Getting a Repeater/GridView to show child values of relationships with Entities

Once again, it is a bit more involved than L2S, but relatively simple

I have made L2S my go-to for a while now, and I will keep referring back to it as a baseline of how ORMs *should* work. When I am using a repeater, and I want to show a related object value, I can simply do this with L2S (same syntax for L2E as well):
<%# Eval("state.state_name") %>

Where 'state' is a related object. Similarly, if I try the same thing in L2E, it will not error out, it will just show up blank (I would much prefer an error). Like I said, the syntax is the exact same for that part, it is just different when you are getting your data. You now need to explicitly include what child objects you want to load with your data. So, for the above example, I could something like this:

linq-to-sql
var results = from p in db.records select p;
Repeater1.DataSource = results;
Repeater1.DataBind();

But, to get anything other than blanks to show up with L2E, I need to change it a bit:

linq-to-entities
var results = from p in db.records.Include("state") 
  select p;
Repeater1.DataSource = results;
Repeater1.DataBind();

Now it knows that 'state' has to be loaded with the original records. You can chain mulitple Include()s along to include more and more stuff as well:

linq-to-entities
var results = from p in 
  db.records.Include("state").Include("city")
  select p;

Inserting New Items Into a Table : 'REAL' AJAX with Asp.Net Series

Add a new item into the table and database and have it immediately sortable, pageable, etc without any postback

This is a continuation of my 'REAL' AJAX with Asp.Net (not Asp.Net AJAX) series posts for those of us trying to stop relying on Asp.Net 'AJAX'.

This is probably the hardest part about a full CRUD (Create, Read, Update, Delete) system, but as we have already covered 'RUD', it's time to hit the 'C'. First of all, we have to break down what will be happening, both on the client-side, and the server side, then it will be easier to dissect.
  1. User pulls up a 'New Entry' dialogue (client)
  2. User enters information and it is validated (client*)
  3. Valid information is sent to the server (client)
  4. Server attempts to add in new item (server)
  5. Server spits back status update (server)
  6. status update is displayed (client)
  7. item is added into the visible table (client)
  8. input fields are cleared and the input dialogue is hidden (client)

The * above denotes that while in this example we are doing only client-side validation, it is in your best interest to add in some server side as well (keep in mind that this example will not work without javascript, so it is not robust and does not 'gracefully' degrade).

As you can see, most of the heavy lifting here is done on the client side, with the dedicated server doing just a couple things.

set up the entry dialogue

First I am adding a couple divs which will be clicked to open the dialogue:

insert.aspx

<div class="button triggerNew">New Entry</div>


In the CSS, you can see that these will render like buttons:

demo.css
.button 
{ 
    width: 100px; 
    font-weight: bold; 
    border: outset 2px blue; 
    padding: 1px; 
    text-align: center; 
    color: Blue; 
}
.button:hover 
{ 
    border-style: inset; 
    cursor: pointer; 
    padding: 2px 0 0 2px; 
}

To go with the whole ajax feel, I am setting up the entry in a modal popup; you probably noticed the class 'triggerNew' which isn't really a css class, but it will be used to by jQuery to hook into any elements that have that class and tie them to the modal. To do that first we must include the jquery.jqModal plugin (which IMO is the best modal plugin as it is minimalist and customizable as well as easy to use) in our masterpage.
demo.master

<script type="text/javascript" src="js/jquery.jqModal.js"></script>


As for the modal popup, here is the markup:

<div class="jqmWindow" id="new">
  <h3 class="modal_header">
    <div class="working">working...</div>
    <a href="#" class="x jqmClose">X</a>
    Add New Entry
  </h3>
  <div class="pad">
    <div class="left">
      <h4>
        <asp:RequiredFieldValidator ID="rfvFirst" ControlToValidate="txtFirst" CssClass="right"
          ErrorMessage="required" runat="server" ValidationGroup="new" />
        First Name
      </h4>
      <input type="text" ID="txtFirst" runat="server" />
    </div>
    <div class="left">
      <h4>
        <asp:RequiredFieldValidator ID="rfvLasst" ControlToValidate="txtLast" CssClass="right"
          ErrorMessage="required" runat="server" ValidationGroup="new" />
        Last Name
      </h4>
      <input type="text" ID="txtLast" runat="server" />
    </div>
    <div class="left">
      <h4>
        <asp:RegularExpressionValidator ID="regAge" ControlToValidate="txtAge" CssClass="right"
          ErrorMessage="1-3 digits" runat="server" Display="dynamic" ValidationGroup="new" />
        <asp:RequiredFieldValidator ID="rfvAge" ControlToValidate="txtAge" CssClass="right"
          ErrorMessage="required" runat="server" Display="dynamic" ValidationGroup="new" />
        Age
      </h4>
      <input type="text" ID="txtAge" runat="server" />
    </div>
    <div class="summary">
      <div id="submit" class="button">Submit</div>
    </div>
  </div>
</div>


Now there is a lot going on there. First of all, I used the Asp.Net validators as we are most familiar with them, and they play nicely with jQuery. Also, I am not using asp:TextBoxes at all, I am sticking with the basic input boxes. But, because I am using the Asp.Net Validators, I still need to include runat="server" with each input that I Validate; this also means that they will get weird Asp.Net IDs and not the exact ones I assign them. All I am doing here is making sure all the fields have values, and that age is a diget with 1-3 digits (yes, someone can be 999 in this system...).

In addition, the css class 'jqmClose' class is included in a link: this will automatically be assigned to close the modal window by jqModal.

I also put an additional 'working' element in there so the user can see that dialogue while the program is running its magic.

