Web Development

MVC5: DropdownlistFor: How to handle empty data

5-Nov-14 5:15

You need to ask a specific question.

There are only 10 types of people in the world, those who understand binary and those who don't.

Re: website

Dominic Burford7-Nov-14 4:57

Dominic Burford

7-Nov-14 4:57

Have a go at developing the website yourself using whatever technology you are familiar with, and when you get stuck, then post a specific question here.

"There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare

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NarVish4-Nov-14 23:26

NarVish

4-Nov-14 23:26

Hi,

I created dropdownlist in my view and controller as below. If ViewBag.CategoryList is null, it is throwing exception. how to handle the exception. Please guide me. Thank you.

HTML

<div class="span3">@Html.DropDownListFor(m => m.Category, (IEnumerable<SelectListItem>)ViewBag.CategoryList)</div>

Code is:

DataTable dt = registrationDAO.GetParameters("PSTND");

List<SelectListItem> positions = new List<SelectListItem>();
foreach (DataRow dr in dt.Rows)
{
     positions.Add(new SelectListItem { Text = dr["PARAM_VALUE"].ToString() });
}
ViewBag.CategoryList = positions;

MVC 4.5 Noobie Question

Kevin Marois3-Nov-14 19:21

Re: MVC 4.5 Noobie Question

3-Nov-14 19:21

I have a question about validation. I'm a long time Windows developer, and I'm diving into MVC 4.5 now.

Until now I have purposely avoided using error validation attributes because validation doesn't belong in the UI - it belongs in the BL - Where business rules are supposed to be enforced. Requiring a Customer Entity to have a Customer Name is a RULE, so it's validation belongs in the BL.

But a lot of the MVC examples I see have this type of data entry validation in the MVC project's models. It just doesn't sit well with me because you're then forced to maintain validation (AKA business rules) in two places - the UI AND the BL.

When the business rules change (not IF) then you now must recompile TWO layers of the app, not just the BL.

I'm curious what you experienced MVC people have to say on this.

Thanks

If it's not broken, fix it until it is

Matt U.4-Nov-14 6:53

Matt U.

4-Nov-14 6:53

I'm not an MVC expert, but I'm diving into it with my employer. I've come across this article[^] and I believe it may be what you're looking for. The validation can be done in the service layer, which can be a separate component, if I'm not mistaken.

djj55: Nice but may have a permission problem
Pete O'Hanlon: He has my permission to run it.

Re: MVC 4.5 Noobie Question

Anurag Gandhi30-Nov-14 23:01

Anurag Gandhi

30-Nov-14 23:01

Hi,
I have been working with MVC since last 4+ yrs.
I not a big fan of Data Annotations and attributes for everything. (It is really cool in many cases but not al least for validations.)

For validations, I use JQuery validations and NOT data annotations.
MVC do not force you to use attributes for validations and you can always avoid it.
JQuery has many good libraries for all kind of validations.

Life is a computer program and everyone is the programmer of his own life.

THE IMAGE IS NOT DISPLAY CROOS MARK APPEARS ON WEBPAGE

Member 112021843-Nov-14 19:07

Member 11202184

3-Nov-14 19:07

CODE IN .ASPX.CS FILE :

XML

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text;
using System.Drawing;
using System.IO;




public partial class Main_frmIndex : System.Web.UI.Page
{
    CommonBL BL = new CommonBL();
    protected void Page_Load(object sender, EventArgs e)
    {
        AssignData();
    }

    private void AssignData()
    {
        DataSet ds = new DataSet();
        ds = BL.GetDataSet("Select top 2 id,Product_Category,Category_id,Prd_Name,Prd_Pack,Prd_Details,Prd_Indication,PackImage,ProductLogo,pId from tbl_Products Inner join tbl_CategoryMaster On tbl_Products.Category_id = tbl_CategoryMaster.pId where tbl_Products.Active= 1 and tbl_Products.DeletedFlag =0 and tbl_CategoryMaster.Active= 1 and tbl_CategoryMaster.DeletedFlag =0 order by tbl_Products.UpdatedDate desc");
        StringBuilder strShow = new StringBuilder();
        strShow = strShow.AppendLine("<table width='100%' border='0' cellspacing='0' cellpadding='0'><tr>");

        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
        {
            if (i == 0)
            {
                strShow = strShow.AppendLine("<td width='50%' class='rightline'  valign='top' align='left'>");
            }
            else
            {
                strShow = strShow.AppendLine("<td width='50%' valign='top' align='left' class='padl10'>");
            }
            strShow = strShow.AppendLine("<table border='0' width='100%' cellpadding='0' cellspacing='0'>");
            strShow = strShow.AppendLine("<tr><td class='subheader vat padt10'>" + ds.Tables[0].Rows[i]["Product_Category"] + "</td></tr>");
            strShow = strShow.AppendLine("<tr><td class='padt10'><img src='../Uploads/Products/" + ds.Tables[0].Rows[i]["PackImage"] + "' width='124' height='114' alt='' /></td></tr>");
            //strShow = strShow.AppendLine("<tr><td>" + ds.Tables[0].Rows[i]["Prd_Name"] + "<br/>" + ds.Tables[0].Rows[i]["Prd_Details"] + "<br/></td></tr>");
            strShow = strShow.AppendLine("<tr><td>" + ds.Tables[0].Rows[i]["Prd_Name"] + "</td></tr>");
            strShow = strShow.AppendLine("<tr><td class='padr5 padb15'><a class='more' href='../Main/frmProductDetails.aspx?id=" + ds.Tables[0].Rows[i]["Id"].ToString() + "'>more...</a></td></tr></table></td>");
        }
        strShow.AppendLine("</tr></table>");


        lblShow.InnerHtml = strShow.ToString();
    }
}

Re: THE IMAGE IS NOT DISPLAY CROOS MARK APPEARS ON WEBPAGE

Richard MacCutchan3-Nov-14 21:29

Richard MacCutchan

3-Nov-14 21:29

Please do not repost, you already asked this question at private void AssignData()[^].

