Which one to use
<label>Name</label>
<asp:Label Text="Name" runat="server"></asp:Label>
Genreally we are using label to show some text only(like not to many business logic on lables).
As a perfomance point of view which one to use.
There would be very little to gain in performance between the two options. This is a micro-optimization.
But to answer the question - the straight markup would perform better, as there is no need to deserialize the control and operate on it server side.
In general, if you use a server side control, the server will need to do more work than with plain markup.
It has different goals.
The Label is used with the for key which represents an alias of refer to another control
the asp:label is merely span generated.
as a speed matter : label wins.
I would say you'd only need to use asp:label if you're planning to populat it dynamically (i.e. from code-behind) or if you want to use the "for" attribute with another server control (such as asp:TextBox). Otherwise, use the straight-html solution - your markup will be cleaner and it will be easier to identify the dynamic elements in the page.
From a performance point of view: use the HTML <label>.
Besides that, a label is usually used together with another (input-) element, e.g. <label for=...>. The same is true for the ASP.NET label: <asp:Label AssociatedControlId="..." .../>.
If you want to render plain text, a simple <span> (or no HTML element at all) might be better suited. And the ASP.NET equivalent for that would be <asp:Literal> (e.g. if you need to access it from the code-behind).
Related
How do I pull a value from an "asp:TextBox" and pass it in an anchor tag?
txtTaskName is my "asp:TextBox"
Add Email Distribution Lists
I know this should be simple and I've done it before, but am in a crunch and don't have my old sourcecode. Thanks All.
If you have your control already filled, you can use
<a href='EmailManager.aspx?<%=txtTaskName.Text %>'>Add Email Distribution Lists</a>
If you want to do it on change, you should use PostBack="True" and an OnTextChanged event (server side) for txtTaskName control, or use Javascript (client side).
Perhaps you could use a <%= ... => displaying expression rather than a data-binding expression?
Add Email Distribution Lists
I do not think you would have to specify runat="server" either in this particular example.
You can get more information on inline expressions from this article.
Note that this will only work if txtTaskName.Text has a value before the inline expression is evaluated, else the value will be string.Empty.
I want to add a bunch of classes to some text fields so i can get their values with jquery. This seems like standard practice when using jQuery and this post suggests it as the answer but how does this affect page loading? Won't it be trying to find all these classes? I have been told in the past to try minimise the amount of classes used on controls.
I have about 12 controls i'll want to add unique classes to to get their value. I am using asp.net so I can't use the id. I also can't use the ClientID as the controls are in a table (but only 1 set of controls will show at any one time).
e.g.
<asp:TextBox ID="txtValue1" runat="server" CssClass="value1" Text='value1' />
<asp:TextBox ID="txtValue2" runat="server" CssClass="value2" Text='value2' />
<asp:TextBox ID="txtValue3" runat="server" CssClass="value3" Text='value3' />
...
var value1 = $('.value1').val();
var value2 = $('.value2').val();
var value3 = $('.value3').val();
And none of the class names will exist in css.
Thanks
Edit:
I know this works but I was more curious about the affect it had on page loading. There was an answer (seems to be deleted now) that said something like the html parser ignores the classes. The css parser will only look at classes that are defined. So it sounds like it would be completely ignored and have no affect on page load. Is this right?
It is okay to use a CSS class that doesn't exist, but if they are unique you want to use id, not class.
You say you are using ASP.Net so you can't use the ID parameter, but you can. In JQuery you can get the controls using the below
var value1 = $('[ID$=yourID]').val();
For more info on JQuery Selectors check out: JQuery Selectors and Attribute Ends With Selector
The above selector basically finds the id ENDING in "yourID" so ignoring all the masterpages extra text at the start. You just have to make sure these are unique. e.g. don't have ids like "HSBC" and "SBC" as the above selector on "SBC" will find both.
I don't think it's a problem. The only times I've had problems with non-existant classes or ID's is one time I had an onclick reference an ID that didn't exist. This messed things up...Other than that I think classes are pretty harmless. I'd be interested to know though..
Any other thoughts??
Which version of asp.net are you using? In asp.net 4.0, you have the ability to use unmangled ids. It looks like the simplest solution would be to set ClientIDMode="Static" to all of your textboxes and then refer by id. Otherwise, sure, I've created classes that don't exist to refer to things.... all the time.
Edit: (in response to your comment about the effect page load).