But as it stands now, we can't even see that popup, get the validators to fire or submit any sort of data. Here comes the jQuery.

work the jQuery magic

Here is the script, it is explained in the comments:
//assign all 'triggerNew' elements to open the modal dialogue
$('#new').jqm({ trigger: false }).jqmAddTrigger($('.triggerNew'));

//attach this event to the clicking of the 'submit' div
$("#submit").click(function() {
    //will not do anything if the validators don't check out
    //Page_ClientValidate('ValidationGroup') is an Asp.Net generated function
    if (!Page_ClientValidate('new')) { return false; }
    else {
        // get the values from the textboxes into an array
        // notice that this is using .ClientID to get the strange Asp.Net ID assigned to it
        var vals = [
            $("#<%= txtFirst.ClientID %>"),
            $("#<%= txtLast.ClientID %>"),
            $("#<%= txtAge.ClientID %>")
        ];
        // do the ajax post
        $.post(
            //function is at
            "ajax_functions/insert.aspx",
            //send the values frorm the vals object
            { first: vals[0].val(), last: vals[1].val(), age: vals[2].val() },
            function(data) {
                //output the return data
                $("#report").html(data);
                // the class 'success' was sent back if it worked...
                var success = (data.toString().substring(12, 19) == "success");
                //add the new data into the table so the user can see it if it was successful
                if (success) {
                    oTable.fnAddData([
                    vals[0].val(),
                    vals[1].val(),
                    vals[2].val(),
                    '&nbsp;'
                ]);
                    //clear the textboxes
                    $(vals).each(function() { $(this).val('') });
                }
                //hide the modal now that it's done
                $('#new').jqmHide();
            }
        );
    }
});

Note that this will not allowed items added since the last postback to be deleted/edited, that is why the last cell simpy gets an '&nbsp;'. Keep in mind that it is possible, just beyond the scope of this tutorial.

Also, in a ghetto form of error reporting, I passed the css class which will either be 'error' on error, or 'success' otherwise.  We can use that to decide whether or not to post the new data into the table and to clear the inputs.  This will catch any errors that we did not already account for.

Really all that remains is the server-side part, we need to make the page that is called: "ajax_functions/insert.aspx" to handle the inputs passed.

server-side functions

Notice this time that we used a $.post() method, which sends the stated values and returns something - in this case, we are having it return a chunk of html which will tell us what happened with the server, and it will be pushed into the 'report' div. Here is our server operations:

ajax_functions/insert.aspx.cs
using System;

public partial class ajax_functions_insert : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        demoDataContext db = new demoDataContext();
        try
        {
            // get all the new values
            string first = Request.Form[0];
            string last = Request.Form[1];
            int age = Convert.ToInt32(Request.Form[2]);

            //make a new person
            person p = new person()
            {
                first_name = first,
                last_name = last,
                age = age
            };

            //insert them into the db
            db.persons.InsertOnSubmit(p);
            db.SubmitChanges();

            //if it was all successful
            Response.Write("<div class='success'>" + first + " " + last + " [" + age + "] inserted</div>");
        }
        // this will catch all the errors and output an error message if caught
        catch (Exception ex) 
        {
            Response.Write("<div class='success'>Error: " + ex.Message +"</div>");
        }
    }
}

As usual, this is the easy part. Now you have a full working CRUD system, with some pretty good error catching as such with absolutely no postbacks! Ajax is fun and can be quite useful, I hope these tutorials helped make it a little more accessible to some Asp.Net devs, I know I learned a lot making them.

« Deleting

Use and Manipulate Asp.Net Validators with jQuery and/or Javascript

Asp.Net has some great validation included - no need to learn new validation, just grab them with client-side scripting

The problem I found when going into jQuery validation, is that they mostly seem to assume that you can have more than one form on your page; which, for us Asp.Net devs, is not the case. After some digging, I figured out how to use the current validators which I am already familiar with (RegularExpressionValidator, RequiredFieldValidator, etc.) and just hook into them with javascript; no need to reinvent the wheel. It is very easy, and we don't lose the server-side validation that is so great with the Asp.Net validators (if you call on it that is).

want to make a certain validator(s) fire?

Let's say I have a RequiredFieldValidator named 'rfvFirst' and I want it to test for validation on the click event of the element with id 'some_link'. With jQuery, this is what I would do:
$("#some_link").click(function() {
    ValidatorValidate($("#<%= rfvFirst.ClientID %>")[0]);
});

Now, the ErrorMessage of 'rfvFirst' will show if it is not valid - it will behave just as if you tried to submit the form, but just for that validator itself. Notice that I am using <%= rfvFirst.ClientID %> which will pull the crazy Asp.Net id that is produced in Asp.net which is often something strange like 'ctl00_ContentPlaceHolder1_rfvFirst'.  Now, if you want to use a class or something else to select the Validators, that is fine too.  This will fire all of the Validators that have the CssClass 'fire':
$(".fire").each(function() {
    ValidatorValidate($(this)[0]);
});

want to have a button/link cause validation and only work if the page is valid?

For this, you need to make sure your validators each have a ValidationGroup set. In this example I am attaching it to a button with id 'submit' and the ValidationGroup 'new'. Simply attach the click event to Page_ClientValidate() method:
$("#submit").click(function() {
    return Page_ClientValidate('new');
});

This was the only method I found that actually returned something that could be used to tell if the page was valid (I am far from a JS pro). There is likely more ways to do this and I am interested in any that people have found!

want to stroll through the validators?

The are all held in an object (array) 'Page_Validators' and you can access it like any other array, looping or whatever. This will look through and output into the 'report' element the ids of all the Validators you have on your page:
for(var i=0,len=Page_Validators.length;i<len;++i){
    $("#report").append($(Page_Validators[i]).attr('id'));
    $("#report").append("<br />");
}

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Deleting Items From a Table : 'REAL' AJAX with Asp.Net Series

Delete an entry from the DB and remove the corresponding row from the table; plus an ajax loading indicator

This is a continuation of my 'REAL' AJAX with Asp.Net (not Asp.Net AJAX) series posts for those of us trying to stop relying on Asp.Net 'AJAX'.

