Make values in a foreach loop default to something

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Okay so, I have a foreach loop and its returning values of the model it goes through as null... I dont want to have to go to each individual row and say if the value is null leave it blank... I was wondering if there is a faster solution to this. This is a problem that I am having multiple areas...

Here is what my foreach loop looks like....

HTML

@foreach (var item in Model)
{
    <tr>

        <td>
            <div class="btn-group btn-group-sm btn-group-solid">
                <a href="@Url.Action("OverviewDetails","PrototypeOverview",new { id= item.prototype_id})" class="btn btn-default"><i class="fa fa-eye"></i></a>
                <a href="#" class="btn btn-default"><i class="fa fa-file"></i></a>
            </div>
        </td>
        <td>@item.prototype_number</td>

        <td>@item.prototype_category.prototype_category_name</td>

        <td>@item.prototype_sub_category</td>

        <td>@item.season</td>
        <td>@item.garment_quantity</td>
        <td>@item.garment_size</td>
        <td>@item.for_reason</td>

        <td>
            @item.purpose.
        </td>

        <td>@item.fit</td>  @*is this correct*@
        <td>@item.style_construction_reference</td>
        <td>@item.approval_code</td>
        <td>@item.is_handsand</td>
        <td>@item.prototype_handsand_pattern</td>
        <td>@item.is_lazer</td>
        <td>@item.prototype_lazer_pattern</td>
        <td>@item.is_pp_spray</td>
        <td>@item.finish_name</td>
        <td>@item.number_of_washes</td>
        <td>@item.wash_code</td>
        <td>@item.is_filler</td>
        <td>@item.is_stamp</td>
        <td>@item.prototype_description</td>
        <td>@item.group_search_name</td>
        <td>@item.request_date</td>
        <td>Pattern Work Required</td>
        <td>@item.need_by_date</td>
        <td>Sew Work Required</td>
        <td>@item.scheduled_date</td>
        <td>Stage Status</td>
        <td>@item.initiatorUser.full_name</td>
        <td>@item.initiatorUser.PhoneNumber</td>
        <td>@item.workgroup.workgroup_name</td>
        <td>@item.pattern_number</td>
        <td>@item.marker_name</td>
        <td>Embroidery (y/n)</td>
        <td>Body Fabric Vendor</td>
        <td>Body Fabric Vendor Style #</td>
        <td>Body Fabric Weight</td>
        <td>Body Fabric Content</td>
        <td>@item.prototype_fabric_information_sap_code</td>
        <td>@item.washEngineerUser.full_name</td>
        <td>@item.washEngineerUser.PhoneNumber</td>
        <td>@item.is_prelines</td>
        <td>@item.cut_number</td>
        <td>Target</td>
        <td>@item.sub_business_unit.sub_business_unit_name</td>
        <td>@item.buyer.buyer_name</td>
        <td>@item.cost_center.cost_center_number</td>
        <td>@item.remake_reason</td>



        @*<td>@item.sub</td>*@
    </tr>

}

What I have tried:

I have tried to put a condition on each of the individual rows... to check for a null and if its a null i kept the <table><tbody><tr><td></td></tr></tbody></table> blank. This is a very time consuming task and im looking for a faster solution... I have tables that have over 50 columns sometimes and writing that over and over is quite annoying...

Posted 8-Apr-16 11:46am

Member 12362975

Updated 8-Apr-16 18:40pm

Matt T Heffron

v2

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Member 12362975 8-Apr-16 17:47pm

This is the foreach loop.... it wouldnt paste in original post

@foreach (var item in Model)
{
<tr>

<td>
<div class="btn-group btn-group-sm btn-group-solid">

</div>
</td>
<td>@item.prototype_number</td>

<td>@item.prototype_category.prototype_category_name</td>

<td>@item.prototype_sub_category</td>

<td>@item.season</td>
<td>@item.garment_quantity</td>
<td>@item.garment_size</td>
<td>@item.for_reason</td>

