1 <h2 id="manifest">Manifest</h2> 2 <p>You must declare the "contentSettings" permission 3 in your extension's manifest to use the API. 4 For example:</p> 5 <pre data-filename="manifest.json"> 6 { 7 "name": "My extension", 8 ... 9 <b>"permissions": [ 10 "contentSettings" 11 ]</b>, 12 ... 13 } 14 </pre> 15 16 17 <h2 id="patterns">Content setting patterns</h2> 18 <p> 19 You can use patterns to specify the websites that each content setting affects. 20 For example, <code>http://*.youtube.com/*</code> specifies youtube.com and all 21 of its subdomains. The syntax for content setting patterns is the same as for 22 <a href="match_patterns">match patterns</a>, with a few differences: 23 <ul><li>For <code>http</code>, 24 <code>https</code>, and <code>ftp</code> URLs, the path must be a wildcard 25 (<code>/*</code>). For <code>file</code> URLs, the path must be completely 26 specified and <strong>must not</strong> contain wildcards.</li> 27 <li>In contrast to match patterns, content setting patterns can specify a port 28 number. If a port number is specified, the pattern only matches websites with 29 that port. If no port number is specified, the pattern matches all ports. 30 </li> 31 </ul> 32 </p> 33 34 <h3 id="pattern-precedence">Pattern precedence</h3> 35 <p> 36 When more than one content setting rule applies for a given site, the rule with 37 the more specific pattern takes precedence. 38 </p> 39 <p>For example, the following patterns are ordered by precedence:</p> 40 <ol> 41 <li><code>http://www.example.com/*</code></li> 42 <li><code>http://*.example.com/*</code> (matching 43 example.com and all subdomains)</li> 44 <li><code><all_urls></code> (matching every URL)</li> 45 </ol> 46 <p> 47 Three kinds of wildcards affect how specific a pattern is: 48 </p> 49 <ul> 50 <li>Wildcards in the port (for example 51 <code>http://www.example.com:*/*</code>)</li> 52 <li>Wildcards in the scheme (for example 53 <code>*://www.example.com:123/*</code>)</li> 54 <li>Wildcards in the hostname (for example 55 <code>http://*.example.com:123/*</code>)</li> 56 </ul> 57 <p> 58 If a pattern is more specific than another pattern in one part but less specific 59 in another part, the different parts are checked in the following order: 60 hostname, scheme, port. For example, the following patterns are ordered by 61 precedence:</p> 62 <ol> 63 <li><code>http://www.example.com:*/*</code><br> 64 Specifies the hostname and scheme.</li> 65 <li><code>*:/www.example.com:123/*</code><br> 66 Not as high, because although it specifies the hostname, it doesn't specify 67 the scheme.</li> 68 <li><code>http://*.example.com:123/*</code><br> 69 Lower because although it specifies the port and scheme, it has a wildcard 70 in the hostname.</li> 71 </ol> 72 73 <h2 id="primary-secondary">Primary and secondary patterns</h2> 74 <p> 75 The URL taken into account when deciding which content setting to apply depends 76 on the content type. For example, for 77 $(ref:contentSettings.notifications) settings are 78 based on the URL shown in the omnibox. This URL is called the "primary" URL.</p> 79 <p> 80 Some content types can take additional URLs into account. For example, 81 whether a site is allowed to set a 82 $(ref:contentSettings.cookies) is decided based on the URL 83 of the HTTP request (which is the primary URL in this case) as well as the URL 84 shown in the omnibox (which is called the "secondary" URL). 85 </p> 86 <p> 87 If multiple rules have primary and secondary patterns, the rule with the more 88 specific primary pattern takes precedence. If there multiple rules have the same 89 primary pattern, the rule with the more specific secondary pattern takes 90 precedence. For example, the following list of primary/secondary pattern pairs 91 is ordered by precedence:</p> 92 <table> 93 <tr><th>Precedence</th><th>Primary pattern</th><th>Secondary pattern</th> 94 <tr> 95 <td>1</td> 96 <td><code>http://www.moose.com/*</code>, </td> 97 <td><code>http://www.wombat.com/*</code></td> 98 </tr><tr> 99 <td>2</td> 100 <td><code>http://www.moose.com/*</code>, </td> 101 <td><code><all_urls></code></td> 102 </tr><tr> 103 <td>3</td> 104 <td><code><all_urls></code>, </td> 105 <td><code>http://www.wombat.com/*</code></td> 106 </tr><tr> 107 <td>4</td> 108 <td><code><all_urls></code>, </td> 109 <td><code><all_urls></code></td> 110 </tr> 111 </table> 112 113 <h2 id="resource-identifiers">Resource identifiers</h2> 114 <p> 115 Resource identifiers allow you to specify content settings for specific 116 subtypes of a content type. Currently, the only content type that supports 117 resource identifiers is $(ref:contentSettings.plugins), 118 where a resource identifier identifies a specific plug-in. When applying content 119 settings, first the settings for the specific plug-in are checked. If there are 120 no settings found for the specific plug-in, the general content settings for 121 plug-ins are checked. 122 </p> 123 <p> 124 For example, if a content setting rule has the resource identifier 125 <code>adobe-flash-player</code> and the pattern <code><all_urls></code>, 126 it takes precedence over a rule without a resource identifier and the pattern 127 <code>http://www.example.com/*</code>, even if that pattern is more specific. 128 </p> 129 <p> 130 You can get a list of resource identifiers for a content type by calling the 131 $(ref:contentSettings.ContentSetting.getResourceIdentifiers) method. The returned list 132 can change with the set of installed plug-ins on the user's machine, but Chrome 133 tries to keep the identifiers stable across plug-in updates. 134 </p> 135 136 <h2 id="examples">Examples</h2> 137 138 <p> 139 You can find samples of this API on the 140 <a href="samples#contentSettings">sample page</a>. 141 </p> 142