GridView has an incredibly easy 'Delete' feature when used in conjunction with a DataSource, the problem is, that is requires a postback. Since we are going the ajax route, this is a no-go. Alternatively, we could wrap in in an UpdatePanel, but that is exactly what we are trying to avoid. Deleting is very easy, we use a lot of the same methods that were involved in fixing the sort on the last post and using the jQuery .ajax() method.

changes to the markup

First we have to add another column for deleting and stick a delete image in there, this is simple enough. I added unique ids to each row and each delete cell for jQuery to have something to hook on to, you could also add classes. The markup hasn't changed all too much:

delete.aspx

<asp:Repeater ID="rpt" runat="server" DataSourceID="lds">
  <HeaderTemplate>
    <table id="sort_table">
      <thead>
        <tr>
          <th>First</th><th>Last</th><th>Age</th><th></th>
        </tr>
      </thead>
      <tbody>
  </HeaderTemplate>
  <ItemTemplate>
    <tr>
      <td id="frst<%#Eval("person_id")%>" class="editable">
        <%#Eval("first_name")%>
      
</td>
      <td id="last<%#Eval("person_id")%>" class="editable">
        <%#Eval("last_name")%>
      
</td>
      <td id="age_<%#Eval("person_id")%>" class="editable">
        <%#Eval("age")%>
      
</td>
      <td style="test-align:right;" id="del_<%#Eval("person_id")%>">
        <img src="images/delete_item.png" alt="delete" />
      </td>
    </tr>
  </ItemTemplate>
  <FooterTemplate>
    </tbody></table>
  </FooterTemplate>
</asp:Repeater>
<asp:LinqDataSource ID="lds" runat="server"
  ContextTypeName="demoDataContext" TableName="persons" />


We put the id on the cell itself and not the image because it will be easier to grab with dataTables, not to mention easier to click.

now for the js

First of all, you will notice if we leave the .dataTables() call the same as before, you can now 'sort' by the last column (the delete column), that isn't right, we have to pass some parameters to our 'dataTables()' method to make sure that column gets ignored:
oTable = $("#sort_table").dataTable({
    "aoColumns": [null, null, null, { "bSortable": false}]
});

Also notice that we decided to store the resulting table in 'oTable' just like the last lesson. Remember that this is because the sortable data is not kept in the table itself, but in an associated array, which we will need later.

Now, using the same method as last time, we will grab the position of the clicked item, attempt the ajax call, but instead of changing a value, we will delete a row. Normally, deleting a row in ajax is very simple, you grab the row by the id, and do a hide() or slideUp(), etc. - but that will not totally work here. Sure it would function, but since we are using sizing and paging, they wouldn't reflect the changes: if you had 30 items in your table, and you were 'showing 10 of 30' items, and you deleted one the normal way, it would still say 'showing 10 of 30 items' when in fact, you are only now showing 9 of 29 items, and the problem then just compounds. The brilliant minds who wrote the dataTables plugin built in ways to get around this.

First thing, we get the position of the clicked item (which all have 'del_' as an id prefix) and store that:
var pos = oTable.fnGetPosition(this);

As well as the id of the cell as we need the corresponding 'person_id' that is contained there:
var del = $(this);

Then we simply call the .ajax() method in jQuery:
$.ajax({
    type: "POST",
    url: "ajax_functions/delete.aspx",
    data: "person_id=" + del.attr('id').replace('del_', ''),
    success: function() {
        $("#report").addClass("success").html("Person Deleted");
        oTable.fnDeleteRow(pos[0]);
    }
});

And that is where the magic happens. It was indicated that this was of type 'POST', the url that it is sent to (we will get to that in a moment), and the POST query that was sent (the delete cell's id, minus the 'del_' prefix). Then, on success, we simply output some feedback to the user into a new div with the id of 'report' - nothing special there. But on the next line, we use the 'oTable' that we stored earlier that has all of the sortable data, and call the included function 'fnDeleteRow' with the position that we collected earlier, and that is what deletes the row. The finished javascript looks like this:

delete.aspx
var oTable;
var aPos;
var editedCell;
$(function() {
    $("td[id^='del_']").addClass("pointer").click(function(event) {
        var pos = oTable.fnGetPosition(this);
        var del = $(this);
        $.ajax({
            type: "POST",
            url: "ajax_functions/delete.aspx",
            data: "person_id=" + del.attr('id').replace('del_', ''),
            success: function() {
                $("#report").addClass("success").html("Person Deleted");
                oTable.fnDeleteRow(pos[0]);
            }
        });
    });
    $(".editable").click(function() {
        aPos = oTable.fnGetPosition(this);
        editedCell = $(this);
    }).editInPlace({
        url: "ajax_functions/update.aspx",
        params: "ajax=yes",
        value_required: true,
        default_text: "click to edit",
        success: function() {
            var data = oTable.fnGetData(aPos[0]);
            data[aPos[1]] = editedCell.html();
        }
    });
    oTable = $("#sort_table").dataTable({
        "aoColumns": [null, null, null, { "bSortable": false}]
    });
});

backend

Lastly is the easy part, to make the backend to "ajax_functions/delete.aspx" to handle the POST.

ajax_functions/delete.aspx.cs
using System;
using System.Linq;

public partial class ajax_functions_delete : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        demoDataContext db = new demoDataContext();
        try
        {
            System.Threading.Thread.Sleep(1000);
            // get the person_id of the person being deleted
            int person_id = Convert.ToInt32(Request.Form[0]);
            db.persons.DeleteOnSubmit(db.persons.First(x => x.person_id == person_id));
            db.SubmitChanges();

            Response.Write("deleted");
        }
        // this will catch all the errors and output them to the edited field
        catch (Exception ex) { Response.Write("Error: " + ex.Message); }
    }
}

This code is pretty simple. Since we specified the POST in the ajax() call in jQuery, we knew the first element of the POST was going to be the person_id, and that is used to delete it from the DB.
*NOTE* that I used a Thread.Sleep() in there which I NEVER recommend using. it is just there to illustrate the ajax loading indicator that was implemented into the masterpage, which is covered next.

ajax loading indicator

I snuck a new div into the masterpage with the id of 'working' and bound it to all jQuery ajax events with the following js:
demo.master
$(function() {
    $("#working").bind("ajaxSend", function() {
        $(this).show();
    }).bind("ajaxComplete", function() {
        $(this).hide();
    });
});

Now any time jQuery is doing ajax, there will be a little notification so the user knows your app is not quitting on them. All other times, that div will be hidden.