<td>
@item.purpose.
</td>

<td>@item.fit</td> @*is this correct*@
<td>@item.style_construction_reference</td>
<td>@item.approval_code</td>
<td>@item.is_handsand</td>
<td>@item.prototype_handsand_pattern</td>
<td>@item.is_lazer</td>
<td>@item.prototype_lazer_pattern</td>
<td>@item.is_pp_spray</td>
<td>@item.finish_name</td>
<td>@item.number_of_washes</td>
<td>@item.wash_code</td>
<td>@item.is_filler</td>
<td>@item.is_stamp</td>
<td>@item.prototype_description</td>
<td>@item.group_search_name</td>
<td>@item.request_date</td>
<td>Pattern Work Required</td>
<td>@item.need_by_date</td>
<td>Sew Work Required</td>
<td>@item.scheduled_date</td>
<td>Stage Status</td>
<td>@item.initiatorUser.full_name</td>
<td>@item.initiatorUser.PhoneNumber</td>
<td>@item.workgroup.workgroup_name</td>
<td>@item.pattern_number</td>
<td>@item.marker_name</td>
<td>Embroidery (y/n)</td>
<td>Body Fabric Vendor</td>
<td>Body Fabric Vendor Style #</td>
<td>Body Fabric Weight</td>
<td>Body Fabric Content</td>
<td>@item.prototype_fabric_information_sap_code</td>
<td>@item.washEngineerUser.full_name</td>
<td>@item.washEngineerUser.PhoneNumber</td>
<td>@item.is_prelines</td>
<td>@item.cut_number</td>
<td>Target</td>
<td>

Sergey Alexandrovich Kryukov 8-Apr-16 17:56pm

All your <td> <tr> are not statement. You need to grasp the idea of programming: never repeat anything.
—SA

Member 12362975 8-Apr-16 17:58pm

what? this doesnt make sense??english would be appreciated. I know all of <td> are not using model... I know i typed out values for some... mainly because those values are not available to retrieve just yet....

Sergey Alexandrovich Kryukov 8-Apr-16 21:59pm

Oh, sorry. Yes, it's a good idea to use English. :-)
Well, I clarified some of it in my comment below. I also meant that your quite reasonable "I don't want to have to go to each individual row and say..." still assume that it's an option, even if it's bad. But programming is the field where it's rejected from the very beginning. Adding some Razor syntax with C# code should be considered as a convenient ad-hoc technique, where you customize/parametrize generation of HTML in a HTTP response by injecting some server-side generated code in some elements. But should you repeat some elements, (<p>, <td>, <tr) even a small number of times, this ad-hoc, way too manual technique should be rejected. One solution would be to generate the whole fragment of HTML solely in C#, not interlacing C# and HTML code...
—SA

Matt T Heffron 8-Apr-16 19:22pm

Sergey, this looks like valid ASP.NET syntax (for the part of interest).
(And I fixed the markup...)
(No, I'm not any kind of ASP.NET guru. I just had a suspicion! ;-) )

Sergey Alexandrovich Kryukov 8-Apr-16 21:50pm

How? This is Razor syntax:

@foreach (var item in Model) { /* ... */ }

or

@{ /* ... */ }

In both cases, what can be inside { } loops, what's shown as /* ... */ comments? This is C# code. C# fragment of code is not finished until less nested } It should be C# code, not <td> or <tr>. Maybe the inquirer meant it in metaphorical sense...

And it does not help the idea. A lot of <td>, that's it. One solution is just to auto-generated the whole fragment of HTML code...

—SA

Matt T Heffron 8-Apr-16 21:59pm

In my defense, I said "this looks like valid ASP.NET..."

Sergey Alexandrovich Kryukov 8-Apr-16 22:07pm

Sure, I understand. I am not an expert in it, too, but I can read on the syntax and follow simple logic; and I tried out Razor before, it looks quite logical and reasonable, no mystery behind it. The programming model is basically very simple...
—SA

Dave Kreskowiak 8-Apr-16 20:02pm

What do you mean by "it takes too long"? Are you building a table that has thousands of rows in it? There's no if statement in the code you posted.

