a><ul class="current">
|
|
<li class="toctree-l2"><a class="reference internal" href="structure.html">Application Structure</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="mvc.html">Models, Views, and Controllers</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="autoloader.html">Autoloading Files</a></li>
|
|
<li class="toctree-l2 current"><a class="current reference internal" href="#">Services</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="http.html">Working With HTTP Requests</a></li>
|
|
<li class="toctree-l2"><a class="reference internal" href="security.html">Security Guidelines</a></li>
|
|
</ul>
|
|
</li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../general/index.html">General Topics</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../incoming/index.html">Controllers and Routing</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../outgoing/index.html">Building Responses</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../database/index.html">Working With Databases</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../models/index.html">Modeling Data</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../dbmgmt/index.html">Managing Databases</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Library Reference</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../testing/index.html">Testing</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../cli/index.html">Command Line Usage</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../extending/index.html">Extending CodeIgniter</a></li>
|
|
</ul>
|
|
<ul>
|
|
<li class="toctree-l1"><a class="reference internal" href="../license.html">The MIT License (MIT)</a></li>
|
|
<li class="toctree-l1"><a class="reference internal" href="../changelogs/index.html">Change Logs</a></li>
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
</div>
|
|
</nav>
|
|
|
|
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
|
|
|
|
|
|
<nav class="wy-nav-top" role="navigation" aria-label="top navigation">
|
|
|
|
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
|
|
<a href="../index.html">CodeIgniter4</a>
|
|
|
|
</nav>
|
|
|
|
|
|
|
|
<div class="wy-nav-content">
|
|
<div class="rst-content">
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<div role="navigation" aria-label="breadcrumbs navigation">
|
|
|
|
<ul class="wy-breadcrumbs">
|
|
|
|
<li><a href="../index.html">Docs</a> »</li>
|
|
|
|
<li><a href="index.html">CodeIgniter4 Overview</a> »</li>
|
|
|
|
<li>Services</li>
|
|
|
|
|
|
<li class="wy-breadcrumbs-aside">
|
|
|
|
|
|
|
|
</li>
|
|
|
|
</ul>
|
|
|
|
|
|
<hr/>
|
|
</div>
|
|
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
|
|
<div itemprop="articleBody">
|
|
|
|
<div class="section" id="services">
|
|
<h1>Services<a class="headerlink" href="#services" title="Permalink to this headline">¶</a></h1>
|
|
<div class="contents local topic" id="contents">
|
|
<ul class="simple">
|
|
<li><a class="reference internal" href="#introduction" id="id1">Introduction</a><ul>
|
|
<li><a class="reference internal" href="#convenience-functions" id="id2">Convenience Functions</a></li>
|
|
</ul>
|
|
</li>
|
|
<li><a class="reference internal" href="#defining-services" id="id3">Defining Services</a><ul>
|
|
<li><a class="reference internal" href="#allowing-parameters" id="id4">Allowing Parameters</a></li>
|
|
<li><a class="reference internal" href="#shared-classes" id="id5">Shared Classes</a></li>
|
|
<li><a class="reference internal" href="#service-discovery" id="id6">Service Discovery</a></li>
|
|
</ul>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="section" id="introduction">
|
|
<h2><a class="toc-backref" href="#id1">Introduction</a><a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2>
|
|
<p>All of the classes within CodeIgniter are provided as “services”. This simply means that, instead
|
|
of hard-coding a class name to load, the classes to call are defined within a very simple
|
|
configuration file. This file acts as a type of factory to create new instances of the required class.</p>
|
|
<p>A quick example will probably make things clearer, so imagine that you need to pull in an instance
|
|
of the Timer class. The simplest method would simply be to create a new instance of that class:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$timer</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">\CodeIgniter\Debug\Timer</span><span class="p">();</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>And this works great. Until you decide that you want to use a different timer class in its place.
|
|
Maybe this one has some advanced reporting the default timer does not provide. In order to do this,
|
|
you now have to locate all of the locations in your application that you have used the timer class.