Now all that we have left is the ability to add new items.

Inline editing with DB write : 'REAL' AJAX with Asp.Net Series

Writing to the database inline without a postback, simple and effective

This is a continuation of my 'REAL' AJAX with Asp.Net (not Asp.Net AJAX) series posts for those of us trying to stop relying on Asp.Net 'AJAX'.

This is the first example of ajax I am showing with a write to the DB, and this will show just how easy it really is. I am building on the last post (GridView Sorting/Paging : 'REAL' AJAX with Asp.Net Series) which will explain where/how the data and display is set up.

Also, you will notice that the CSS changed a bit, that is because this plugin has a hover property that resets the backgorund of the td, and that gave a funky interface; now this can be taken care of with some jQuery magic pretty easily, but that is outside the scope of what this is trying to show.

load all of your js

I am still using jQuery and the extension dataTables but for this lesson I am using an additional plugin: inPlace. So now our script loading looks like this (notice I moved the script refs into the masterpage in this lesson):

demo.master

<script type="text/javascript"
  src="js/jquery.js"></script>
<script type="text/javascript"
  src="js/jquery.dataTables.js"></script>
<script type="text/javascript"
  src="js/jquery.inplace.js"></script>


decide what you want to be editable

Now, since we are using our Repeater table from the last example, we just modify if ever-so-slightly to make it editable, to do that, we just add the class 'editable' (or whatever you want it to be) to each td that we want to be editable. In addition to adding a class, we are going to add meaningful ids to each of the cells, each ID will contain:
  • First 4 Letters - What field is being edited
  • Following digits - 'person_id' that is being edited

if you are unsure as to why we are doing this, keep reading, it will become clear.

inline_edit.aspx

<asp:Repeater ID="rpt" runat="server" DataSourceID="lds">
  <HeaderTemplate>
    <table id="sort_table">
      <thead>
        <tr><th>First</th><th>Last</th><th>Age</th></tr>
      </thead>
      <tbody>
  </HeaderTemplate>
  <ItemTemplate>
    <tr>
      <td id="frst<%#Eval("person_id")%>" class="editable">
        <%#Eval("first_name")%>
      
</td>
      <td id="last<%#Eval("person_id")%>" class="editable">
        <%#Eval("last_name")%>
      
</td>
      <td id="age_<%#Eval("person_id")%>" class="editable">
        <%#Eval("age")%>
      
</td>
    </tr>
  </ItemTemplate>
  <FooterTemplate>
    </tbody></table>
  </FooterTemplate>
</asp:Repeater>
<asp:LinqDataSource ID="lds" runat="server"
  ContextTypeName="demoDataContext" TableName="persons" />


make them editable

Now just add in a a little jQuery magic, and the fields will be editable:

inline_edit.aspx
$(function() {
    $("#sort_table").dataTable();
    $(".editable").editInPlace({
        url: "ajax_functions/update.aspx",
        params: "ajax=yes",
        value_required: true,
        default_text: "click to edit"
    });
});

You can look on the documentation for jquery.inplace.js for a further explanation, but what we declared there is that all items that have class 'editable' will now be editable; also, requests will get sent to 'ajax_functions/update.aspx' (which we haven't made yet) and we are requiring a value.

handling the ajax

Ok, so what is happening now, is if you click on a cell you will be able to edit it, and when you click off, or hit enter (you can edit these behaviors if you want), a POST will be sent to 'ajax_functions/update.aspx'. What is sent to the page is the following values:
  • update_value - the value you edited
  • element_id - the element id that was edited
  • original_html - value from before your edit

Now we only care about the first two in this example, but the third value could also be useful given the situation; possibly returning the old value if an error occurs? Also, it may be easier to see why we included both the field and the person_id in the ID of the <td>.

For handling, you could easily have seperate pages that only handle a certain element, i.e. ajax_functions/first_name.aspx for first_name, ajax_functions/last_name.aspx for last_name, etc. but I found that if you did it that way, you ended up writing the same code over and over - so what I did was combine it into a single update handling page. That is why I include 'what' is being updated in the id.

When you make your handling page, it is important that there is no html in it to start with - as the page text itself will be what is stuffed back into the area that you edited. This is the ENTIRE ajax_functions/update.aspx page:

ajax_functions/update.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="update.aspx.cs" Inherits=ajax_functions_update" %>


Anything we want to appear we will just dump out a Response.Write() for. Here is the handling code, I will explain afterwards:

ajax_functions/update.aspx.cs
using System;
using System.Configuration;
using System.Data.SqlClient;
using System.Linq;

public partial class ajax_functions_update : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        demoDataContext db = new demoDataContext();
        // this is unneccessary, but more efficient since there will 
        // be more than 1 db call, this uses the same connection
        SqlConnection con = new SqlConnection(
            ConfigurationManager
            .ConnectionStrings["demoConnectionString"].ConnectionString);

        try
        {
            // get the new value
            string newValue = Request.Form[0]; 
            // figure out what is being edited (remember, its the first 4 chars in the id)
            string what = Request.Form[1].Substring(0, 4);
            // get the person_id of the changing value (the remaining digits)
            int person_id = Convert.ToInt32(
                Request.Form[1].Substring(4, Request.Form[1].Length - 4));

            con.Open();
            // get the record you want to deal with
            person p = db.persons.First(x => x.person_id == person_id);

