How to create custom action for sharepoint online 2013?through visual studio

Question

am trying to create a custom action for document library for sharepoint 2013 online but am unable to get it,can any one help?

Answer 1

You can use Client object model csom c# to create custom action. Try below code:

public static void AddCustomListAction(ClientContext clientContext)
{
    string title = "Test Ribbon Action";

    List list = clientContext.Web.Lists.GetByTitle("Test"); 
    UserCustomActionCollection collUCA = list.UserCustomActions;
    clientContext.Load(collUCA);
    clientContext.ExecuteQuery();

    bool found = false;
    UserCustomAction newUCAToRemove = null;
    for (int i = 0; i < collUCA.Count; i++)
    {
        if (collUCA[i].Title == title)
        {
            newUCAToRemove = collUCA[i];
            found = true;
            break;
        }
     }

     if (found)
     {
         newUCAToRemove.DeleteObject();
     }

     // Always replace existing custom action
     UserCustomAction action = collUCA.Add();
     action.Location = "CommandUI.Ribbon.ListView";
     action.Sequence = 1000;
     action.Title = title;
     action.CommandUIExtension = @"<CommandUIExtension><CommandUIDefinitions>"
            + "<CommandUIDefinition Location=\"Ribbon.ListItem.Actions.Controls._children\">"
            + "<Button Id=\"InvokeAction.Button\" TemplateAlias=\"o1\" Command=\"Invoke_Command\" CommandType=\"General\" LabelText=\"Publish new items\" Image32by32=\"_layouts/15/images/placeholder32x32.png\" Image16by16=\"_layouts/15/images/placeholder16x16.png\" />"
            + "</CommandUIDefinition>"
            + "</CommandUIDefinitions>"
            + "<CommandUIHandlers>"
            + "<CommandUIHandler Command =\"Invoke_Command\" CommandAction=\"javascript:customFunction();\" />"
            + "</CommandUIHandlers></CommandUIExtension>";

     action.Update();

     clientContext.ExecuteQuery();

}

Here, using the above code, a custom javascript method, javascript:customFunction() ,would be called which would be defined on the page/masterpage/page layout etc.

Output would be similar to below screengrab:

Reference - UserCustomAction class

UCA using powershell

UCA using CSOM C#