chrome/common/extensions/docs/templates/intros/fileBrowserHandler.html

   1 <p>
   2 The Chrome OS file browser comes up when
   3 the user either presses Alt+Shift+M
   4 or connects an external storage device,
   5 such as an SD card, USB key, external drive, or digital camera.
   6 Besides showing the files on external devices,
   7 the file browser can also display files
   8 that the user has previously saved to the system.
   9 </p>
  10
  11 <p>
  12 When the user selects one or more files,
  13 the file browser adds buttons
  14 representing the valid handlers for those files.
  15 For example, in the following screenshot,
  16 selecting a file with a ".jpg" suffix
  17 results in an "Upload to Picasa" button that the user can click.
  18 </p>
  19
  20 <p>
  21 <img src="{{static}}/images/filebrowserhandler.png"
  22   width="640" height="400" alt="file browser screenshot" />
  23 </p>
  24
  25
  26 <h2 id="manifest">Manifest</h2>
  27
  28 <p>
  29 You must declare the "fileBrowserHandler" permission
  30 in the <a href="manifest">extension manifest</a>,
  31 and you must use the "file_browser_handlers" field
  32 to register the extension as a handler of at least one file type.
  33 You should also provide a 16x16 icon
  34 to be displayed on the button.
  35 For example:
  36 </p>
  37
  38 <pre data-filename="manifest.json">
  39 {
  40   "name": "My extension",
  41   ...
  42   <b>"file_browser_handlers"</b>: [
  43     {
  44       <b>"id"</b>: "upload",
  45       <b>"default_title"</b>: "Save to Gallery", <em>// What the button will display</em>
  46       <b>"file_filters"</b>: [
  47         "filesystem:*.jpg", <em>// To match all files, use "filesystem:*.*"</em>
  48         "filesystem:*.jpeg",
  49         "filesystem:*.png"
  50       ]
  51     }
  52   ]</b>,
  53   "permissions" : [
  54     <b>"fileBrowserHandler"</b>
  55   ],
  56   "icons": { <b>"16"</b>: "icon16.png",
  57              "48": "icon48.png",
  58             "128": "icon128.png" },
  59   ...
  60 }
  61 </pre>
  62
  63 <p class="note">
  64 <b>Note:</b>
  65 You can specify locale-specific strings for the value of "default_title".
  66 See <a href="i18n">Internationalization (i18n)</a> for details.
  67 </p>
  68
  69 <h2 id="code">Implementing a file browser handler</h2>
  70
  71 <p>
  72 To use this API,
  73 you must implement a function that handles the <code>onExecute</code> event
  74 of <code>chrome.fileBrowserHandler</code>.
  75 Your function will be called whenever the user clicks the button
  76 that represents your file browser handler.
  77 In your function, use the HTML5
  78 <a href="http://www.html5rocks.com/tutorials/file/filesystem/">FileSystem API</a>
  79 to get access to the file contents.
  80 Here is an example:
  81 </p>
  82
  83 <pre data-filename="background.js">
  84 chrome.fileBrowserHandler.onExecute.addListener(function(id, details) {
  85   if (id == 'upload') {
  86     var fileEntries = details.entries;
  87     for (var i = 0, entry; entry = fileEntries[i]; ++i) {
  88       entry.file(function(file) {
  89         <em>// send file somewhere</em>
  90       });
  91     }
  92   }
  93 });
  94 </pre>
  95
  96 <p>
  97 Your event handler is passed two arguments:
  98 </p>
  99
 100 <dl>
 101   <dt> id </dt>
 102   <dd> The "id" value from the manifest file.
 103        If your extension implements multiple handlers,
 104        you can check the <code>id</code> value
 105        to see which handler has been triggered.
 106        </dd>
 107   <dt> details </dt>
 108   <dd> An object describing the event.
 109        You can get the file or files that the user has selected
 110        from the <code>entries</code> field of this object,
 111        which is an array of
 112        FileSystem <code>Entry</code> objects.
 113        </dd>
 114 </p>
 115
 116
 117 <!--
 118 <h2 id="manifest_details">Manifest details</h2>
 119
 120 <p class="authornote">
 121 {PENDING: give details about "id" and "default_title".
 122 It should be unique within your extension -- don't worry about other extensions.
 123 "default_title" implies that you can change the title,
 124 but you can't aside from internationalizing it.
 125 </p>
 126
 127 <p class="authornote">
 128 {PENDING: give details about the file_filters entry.
 129 File filters are currently case-sensitive, but we plan to change that.
 130 Mention <code>filesystem:*.*</code>.
 131 </p>
 132 -->
 133
 134 <!--
 135 <h2 id="examples">Examples</h2>
 136
 137 <p>
 138 For examples of using this API, see ...
 139 For other examples and for help in viewing the source code, see
 140 <a href="samples">Samples</a>.
 141 </p>
 142 -->