            // change the value depending on 'what' was sent
            switch (what)
            {
                case "frst": p.first_name = newValue; break;
                case "last": p.last_name = newValue; break;
                case "age_":
                    try { p.age = Convert.ToInt32(newValue); }
                    catch { throw new Exception("not an int"); }
                    break;
                default: throw new Exception("nothing saved");
            }
            db.SubmitChanges();
            con.Close();
            Response.Write(newValue);
        }
        // this will catch all the errors and output them to the edited field
        catch (Exception ex) { Response.Write("Error: " + ex.Message); }
        finally { con.Close(); }
    }
}

First off, the code simply sets the DataContext and opens a SqlConnection (it is explained why in the code). Then, we pull from the POST values from the Request. We pull 3 things from this:
  • person_id - 'person_id' that is being edited
  • what - what field is being edited
  • newValue - the new value for the update

Now is the easy part, get the 'person' to edit, run a switch on 'what' and and update it to 'newValue'. I caught all errors and output them to Response.Write() as that is all the user will be able to see. Also, whatever is written is returned so it integrated seamlessly.  What the user will see is 'Saving...' (unless you change the text or substitute an image) and when it is complete, they will see the new value in place of the old value (which is now written to the DB) as that is what was put in the Response.Write() (if there are no errors, otherwise they'll see the error message).

There you have it! A 'real' ajax inline update with asp.net, and it was as painless as can be! There are all sorts of other things you can do like apply a js function after the update has completed, add in a nice loading graphic instead of the text, etc. - fun to play around with.

Keep in mind with this, if a user (hacker) realizes how it works, they would be able to fabricate a POST to send to your page and update it how they see fit; so be sure you test, protect against that. In one of my apps that uses this. I make sure that the record being edited belongs to the user currently logged in before they can update.

Next will be deleting a row in this table with ajax.



but...

If I have 3 'people', with last names, 'a', 'b', and 'c', and edit 'b' to now be 'z', it will not sort correctly; 'z' will not be the last one in the table, it will still be 'c'. That is because the table data that does the sorting is not held within the table itself, but in an array of 'nodes'.

I left that as a seperate download because this part dives a little deeper into the relation of the sort/edit. What needs to be done is we have to go into the array that holds the nodes, and change the related data along with the represented data in the table.

how do I do that?

This one might require reading a few times, so bear with me. First you need to set the global variables we will be using:
var oTable;
var aPos;
var editedCell;

Then, you will need to store your table in memory:
oTable = $("#sort_table").dataTable();

Now you need to intercept the click in any editable field, and get the position of it in memory; also, we will store the edited cell into a variable as well:
$(".editable").click(function() {
    aPos = oTable.fnGetPosition(this);
    editedCell = $(this);
})

What is now in aPos is a 2-element array [int row_index, int cell_index]; editedCell is the cell that you just clicked. At this point we have all the necessary values to plug the data back in. So next we tack the '.editable()' on to the end of the previous 'click()' call and add a 'success' parameter that will fire on success of the edit. Here is the completed js:

inline_edit.aspx
var oTable;
var aPos;
var editedCell;
$(function() {
    $(".editable").click(function() {
        aPos = oTable.fnGetPosition(this);
        editedCell = $(this);
    }).editInPlace({
        url: "ajax_functions/update.aspx",
        params: "ajax=yes",
        value_required: true,
        default_text: "click to edit",
        success: function() {
            var data = oTable.fnGetData(aPos[0]); 
            data[aPos[1]] = editedCell.html();
        }
    });
    oTable = $("#sort_table").dataTable();
});

Now, the table will re-sort correctly, it's a little extra work, but the added benefit is worth it IMO. Here is the download with the extended functionality (it also has the next demo in it):

Shout it

GridView Sorting/Paging : 'REAL' AJAX with Asp.Net Series

Who knew this could be so easy... and FAST?

This is a continuation of my 'REAL' AJAX with Asp.Net (not Asp.Net AJAX) series posts for those of us trying to stop relying on Asp.Net 'AJAX'.

Ok, nothing too dramatic to start things off, we are going to make some tabled data sortable and pagable all without using a bit of postback. Not only that, but it is going to be incredibly easy!

First off we need the data that these demos will be working with, nothing complicated, just a simple SQL table 'person' that holds peoples' names and ages:

setup.sql
CREATE TABLE dbo.person (
person_id INT NOT NULL PRIMARY KEY IDENTITY,
first_name VARCHAR(50) NOT NULL,
last_name VARCHAR(50) NOT NULL,
age INT NOT NULL
);

Also included in the setup.sql file is some dummy data to populate it initially. We ill be using a Linq as our datasource throughout with a .dbml file named demo.dbml.

Next we need to display the data. Normally if I wanted to do paging, I would use a GridView, due to the fact is is already integrated. But that integration is sloooow, and requires a postback - we are ajax'ing here! What we are going to do will load all the data (which could be slower initially on large data sets) and use jQuery to take care of all of the lifting for us. So, it is much more efficient for us to use a Repeater. Without postbacks, all the advantages of a GridView quickly fade away. You will see how little markup you need:

sort_page.aspx

<asp:Repeater ID="rpt" runat="server" DataSourceID="lds">
  <HeaderTemplate>
    <table id="sort_table">
      <thead>
        <tr><th>First</th><th>Last</th><th>Age</th></tr>
      </thead>
      <tbody>
  </HeaderTemplate>
  <ItemTemplate>
    <tr>
      <td><%#Eval("first_name")%></td>
      <td><%#Eval("last_name")%></td>
      <td><%#Eval("age")%></td>
    </tr>
  </ItemTemplate>
  <FooterTemplate>
    </tbody></table>
  </FooterTemplate>
</asp:Repeater>
<asp:LinqDataSource ID="lds" runat="server"
  ContextTypeName="demoDataContext" TableName="persons" />


That is all the markup it takes, no code-behind. Now just call the javascript magic of the combination of jQuery and the extension dataTables:

sort_page.aspx
$(function() {
    $("#sort_table").dataTable();
});

And just like that you have a full sortable (with flipping sorting images), filterable, sizable, pageable and 'pretty' table using a simple Repeater. Now, I guess this isn't truly ajax, as nothing is truly pulled from the data store after the initial pull, but I argue that it is *relatively* because if you were to use a GridView jumping pages would cost a postback each time.