Or are you complaining that it takes to long to write 50 seperate TD tags with the field you want? This is easily solved. Don't show 50 freakin' columns! unless each of these is only a few characters wide and displayed in a small font, you can't fit 50 columns on the screen anyway so why show them? Left the user filter the data they want.

Member 12362975 9-Apr-16 0:58am

i personally think its stupid to have 50 columns but its a requirement... we use a thing called data tables....

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andres_fprado · Answer 1 · 2016-04-08T18:40:00

Solution 1

Instead of adding "ifs" to each line, you could try to use the null coalescing operator "??" (which internally involves an if statement, but is much more elegant and readable). The format would be (I take just one line as an example):

HTML

<table><tbody><tr><td>@item.prototype_category.prototype_category_name ?? ""</td></tr></tbody></table>

Of course, I'm assuming the data type of prototype_category_name is a string, otherwise you will have an error. This will replace a null value with an empty string, which will just leave an empty cell. Of course, you might want to replace the empty string with something else to indicate that the cell is empty...

--AFP

Posted 8-Apr-16 18:40pm

andres_fprado

Comments

Member 12362975 9-Apr-16 0:49am

so how would i do <td>@item.prototypecategory.prototype_category_name ?? </td>

and have the <td></td> empty if the value is empty? i mean where do i basically say if it is null then make it an empty <td>? It is part of requirements to make it empty.

andres_fprado 9-Apr-16 0:54am

In Razor, what you enter after the "@" must be a valid C# expression. In this case, I'm proposing you use the "??" operator. This is a binary operator, which translates essentially as:

x = a ?? b

is equivalent to

if(a != null)
x = a;
else
x = b;

Therefore, you must have a valid C# expression after the ?? operator. For example, if you want the <td></td> to empty, you would put ?? "" after the expression you are evaluating (which means, 'if the expression is null, replace with an empty string).

Member 12362975 9-Apr-16 0:56am

so something like this?

<td>@item.prototypecategory.prototype_category_name ?? "" <td></td></td>

andres_fprado 9-Apr-16 0:59am

No, you don't need the second <td></td> at all. You would just write:

<td>@item.prototypecategory.prototype_category_name ?? "" </td>

In Razor, the first <td> will always be emitted (written to the output). Then, the @ means to evaluate the C# expression and emit the result (which will be either the value of your variable, if not null, or an empty string otherwise). Finally, the closing </td> will always be emitted.

So, if the variable's value was "test", you would get <td>test</td>, and if it was null, you would simply get <td></td>.

Member 12362975 9-Apr-16 1:03am

so then how would the expression be if have a value other than a blank <td>?

for instance lets say the value that the item is null. since it is null i want a <td>no</td> to be displayed on the screen?

andres_fprado 9-Apr-16 1:05am

You could do that with:

<td>@item.prototypecategory.prototype_category_name ?? "no" </td>

Member 12362975 9-Apr-16 1:06am

interesting. i have some reading to do. thanks alot this sounds like a solid lead :D. if it pans out ill accept the solution.

andres_fprado 9-Apr-16 1:10am

Good luck! This is a little understood (and quite useful) operator in C#. I've used it in similar situations as the one you described. Hope it helps.

Member 12362975 9-Apr-16 1:15am

final question...
what would i do if the object...prototypecategory is null? so in that razor statement... im going through the prototype category object to retrieve the the category name. What if both the name and the category were null. is there a expression to handle that?

currently what i have for a situation like that is....this is for a prototype purpose. similar to a prototype categories, but a different object and table...

also im not a 100% sure if im using object in the correct syntax here when i say it.

@if (item.purpose == null)
{
<td></td>
}
else
{
if (item.purpose.prototype_purpose_name != null)
{
<td>@item.purpose.prototype_purpose_name</td>
}
else
{
<td></td>
}
}

andres_fprado 9-Apr-16 1:18am

Try with:
<td>@(item.purpose == null) ? "" : (item.purpose.protype_purpose_name ?? "")</td>

Member 12362975 9-Apr-16 10:11am

this one did not work. it shows the value as true... this is what shows up...on the webpage from that expression.

True ? "" : (item.purpose.prototype_purpose_name ?? "")