Re: THE IMAGE IS NOT DISPLAY CROOS MARK APPEARS ON WEBPAGE

ZurdoDev4-Nov-14 8:21

4-Nov-14 8:21

As mentioned before, all you have to do is view the source of the generated page and you'll see exactly what is happening and then you can fix it.

There are only 10 types of people in the world, those who understand binary and those who don't.

CSS Problem

Kevin Marois3-Nov-14 10:41

3-Nov-14 10:41

I'm following an example from a book, and it has this simple css sheet:

body {

    .field-validation-error     {color:#f00;}
    .field-validation-valid     {display:none;}
    .input-validation-error     {border:1px solid #f00; background-color: #fee}
    .validation-summary-errors   {font-weight: bold; color #f00;}
    .validation-summary-valid    {display: none;}
}

On the first line, the field-validation-error, if I hover over the starting period, I see the error

"Missing a property name before the colon "(':')" in the "(property) : (value)" declaration"

There's also a squiggly at the end of the line that shows

The block is unclosed; '{' expected

If I remove the line, then the next line gives the same errors.

What am I doing wrong here?

If it's not broken, fix it until it is

modified 3-Nov-14 16:59pm.

Richard Deeming3-Nov-14 11:30

Richard Deeming

3-Nov-14 11:30

That's not a very good book - you can't nest rules like that. Remove the body { ... }:

CSS

.field-validation-error     {color:#f00;}
.field-validation-valid     {display:none;}
.input-validation-error     {border:1px solid #f00; background-color: #fee}
.validation-summary-errors   {font-weight: bold; color #f00;}
.validation-summary-valid    {display: none;}

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois3-Nov-14 11:49

3-Nov-14 11:49

That did it.

Thanks

If it's not broken, fix it until it is

Kornfeld Eliyahu Peter3-Nov-14 21:10

Kornfeld Eliyahu Peter

3-Nov-14 21:10

That IS a good book, but the sample isn't for CSS but LESS!

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)
תפסיק לספר לה' כמה הצרות שלך גדולות, תספר לצרות שלך כמה ה' גדול!

ASP.Net MVC 5 - First Project Error

Richard Deeming3-Nov-14 23:19

Richard Deeming

3-Nov-14 23:19

If it was a good book, it should have made it more obvious that the example wasn't pure CSS. Roll eyes | :rolleyes:

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois3-Nov-14 5:51

Re: ASP.Net MVC 5 - First Project Error

3-Nov-14 5:51

I am brand new to web development. I bought this book[^].

I just started into it, and I followed the instructions exactly. So far I understand, then I hit a bug.

I got to the part where I add the first view. I added it and ran the app and got this message in the browser:

Line 22:     using System.Web.WebPages;
Line 23:     using System.Web.Mvc;
Line 24:     using System.Web.Mvc.Ajax;                 <==== ERROR HERE IN RED
Line 25:     using System.Web.Mvc.Html;
Line 26:     using System.Web.Routing;

I searched the solution and this only appears in the Web.Config. If I remove it then it errors on the next line.

It appears that Ajax and Html are both in System.Web.Mvc, and I have a reference to it in my project.

I really have no clue what I'm doing so far. Can someone point me in the right direction?

Thanks

If it's not broken, fix it until it is

Kevin Marois3-Nov-14 6:02

Handlings rows in Datatables

3-Nov-14 6:02

Fixed. See this[^]

If it's not broken, fix it until it is

adekunbi29-Oct-14 3:43

29-Oct-14 3:43

Hi All. Please I am in dire need of help with jeditable and datatables.

I have some datatables that are populated via ajax call. They are well populated and the editable part works to an extent. However, I have three major challenges.

1. If I try to add a new row to my table, it gives me an error, but it is actually saved to the database, so if I refresh of the table, it is populated with the data
2. I have a button in the row of my datatables, on click of this button, I want to get the values in the row, but I am unable to get it. it gives me an an "undefined" output. Pls note that this table has child row that is also being populated by ajax.
3. I have some select buttons in my jEditable plugin, they are also populated via ajax, however I want each option to have a unique ID. The problem is, how to configure its json data to look like what it accepts.
Thank

Kunbi

ZurdoDev29-Oct-14 5:46

29-Oct-14 5:46

You'll have to give specific information before anyone can help you.

There are only 10 types of people in the world, those who understand binary and those who don't.

adekunbi29-Oct-14 6:01

29-Oct-14 6:01

Thank you for even having a look at it. I am not sure of what you mean by specific information, but I have a jsfiddle account where you can find the code. Although I cant't populate it with actual data but you can have an idea of what's going on. The links are Question 2 http://jsfiddle.net/aadewojo/751ry6pa/ and Question 3 http://jsfiddle.net/aadewojo/pext0hm9/.
Thanks and I look forward to your reply.

ZurdoDev29-Oct-14 6:04

29-Oct-14 6:04

For starters, you mentioned you get an error on #1. You need to realize we can't see what you're doing so provide us with the error and show us where it goes wrong.

You have debugged this right?

There are only 10 types of people in the world, those who understand binary and those who don't.

adekunbi29-Oct-14 23:40

29-Oct-14 23:40

The first jsfiddle works for question 1 and 2. Thanks.

ZurdoDev30-Oct-14 1:37

30-Oct-14 1:37

All I see are some column headings. No buttons. What am I supposed to see or do?

There are only 10 types of people in the world, those who understand binary and those who don't.

adekunbi30-Oct-14 1:41