This is just the introduction here, but it is to show you how incredibly easy it is to get real, time-saving ajax and it is not as intmidating as you think. Next I will be showing you how to do inline editing of this table.

Shout it Update »

'REAL' AJAX with Asp.Net (not Asp.Net AJAX) Series : Building a complete ajax CRUD system with Asp.Net

Am I the only one who feels guilty every time I throw an 'UpdatePanel' into my code?

We all know Asp.Net AJAX is technically ajax, but it generally passes one the main advantage of using ajax in the first place.

Sure ajax is slick for user interface, but where I feel it really helps is speed. For example, if you want to edit a row in a GridView, you can easily do this using the GridView, stick it in an UpdatePanel and poof... you have an 'ajax' interface. But, and this is a huge but, the *ENTIRE* GridView was actually pulled from the DataSource, not just the row you were using. Asp.Net AJAX is a great tool, but it sort of masks (nearly) complete postbacks as being asynchronous; which is extremely convenient for quick development, but does not really help in the realm of performance.

Basically, I look at Asp.Net AJAX as a lazy way to do 'ajax' - that's in quotes as it really isn't asynchronous. So, lately, I have been making it my mission to get familiar with jQuery and integrating *real* ajax into my projects; and the speed gains are extremely noticable and quite impressive! Now jQuery is not necessary, but I am waaay to lazy and unskilled to write raw JS to do what I want, plus people have already written amazing jQuery plugins to do tons of what I want; not to mention it is probably written better than I could do anyway.

So, I am going to be posting a series of Asp.Net with 'real' ajax tutorials and examples in the coming weeks. I am going to be recreating all the functionality that you can get out of a GridView normally with edit, delete, new, sort, page etc. - a full CRUD (Create, Read, Update, Delete) system; but it will all be true ajax and very fast. Here are the topics that will be covered:
So stay tuned, I think you will be really impressed with how easy, and how much faster 'real' ajax is.

Shout it kick it on DotNetKicks.com

Making a registration system with Asp.Net and Linq-to-SQL (part 3)

Now that it's all up and working, we can make it friendlier and add some cool AJAX effects

After part 2 the system works just fine, but I wanted to take it a step further.This will be the last entry in this series, which I will follow up with a tutorial on how to retrieve passwords and log the registered users in.

what are we going to accomplish?

Like I said before, the system works, this is just the frosting on the cake, we are going to add some jquery and use the MasterPage to make this more accessible to the users.

markup

On the MasterPage, I added quite a few things, and on the registration page I added one key element:

demo.master
<h1>
  <span class="right">
    <a href="default.aspx">Home</a>
    <a href="register.aspx" class="triggerRegister">Register</a>
  </span>
  Registration Demo
</h1>

<div><asp:ContentPlaceHolder id="body" runat="server" /></div>

<div id="footer">
  <a href="default.aspx">Home</a> |
  <a href="register.aspx" class="triggerRegister">Register</a>
</div>

<div class="jqmWindow" id="register">
  <h3>
    <asp:UpdateProgress ID="uppRegister" runat="server">
      <ProgressTemplate>
        <div class="status">working...</div>
      </ProgressTemplate>
    </asp:UpdateProgress>
    <a href="#" class="x jqmClose">X</a>
    Register
  </h3>
  <cc:register ID="ccRegister" runat="server" />
</div>

register.aspx
cc:register ID="reg" runat="server" in_page="true" />

First of all, you have to realize, since the <div id="register" ... > has a CSS class of 'jqmWindow, it will not be visible when the page loads. This is because it is going to be within a modal popup window. Also, you will notice that there is a <cc:register ... > control within. That is what causes the small change to register.aspx as the attribute 'in_page' is added.What this does is elimiate errors that may occur if two or more of these controls are on a single page, so the validators only validate the controls they are pertinant to. The code is in the Utils.cs file if you would like to examine it.

I am also using an UpdatePanel within the modal so the user is able to see their feedback; if it wasn't (or something similar) used, the modal would be hidden after postback.

Also, some links with the class 'triggerRegister' are added, these will be the links that will trigger the modal popup (using jqModal) with the following JS:

demo.master
$('#register').jqm({ trigger: false }).jqmAddTrigger($('.triggerRegister'));

And just that simply we made the registration available multiple ways across the entire project! If the user has javascript turned off, it will will still work just fine as we have a 'backup' register.aspx page that will handle the request.Ahh the beauty of jQuery.


« Part 1« Part 2

Making a registration system with Asp.Net and Linq-to-SQL (part 2)

Verifiying your users' email and activating thier accounts

In part 1 of this tutorial, we ended by emailing the user a verification link. In this part, we will us that to verify the user and activate their account.

markup

The markup is very basic, as almost all of your stuff will be done in the backend:

confirm.aspx
<h2>Confirmation</h2>
<asp:Panel ID="Report" runat="server" />

Handle your input

This is where all the heavy lifting is done.Your user has a link which passes the verification guid in the querysting, so our verification page must parse the querystring.There are a few things we will be doing here:
  • Make sure there is a querystring
  • Make sure the Guid is in Guid format
  • Confirm the user from the DB based on Guid

Which is all reletively simple:

confirm.aspx.cs
if (string.IsNullOrEmpty(Request.QueryString["guid"]))
  throw new Exception("invalid inputs", new Exception("please navigate here from the provided link"));

SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["demoConnectionString"].ConnectionString);
try
{
  con.Open();
  dbDataContext db = new dbDataContext();
  string guid = Request.QueryString["guid"];
  Guid g = new Guid(guid);
  user u = Users.GetFromGuid(db, g);
  if (u.confirmed)
    Report.Success("account already confirmed", "apparently it was fun enough to do twice...");
  else
  {
    u.confirmed = true;
    db.SubmitChanges();
    Report.Success("account confirmed", "put some link here for the user to continue");
  }
}
catch (Exception ex)
{
  if (ex.Message.Contains("no elements"))
    ex = new Exception("confirmation number not found");   Report.Error(ex);
}
finally { con.Close(); }

Users.cs
public static user GetFromGuid(dbDataContext db, Guid guid)
{ return db.users.Single(u => u.guid_ == guid); }

Ok, now what was done there? First, we simply test to see if a proper querystrirng was passed, if not, it throws an error which is handled with my.Error() extension.Then it goes on to make a SqlConnection, which might seems strange as it is not necessary, *but* since we are possibly making two calls to the DB: getting the user and confirming the user (if necessary) - opening the connection will make sure it only opens once as opposed to twice if we weren't to open it; it is unnecessary, but it is ever-so-slightly more efficient.After that it goes to get the user object from the DB by the GUID, if it is found, it is then confirmed.If there are eny errors or it is not found, it is handled.

Now, since nothing is emailed or anything like that, we can assume (maybe not totally safely) that the user who confirms is the one who got the email. I suppose there could be a brute force GUID bombing of the site, but that would be incredibly inefficient, not to mention pointless as it would only activate accounts and not provide the hacker with anything.

And that is it. You now have a fully working registration system that requires email confirmation and it wasn't even that tough. Here is the code:


« Part 1» Part 2

Making a registration system with Asp.Net and Linq-to-SQL (part 1)

This registration has a slick interface and user verification

NOTE* I do not cover encryption in this tutorial, but I highly discourage storing plain-text passwords in your DB!

It is inevitable that every programmer will want to eventually make a site which requires registration. Then you need to deal with spam accounts and all that good stuff. This is part one of a series of tutorials, where I will show you how to set up a registration process that requires a valid email address. I will be building on the code provided here for the next tutorial and so on. In the future, I will also include a login process I developed that will lock out accounts after a certain amount of attempts, retrieve passwords, and all sorts of other goodies. But before users can log in, they have to register.

I will be using a lot of other people's stuff in this example, such as jQuery, jQuery extensions, Grid960 and so on as well as a lot of my own Extensions, etc. With that said, this is going to have a lot of 'extras' included such as Ajax functionality and some UI niceties to make it a quality interface - you can feel free to cut these parts out, but I feel it will be nice for those that want it. All of the code referenced is included.

Storage

The first step is setting up your user table in the database. The most important thing to think of here is: what am I going to need to collect? I am all about being as simple as possible, so I am going to require two things: email and password - that is it. This is what I came up with:
  • userid - the primary key integer
  • email - the user's email
  • password - user's password
  • guid - guid for verification
  • created - date created; both for record keeping and to see if it was not confirmed after a long time it can be removed
  • confirmed - whether or not it is confirmed
  • last try* - the last login
  • number of failed logins* - number of failures for lockout

The two starred items will not really be used in this too tutorial and are optional if you do not want to prevent unlimited login attempts; though they will be relevant in upcoming tutorials.

Here is the SQL to create my table for users:
CREATE TABLE dbo.users (
userid INT NOT NULL PRIMARY KEY IDENTITY,
email VARCHAR(100) NOT NULL UNIQUE,
password_ VARCHAR(30) NOT NULL,
guid_ UNIQUEIDENTIFIER NOT NULL UNIQUE,
created DATETIME NOT NULL,
confirmed BIT NOT NULL DEFAULT 0,
last_try DATETIME NOT NULL,
tries INT NOT NULL DEFAULT 0
);

Markup

Now that we have our table, go ahead and drag it into a dbml - for this example, I will use one named db.dbml. Now we have our access layer built, we can work on making a registration control; I will be making an ascx registration control, so it can be plugged in aywhere I want to use it. Since I am only collecting two bits of information, this will be a simple control. Here is the markup, I will explain it afterwards:

register.ascx
<asp:UpdatePanel ID="upContact" runat="server">
  <ContentTemplate>
    <div class="pad">
      <asp:Panel ID="Report runat="server" />
      <asp:Panel ID="pnlRegister" runat="server" DefaultButton="registerSubmit">
        <div class="pad_sides">
          <div>
            <h4>
              <asp:RequiredFieldValidator ID="rfvRegisterEmail" runat="server" CssClass="validate" ValidationGroup="register"
                ControlToValidate="registerEmail" ErrorMessage="required" Display="Dynamic" />
            <asp:RegularExpressionValidator ID="regRegisterEmail" runat="server" ControlToValidate="registerEmail"
                ErrorMessage="invalid email" CssClass="validate" Display="Dynamic" ValidationGroup="register"
                ValidationExpression="^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$"
            />
              email
            </h4>
            <asp:TextBox ID="registerEmail" runat="server" CssClass="inputBig full" />
          </div>
        <div>
          <h4>
            <asp:RequiredFieldValidator ID="rfvRegisterPassword" runat="server" CssClass="validate" ValidationGroup="register"
                ControlToValidate="registerPassword" ErrorMessage="required" Display="Dynamic" InitialValue="8 character minimum" />
            <asp:RegularExpressionValidator ID="regRegisterPassword" runat="server" CssClass="validate" ValidationGroup="register"
              ControlToValidate="registerPassword" ErrorMessage="must be at least 8 characters" Display="Dynamic"
              ValidationExpression="^.{8}.*$" />
            password
          </h4>
          <asp:TextBox ID="registerPassword" runat="server" CssClass="inputBig full wm watermark" Text="8 character minimum" />
        </div>
        <div class="summary field">
          <asp:LinkButton ID="registerSubmit" CssClass="button"
            Text="submit" runat="server" ValidationGroup="register" onclick="registerSubmit_Click" />
          </div>
        </div>
      </asp:Panel>
    </div>
  </ContentTemplate>
</asp:UpdatePanel>

Ok, there is a lot going on here, so I will go part by part.

