Public Class GeoffAppleby : Adding an Image to a Community Server RSS Feed

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Adding an Image to a Community Server RSS Feed

I realised through the week that my RSS feed didn't include an image within the channel definition - and so I decided that I needed to do something about it :) After researching what was needed to get an image into a feed (this is at the top of the feed, not within a blog post) it was pretty straight forward to add it to not only my own feed, but tor make it configurable for anyone on the CrankyGoblin blogs site.

First, I needed to make the URL for the image a property of a blog. So in Weblog.cs (CommunityServer.Blogs.Components) I added this property:

public string RssImageUrl
{
    get { return GetString("RssImageUrl", null); }
    set { SetExtendedAttribute("RssImageUrl", value); }
}

Then I needed a way to set the value within the control panel. So to DescOptions.aspx (Web/ControlPanel/Blogs):

<DIV class="CommonFormFieldName">
    <CP:helpicon id="Helpicon5" runat="server" Text="Enter the URL for the image you want embedded within your RSS feed."></cp:helpicon>
    <CP:FormLabel id="FormLabel5" runat="server" Text="RSS Image URL" ControlToLabel="RssImageUrl"></CP:FormLabel>
</DIV>
<DIV class="CommonFormField">
    <asp:TextBox id="RssImageUrl" Runat="Server" CssClass="ControlPanelTextInput" ></asp:TextBox>
</DIV>

And in the code behind for that page (DescOptions.aspx.cs) we have to get a handle on the new textbox, set the current value on the textbox, and update the value on the Weblog object on save.

Up near the top of the file, add a field and update the Page_Load event:

protected TextBox RssImageUrl;
 
private void Page_Load(object sender, EventArgs e)
{
    if(!IsPostBack)
    {
        TitleValidator.Text = ResourceManager.GetString("CP_Blogs_DescOptions_BlogTitle_Required");
        Title.Text = this.CurrentWeblog.Name;
        Description.Text = this.CurrentWeblog.Description;
        News.Text = this.CurrentWeblog.News;
        FavIcon.Text = this.CurrentWeblog.FavIcon;
        RssImageUrl.Text = this.CurrentWeblog.RssImageUrl;
    }
}

And in the SaveButton click event:

private void SaveButton_Click(object sender, EventArgs e)
{
    if(Page.IsValid)
    {
        CurrentWeblog.Name = Title.Text;
        CurrentWeblog.Description = Description.Text;
        CurrentWeblog.News = News.Text;
        CurrentWeblog.FavIcon = FavIcon.Text;
        CurrentWeblog.RssImageUrl = RssImageUrl.Text;
        Weblogs.Update(CurrentWeblog);

This takes care of saving and editing what image we'd like included in our Rss feed.

Now we need to update the actual RSS XML. To do it nice, I only wanted to modify the channel stuff when it was a blog, not anything else - the logical place is to do it in the WeblogRssWriter (CommunityServer.Blogs.Components, in the Syndication folder) - but to override that BuildChannel() method, first we need to make the base class's BuildChannel() method overridable. So first in BaseRssWriter (CommunityServer.Components, in the Syndication folder) I made the to overloads virtual:

protected virtual void BuildChannel(string link, string description)
{
    BuildChannel(link,description,"en-US");
}
 
protected virtual void BuildChannel(string link, string description, string lang)
{
    this.WriteElementString("title", Title);            
    this.WriteElementString("link", FormatUrl(link));
    this.WriteElementString("description", description);
    this.WriteElementString("dc:language", lang);
    this.WriteElementString("generator", SiteStatistics.CommunityServerVersionVersionInfo);
}

And then back in WeblogRssWriter.cs I was able to add these two methods:

protected override void BuildChannel(string link, string description)
{
    BuildChannel(link, description, "en-US");
}
 
protected override void BuildChannel(string link, string description, string lang)
{
    base.BuildChannel(link, description, lang);
    if (CurrentWeblog.RssImageUrl != null && CurrentWeblog.RssImageUrl != string.Empty && CurrentWeblog.RssImageUrl.Trim().Length > 0)
    {
        this.WriteStartElement("image");
        this.WriteElementString("link", FormatUrl(link));
        this.WriteElementString("title", Title);
        this.WriteElementString("url", CurrentWeblog.RssImageUrl);
        this.WriteEndElement();
    }
}