|
|
Since you might have left them in place to keep a performance log of your application constantly
|
|
running, this might be a time-consuming and error-prone way to handle this. That’s where services
|
|
come in handy.</p>
|
|
<p>Instead of creating the instance ourself, we let a central class create an instance of the
|
|
class for us. This class is kept very simple. It only contains a method for each class that we want
|
|
to use as a service. The method typically returns a shared instance of that class, passing any dependencies
|
|
it might have into it. Then, we would replace our timer creation code with code that calls this new class:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$timer</span> <span class="o">=</span> <span class="nx">\Config\Services</span><span class="o">::</span><span class="na">timer</span><span class="p">();</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>When you need to change the implementation used, you can modify the services configuration file, and
|
|
the change happens automatically throughout your application without you having to do anything. Now
|
|
you just need to take advantage of any new functionality and you’re good to go. Very simple and
|
|
error-resistant.</p>
|
|
<div class="admonition note">
|
|
<p class="first admonition-title">Note</p>
|
|
<p class="last">It is recommended to only create services within controllers. Other files, like models and libraries should have the dependencies either passed into the constructor or through a setter method.</p>
|
|
</div>
|
|
<div class="section" id="convenience-functions">
|
|
<h3><a class="toc-backref" href="#id2">Convenience Functions</a><a class="headerlink" href="#convenience-functions" title="Permalink to this headline">¶</a></h3>
|
|
<p>Two functions have been provided for getting a service. These functions are always available.</p>
|
|
<p>The first is <code class="docutils literal"><span class="pre">service()</span></code> which returns a new instance of the requested service. The only
|
|
required parameter is the service name. This is the same as the method name within the Services
|
|
file always returns a SHARED instance of the class, so calling the function multiple times should
|
|
always return the same instance:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$logger</span> <span class="o">=</span> <span class="nx">service</span><span class="p">(</span><span class="s1">'logger'</span><span class="p">);</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>If the creation method requires additional parameters, they can be passed after the service name:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$renderer</span> <span class="o">=</span> <span class="nx">service</span><span class="p">(</span><span class="s1">'renderer'</span><span class="p">,</span> <span class="nx">APPPATH</span><span class="o">.</span><span class="s1">'views/'</span><span class="p">);</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>The second function, <code class="docutils literal"><span class="pre">single_service()</span></code> works just like <code class="docutils literal"><span class="pre">service()</span></code> but returns a new instance of
|
|
the class:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$logger</span> <span class="o">=</span> <span class="nx">single_service</span><span class="p">(</span><span class="s1">'logger'</span><span class="p">);</span>
|
|
</pre></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="section" id="defining-services">
|
|
<h2><a class="toc-backref" href="#id3">Defining Services</a><a class="headerlink" href="#defining-services" title="Permalink to this headline">¶</a></h2>
|
|
<p>To make services work well, you have to be able to rely on each class having a constant API, or
|
|
<a class="reference external" href="http://php.net/manual/en/language.oop5.interfaces.php">interface</a>, to use. Almost all of
|
|
CodeIgniter’s classes provide an interface that they adhere to. When you want to extend or replace
|
|
core classes, you only need to ensure you meet the requirements of the interface and you know that
|
|
the classes are compatible.</p>
|
|
<p>For example, the <code class="docutils literal"><span class="pre">RouterCollection</span></code> class implements the <code class="docutils literal"><span class="pre">RouterCollectionInterface</span></code>. When you
|
|
want to create a replacement that provides a different way to create routes, you just need to
|
|
create a new class that implements the <code class="docutils literal"><span class="pre">RouterCollectionInterface</span></code>:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">MyRouter</span> <span class="k">implements</span> <span class="nx">\CodeIgniter\Router\RouteCollectionInterface</span>
|
|
<span class="p">{</span>
|
|
<span class="c1">// Implement required methods here.</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>Finally, modify <strong>/app/Config/Services.php</strong> to create a new instance of <code class="docutils literal"><span class="pre">MyRouter</span></code>
|
|
instead of <code class="docutils literal"><span class="pre">CodeIgniter\Router\RouterCollection</span></code>:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">public</span> <span class="k">static</span> <span class="k">function</span> <span class="nf">routes</span><span class="p">()</span>
|
|
<span class="p">{</span>
|
|
<span class="k">return</span> <span class="k">new</span> <span class="nx">\App\Router\MyRouter</span><span class="p">();</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
<div class="section" id="allowing-parameters">
|
|
<h3><a class="toc-backref" href="#id4">Allowing Parameters</a><a class="headerlink" href="#allowing-parameters" title="Permalink to this headline">¶</a></h3>
|
|
<p>In some instances, you will want the option to pass a setting to the class during instantiation.