First of all, you will notice that it is within a Asp.Net UpdatePanel which I have been trying to get away from for most things, but for such small controls I have found that is is the best way to go about it: easy and fast.

Next you will see that I have added a Panel with an ID of "Report" - I use this as a standard in most applications as to where to output my 'updates' to the user. This is explained here. The code for this is included in the Extensions.cs file.

Next there is a good amount of validation going on.
  • First I use RequiredFieldValidators for both fields
  • Then I added the RegularExpressionValidator for emails
  • Then I added the RegularExpressionValidator for password length
  • Finally you will notice that the password entry has a watermark which is called via jQuery in the MasterPage

You might notice that I am not using a password field or asking for password verification. This is something you might want to do, but for this example, security is not really a concern, simplicity is; so I figure if you can see your password, you wont screw it up. Also, since we will be adding a password retrieval function, this won't be a big deal.

Backend

That is the markup, but now we have to go to the code so it actually does something. Now what does this have to accomplish?
  • Check if the Email has already been registered
  • Create a new entry in the users table
  • Send an email with a verification link

Not too much going on here, here is the code for accomplishing that, followed by an explanation:

register.ascx.cs
using System;

public partial class controls_register : System.Web.UI.UserControl
{
  protected void Page_Load(object sender, EventArgs e)
  {
    if (this.Attributes["in_page"] != null)
    {
      Utils.DuplicateValidators(this);
    }
  }

  protected void registerSubmit_Click(object sender, EventArgs e)
  {
    try
    {
      dbDataContext db = new dbDataContext();
      if(Users.DuplicateEmail(db, registerEmail.Text))
        throw new Exception("email already registered");
      Guid g = Guid.NewGuid();
      user u = new user()
      {
        created = DateTime.Now,
        email = registerEmail.Text,
        guid_ = g,
        password_ = registerPassword.Text,
        last_try=DateTime.Now
      };
      db.users.InsertOnSubmit(u);
      db.SubmitChanges();
      Email email = new Email(registerEmail.Text, Settings.Get("gm"),
        "please verify your email address",
        "http://yoursite.com/confirm.aspx?guid=" + g.ToString()); //we will get to this in the next tutorial
      email.Send();
      Report.Success("account successfully created", "please check your email to verify your account");
      pnlRegister.Visible = false;
    }
      catch (Exception ex)
    {
      Report.Error(ex);
    }
  }
}

The first thing that happens here is the check for if the Attribute "in_page" is set. This is a bit of a sidebar as it just takes care of duplicate validators if there is more than one of these controls on the page, since I plan on showing how to use them both as a modal popup as well as a standalone page I had to add this check; that way, if you are filling out the popup instead of the form on the page it makes sure that it will not fire the validation for the form you are not using, all it does is change the validation group. The code is visible in the Utils class if you are curious about it. Don't really worry about this too much right now, as it will be covered in an upcoming tutorial.

Next it checks if the email is a duplicate. This calls the Users.cs class, we will get to that next; just remember for now it returns true if it is already in the system, false if not.

If it is new, a new user is then made and inserted into the DB via Linq-to-SQL.

An email is made and sent to the user with the link to the authorization page (which will be coevered in the next tutorial). This is sent using a simplified Email class. The authorization is the guid which was produced - I will cover the authorization page in the next part of the tutorial.

Then the user is notified of the status whether it is success or error using the panel reporting extensions.

This is all pretty simple, all that is left is to explain what is going on in the Users.cs class which is also simple:

Users.cs
using System.Linq;

public static class Users
{
  public static user GetFromEmail(dbDataContext db, string email)
  { return db.users.First(u => u.email.ToLower().Equals(email.ToLower())); }

  public static bool DuplicateEmail(dbDataContext db, string email)
  {
    try
    {
      user temp = GetFromEmail(db, email);
      span class="var">return true;
    }
    catch { return false; }
  }
}

As you can see, this is just two basic LINQ queries, the first one retrieving a user object based on an email string. And the duplicate check which tries to find a user with the given email, if it can, it will return true, meaning it is already in there, otherwise it spits out a false.

And that is all there is to it so far. It is not yet a working system as the user has not verified their identity, but we have accomplished the base of a registration system:
  • Collected the user's email address
  • Collected their password
  • Produced a unique Guid for verification
  • Sent them an email to verify their identity

Now we have it all built, we just need to display everything and call the necessary scripts. I am going to stick all of these pages within a masterpage which calls the scripts in the Page_Load:

demo.master.cs
protected void Page_Load(object sender, EventArgs e)
{
  Page.ClientScript.RegisterClientScriptInclude(typeof(demo), "jQuery", ResolveUrl("~/js/jquery.js"));
  //this will be used in the next tutorial
  Page.ClientScript.RegisterClientScriptInclude(typeof(demo), "jQuery", ResolveUrl("~/js/jqModal.js"));
}

Then just call the control (registered in the web.config file) and the js in the markup:

register.aspx
<h2>Registration</h2>
<cc:register id="reg" runat="server" />

and call the watermark frorm jQuery:

demo.master
<script type="text/javascript" language="javascript">
   $().ready(function() {
     swapValues = [];
     $(".wm").each(function(i) {
       swapValues[i] = $(this).val();
       $(this).focus(function() {
         if ($(this).val() == swapValues[i]) {
           $(this).val("").removeClass("watermark")
         }
       })
     })
   });
</script>

Notice that I am calling the watermark in the masterpage. This may seem strange, but this stops me from writing redundant code as this will take care of *all* watermarks that I will put into this project due to the versatiliy of jQuery.

All we have to do to complete this registration process is to verify the email which will be the next part to this tutorial. I am also going to show how to add this into a registration popup. The hard part is all finished.


Shout it » Part 2 » Part 3