Location

CHAN Reference

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Name Location
CSS Class NA
Type NA

The Location object represents a middle ground between Javascript's window.location and .Net's URI class. Various controls use a Location object to build their paths, for example the Form's action attribute.

The Chan.Page base class has a built in Location object that represents that page, it is this that child controls key off, so if you wanted a form to post back - but include or exclude a particular value from the querystring you can alter the page's Location.QueryString collection directly. This is in contrast to standard ASPX's Page.QueryString which is read only.

You can also spawn and manipulate your own Location objects as and when you need them, or Clone() them from the current page to start with a Location that represents the current page, then alter the querystring to suit, making for very simple construction of links and actions without needing to do any string manipulation.

Once you've built up a Location object you can assign it to a Link Href or even Response.Redirect to it by simply reading the Href or RelativeHref string properties, no string concatanation neccesary.

Qualifiers	Type	Name	Default	Description
	string	Hash	""	The named anchor within the page to navigate to, without a leading "#" - though you may set it with one. This will be "" when the Page loads because most browsers do not send it via http, but you can use it for link creation.
	string	Host	""	The site/hostname portion of the url. E.g. "www.example.com"
	string	Path	""	Any sub directory paths after the host, with a leading "/", though you may set it without one. E.g. "/virtdir/"
	string	Page	""	The page name, can be left empty to request the default page (i.e. "Default.aspx"). E.g. "About_Us.aspx"
	int	Port	80	The port number, if Protocol is "http" and Port is 80 then the port will not be rendered, the same applies for "ftp"/21 and "https"/443
	string	Protocol	"http"	The protocol that the link will use, without a trailing ":", though you may set it with one
	NameValueCollection	QueryString	(empty)	The key/value pairs as found in the querystring, it is fully public so you can add and remove values from the collection as well as assign your own NameValueCollection directly by reference
readonly	string	Href		Mirrors Javascript window.location.href, includes Protocol, Host and Port. Note: This is rebuilt every time the property is read, you may want to cache it in a local string if you need it more than once.
readonly	string	RelativeHref		Mirrors Javascript window.location.href, excludes Protocol, Host and Port. Note: This is rebuilt every time the property is read, you may want to cache it in a local string if you need it more than once.
readonly	string	Search		Mirrors Javascript window.location.search, includes leading "?" but excludes trailing Hash. Note: This is rebuilt every time the property is read, you may want to cache it in a local string if you need it more than once.
readonly	string	ToString()		Equivelant to Href

ASPX

    <Chan:Image runat="server" id="lnkFirst" Text="First" Path="[Icon.Go_First]" />
    <Chan:Image runat="server" id="lnkPrev" Text="Previous" Path="[Icon.Go_Prev]" />
    <Chan:Label runat="server" id="lblPage" />
    <Chan:Image runat="server" id="lnkNext" Text="Next" Path="[Icon.Go_Next]" />
    <Chan:Image runat="server" id="lnkLast" Text="Last" Path="[Icon.Go_Last]" />

CS

using System;
using Chan;

    protected override void Page_Init()
    {
        int iNumPages = 5;
        int iCurPage = 1;
        
        // Check if we have a current page number in the Chan.Page built-in Location instance
        if( !String.IsNullOrEmpty( Location.QueryString["Page"] ) )
            Int32.TryParse(Location.QueryString["Page"] , out iCurPage );
        
        // Start with the current URL
        Location loc = this.Location.Clone();
        
        // Can only go to Previous or First page if we're not at page 1
        if( iCurPage > 1 )
        {
            //No need to Add() the Key if it does not exist
            loc.QueryString["Page"] = "1";
            lnkFirst.Link = loc.RelativeHref;
			
            //No need to Clone a new Location for every link as only one parameter changes
            loc.QueryString["Page"] = (iCurPage - 1).ToString();    
            lnkPrev.Link = loc.RelativeHref;
        }
        else
        {
            lnkFirst.Enabled = false;
            lnkPrev.Enabled = false;
        }            
        
        // Can only go to Next or Last page if we're not at the last page
        if( iCurPage < iNumPages )
        {
            //Value is a string so we must ToString() all our ints
            loc.QueryString["Page"] = iNumPages.ToString();
            lnkLast.Link = loc.RelativeHref;
            
            loc.QueryString["Page"] = (iCurPage + 1).ToString();
            lnkNext.Link = loc.RelativeHref;
        }
        else
        {
            lnkLast.Enabled = false;
            lnkNext.Enabled = false;
        }
        
        // Render the label in the centre
        lblPage.Text = Generic.Concat( iCurPage.ToString() , " of " , iNumPages.ToString() );
    }

CYCLOMEDIA

CHAN Reference

Location

ASPX

CS