|
|
Since the services file is a very simple class, it is easy to make this work.</p>
|
|
<p>A good example is the <code class="docutils literal"><span class="pre">renderer</span></code> service. By default, we want this class to be able
|
|
to find the views at <code class="docutils literal"><span class="pre">APPPATH.views/</span></code>. We want the developer to have the option of
|
|
changing that path, though, if their needs require it. So the class accepts the <code class="docutils literal"><span class="pre">$viewPath</span></code>
|
|
as a constructor parameter. The service method looks like this:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">public</span> <span class="k">static</span> <span class="k">function</span> <span class="nf">renderer</span><span class="p">(</span><span class="nv">$viewPath</span><span class="o">=</span><span class="nx">APPPATH</span><span class="o">.</span><span class="s1">'views/'</span><span class="p">)</span>
|
|
<span class="p">{</span>
|
|
<span class="k">return</span> <span class="k">new</span> <span class="nx">\CodeIgniter\View\View</span><span class="p">(</span><span class="nv">$viewPath</span><span class="p">);</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>This sets the default path in the constructor method, but allows for easily changing
|
|
the path it uses:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$renderer</span> <span class="o">=</span> <span class="nx">\Config\Services</span><span class="o">::</span><span class="na">renderer</span><span class="p">(</span><span class="s1">'/shared/views'</span><span class="p">);</span>
|
|
</pre></div>
|
|
</div>
|
|
</div>
|
|
<div class="section" id="shared-classes">
|
|
<h3><a class="toc-backref" href="#id5">Shared Classes</a><a class="headerlink" href="#shared-classes" title="Permalink to this headline">¶</a></h3>
|
|
<p>There are occasions where you need to require that only a single instance of a service
|
|
is created. This is easily handled with the <code class="docutils literal"><span class="pre">getSharedInstance()</span></code> method that is called from within the
|
|
factory method. This handles checking if an instance has been created and saved
|
|
within the class, and, if not, creates a new one. All of the factory methods provide a
|
|
<code class="docutils literal"><span class="pre">$getShared</span> <span class="pre">=</span> <span class="pre">true</span></code> value as the last parameter. You should stick to the method also:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">Services</span>
|
|
<span class="p">{</span>
|
|
<span class="k">public</span> <span class="k">static</span> <span class="k">function</span> <span class="nf">routes</span><span class="p">(</span><span class="nv">$getShared</span> <span class="o">=</span> <span class="k">false</span><span class="p">)</span>
|
|
<span class="p">{</span>
|
|
<span class="k">if</span> <span class="p">(</span><span class="o">!</span> <span class="nv">$getShared</span><span class="p">)</span>
|
|
<span class="p">{</span>
|
|
<span class="k">return</span> <span class="k">new</span> <span class="nx">\CodeIgniter\Router\RouteCollection</span><span class="p">();</span>
|
|
<span class="p">}</span>
|
|
|
|
<span class="k">return</span> <span class="k">static</span><span class="o">::</span><span class="na">getSharedInstance</span><span class="p">(</span><span class="s1">'routes'</span><span class="p">);</span>
|
|
<span class="p">}</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
</div>
|
|
<div class="section" id="service-discovery">
|
|
<h3><a class="toc-backref" href="#id6">Service Discovery</a><a class="headerlink" href="#service-discovery" title="Permalink to this headline">¶</a></h3>
|
|
<p>CodeIgniter can automatically discover any ConfigServices.php files you may have created within any defined namespaces.
