~~Title: Adding a new Column ~~
<pageheader/>

This is an example of a [[..:script_add-ins|script add-in]] that adds a new information column to Opus.

This column, **Is Modified?**, indicates whether a file has been modified since it was created. This is performed by simply comparing whether the item's creation and modification dates are the same.

  * For files that have been modified, the column displays //Yes//, and for files that haven't been modified it displays //No//. Nothing is displayed for folders. 
  * When sorting by this column, modified files are displayed above non-modified files. 
  * When grouping by this column, the two groups are labeled //Modified// and //Never Modified//. 



The basic procedure to add a custom column from a [[..:script_add-ins|script add-in]] is:



  * Either: 
    * In the **[[:reference:scripting_reference:scripting_events:oninit|OnInit]]** event, create a **[[:reference:scripting_reference:scripting_objects:scriptcolumn|ScriptColumn ]]**object with the **[[:reference:scripting_reference:scripting_objects:scriptinitdata|ScriptInitData]].AddColumn** method. 
    * Or, in the **[[:reference:scripting_reference:scripting_events:onaddcolumns|OnAddColumns]]** event, create a **[[:reference:scripting_reference:scripting_objects:scriptcolumn|ScriptColumn ]]**object with the **[[:reference:scripting_reference:scripting_objects:addcoldata|AddColData]].AddColumn** method. 

  * Initialize the properties of the **[[:reference:scripting_reference:scripting_objects:scriptcolumn|ScriptColumn** ]]**object. At a minimum you must populate the **name** and **method** properties. * Create a separate function in your script-add in, with the **method** name you specified for the column. This method will be called when Opus wants to retrieve data for your column. 

<code>
// Set the script type to JScript to use this script
// The OnInit function is called by Directory Opus to initialize the script add-in
function OnInit(initData)
{
    // Provide basic information about the script by initializing the properties of the ScriptInitData object
    initData.name = "Is Modified Column";
    initData.desc = "Adds a column that indicates if a file has ever been modified.";
    initData.copyright = "(c) 2014 Jonathan Potter";
    initData.default_enable = true; // Create a new ScriptColumn object and initialize it to add the column to Opus
    var cmd = initData.AddColumn();
    cmd.name = "IsModified";
    cmd.method = "OnIsModified";
    cmd.label = "Is Modified?";
    cmd.autogroup = false; // we provide our own grouping information
    cmd.autorefresh = true; // refresh column when files change
    cmd.justify = "center";
    cmd.match.push_back("Yes"); // when searching, these are the only two options
    cmd.match.push_back("No");
}

// Implement the IsModified column (this entry point is an OnScriptColumn event).
// The name of this function must correspond to the value specified for the **method **property when the column was added in OnInit
function OnIsModified(scriptColData)
{
    // scriptColData is a ScriptColumnData object.
    // First check that this is the right column (it should be since we only added one).
    if (scriptColData.col != "IsModified")
        return;
    // We don't provide a value for folders since their timestamps don't mean much.
    // We set the sort key to 3 so they come last (in case the user is mixing files and folders).
    if (scriptColData.item.is_dir)
    {
        scriptColData.value = "";
        scriptColData.sort = 3;
    }
    // For files, are the two dates the same?
    else if (new Date(scriptColData.item.create).valueOf() == new Date(scriptColData.item.modify).valueOf())
    {
        scriptColData.value = "No";
        scriptColData.group = "Never Modified";
        scriptColData.sort = 2;
    }
    // the dates are different, therefore modified
    else
    {
        scriptColData.value = "Yes";
        scriptColData.group = "Modified";
        scriptColData.sort = 1;
    }
}
</code>