|
|
This allows simple use of any module Services files. In order for custom Services files to be discovered, they must
|
|
meet these requirements:</p>
|
|
<ul class="simple">
|
|
<li>It’s namespace must be defined <code class="docutils literal"><span class="pre">Config\Autoload.php</span></code></li>
|
|
<li>Inside the namespace, the file must be found at <code class="docutils literal"><span class="pre">Config\Services.php</span></code></li>
|
|
<li>It must extend <code class="docutils literal"><span class="pre">CodeIgniter\Config\BaseService</span></code></li>
|
|
</ul>
|
|
<p>A small example should clarify this.</p>
|
|
<p>Imagine that you’ve created a new directory, <code class="docutils literal"><span class="pre">Blog</span></code> in your root directory. This will hold a blog module with controllers,
|
|
models, etc, and you’d like to make some of the classes available as a service. The first step is to create a new file:
|
|
<code class="docutils literal"><span class="pre">Blog\Config\Services.php</span></code>. The skeleton of the file should be:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="o"><?</span><span class="nx">php</span> <span class="k">namespace</span> <span class="nx">Blog\Config</span><span class="p">;</span>
|
|
|
|
<span class="k">use</span> <span class="nx">CodeIgniter\Config\BaseService</span><span class="p">;</span>
|
|
|
|
<span class="k">class</span> <span class="nc">Services</span> <span class="k">extends</span> <span class="nx">BaseService</span>
|
|
<span class="p">{</span>
|
|
<span class="k">public</span> <span class="k">static</span> <span class="k">function</span> <span class="nf">postManager</span><span class="p">()</span>
|
|
<span class="p">{</span>
|
|
<span class="o">...</span>
|
|
<span class="p">}</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>Now you can use this file as described above. When you want to grab the posts service from any controller, you
|
|
would simply use the framework’s <code class="docutils literal"><span class="pre">Config\Services</span></code> class to grab your service:</p>
|
|
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$postManager</span> <span class="o">=</span> <span class="nx">Config\Services</span><span class="o">::</span><span class="na">postManager</span><span class="p">();</span>
|
|
</pre></div>
|
|
</div>
|
|
<div class="admonition note">
|
|
<p class="first admonition-title">Note</p>
|
|
<p class="last">If multiple Services file have the same method name, the first one found will be the instance returned.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
<div class="articleComments">
|
|
|
|
</div>
|
|
</div>
|
|
<footer>
|
|
|
|
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
|
|
|
|
<a href="http.html" class="btn btn-neutral float-right" title="Working With HTTP Requests" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
|
|
|
|
|
|
<a href="autoloader.html" class="btn btn-neutral" title="Autoloading Files" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
|
|
|
|
</div>
|
|
|
|
|
|
<hr/>
|
|
|
|
<div role="contentinfo">
|
|
<p>
|
|
© Copyright 2014-2019 British Columbia Institute of Technology.
|
|
Last updated on Mar 06, 2019.
|
|
|
|
</p>
|
|
</div>
|
|
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
|
|
|
|
</footer>
|
|
|
|
</div>
|
|
</div>
|
|
|
|
</section>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript">
|
|
var DOCUMENTATION_OPTIONS = {
|
|
URL_ROOT:'../',
|
|
VERSION:'4.0.0-beta.1',
|
|
COLLAPSE_INDEX:false,
|
|
FILE_SUFFIX:'.html',
|
|
HAS_SOURCE: false,
|
|
SOURCELINK_SUFFIX: ''
|
|
};
|
|
</script>
|
|
<script type="text/javascript" src="../_static/jquery.js"></script>
|
|
<script type="text/javascript" src="../_static/underscore.js"></script>
|
|
<script type="text/javascript" src="../_static/doctools.js"></script>
|
|
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript" src="../_static/js/theme.js"></script>
|
|
|
|
|
|
|
|
|
|
<script type="text/javascript">
|
|
jQuery(function () {
|
|
SphinxRtdTheme.StickyNav.enable();
|
|
});
|
|
</script>
|
|
|
|
|
|
</body>
|
|
</html> |