I think your question about having extra classes in a div that are not currently used is not a bad question (at least in a theoretical sense), and I honestly don't know the precise answer. I do believe any effect is quite minuscule. If you consider best practices to write html, you generally write and structure the HTML, with it's classes, before you write the CSS. This means at the time you write the CSS, certainly some classes will not be used. Indeed, after styling the basic tags (body, h1, a, etc), you may find you never need to create selectors with those classes for some particular design. And yet for the next design, you might need those classes. I'm pretty sure the technology behind CSS was built with those kinds of scenarios in mind, and I bet millions if not billions of pages on the internet follow that exact scenario, especially if they use something like Modernizr, which adds classes to the html element of the page as a way of providing you classes you can select against considering the possible capabilities of the current browser. You may never need those classes, but they are there if you need them.
I've seen all of the usual pages with information about how to create a sub-tag that allows content within a user control (using ITemplate and INamingContainer) but I've yet to see anyone able to add properties that become attributes to said tags, for example:
<asp:MyControl runat="server" ID="myControlTest" SomeAttribute="SomeValue">
<Content ContentAttribute="Something">
Blah
</Content>
</asp:MyControl>
If you see the ContentAttribute on the Content tag, that is what I'd like to be able to achieve, but if I set it all up using ITemplate and INamingContainer etc, I can add a property that does in fact appear in Intellisense for that tag but when I run the code, it says Content does not have property/attribute named ContentAttribute (it also gives the same as a warning in VS IDE but still allows me to compile it).
I have tried everything to make this work and so far the only way seems to be if I make the Content property on MyControl a class that inherits from System.Web.UI.Control and implements ITemplate. That works but unfortunately I have to specify the runat attribute on the Content tag (because it sees it as a control rather than a sub-tag) and I'd rather not do that if possible.
Hope I have explained this well enough, if I haven't please let me know and I'll do my best to elaborate further.
Thanks in advance.
I think what you're proposing is something like a MIME email where there are a variable number of sections, each with an identifier for the client to choose the best version of the email it can handle. I assume you're wanting to select the appropriate template at runtime, based on that attribute.
The standard .NET controls don't implement that way, so far as I can tell. Think of the Repeater which has:
<asp:Repeater id="myRepeater" runat="server">
<HeaderTemplate>...</HeaderTemplate>
<ItemTemplate>...</ItemTemplate>
<FooterTemplate>...</FooterTemplate>
</asp:Repeater>
Each of the subitems (templates) has a different name, not the same name with a separate attribute.
Is there any way for you to define, ahead of time, what all of the possible sections might be, the way the repeater does?
<asp:MyControl runat="server" ID="myCtlTest">
<SomethingTemplate>Blah</SomethingTemplate>
<OtherTemplate>Blah</OtherTemplate>
</asp:MyControl>
I'm guessing not but wanted to throw it out there in case.
Alternately, could the ContentAttribute move to MyControl? The SETter would then load/build the template for you depending on the value.
<asp:MyControl runat="server" ID="myCtlTest" ContentAttribute="Something">
<Template></Template>
</asp:MyControl>
...or it could be loaded with a method instead of using the property SETter.
If you will always need multiple templates, perhaps a combination of those two concepts would help.
<asp:MyControl runat="server" ID="myControlTest"
SomethingTemplate="Something"
OtherTemplate="Other">
<SomethingTemplate></SomethingTemplate>
<OtherTemplate></OtherTemplate>
</asp:MyControl>
Coming from the world of HTML, XML and PHP its a new way of thinking when making web applications using ASP.NET. I'd like to use the following code in my MasterPage:
<div id="leftnav">
<asp:ContentPlaceHolder ID="leftnav" runat="server">
</asp:ContentPlaceHolder>
</div>
But since leftnav in this example is used twice, Visual Studio make a small but noticable protest. How should I think in this situation, and which is the most appropriate use of naming ID's in ASP.NET.
I don't like the default naming since id="ContentPlaceHolder1" says nothing of the content.
Thank you for listening!
I would call the div "nav" and the placeholder "navPlaceholder". This is because the word "left" implies position, which should be handled soley by your css, not your html. What if the designers decided they wanted to put the navigation on the right? You could do this in your css, but you would end up with something confusing like div #lefnav { float:right; } a trivial example, I know but something to keep in mind.
How about "leftNavPlaceHolder"?
Just as along as your consistent with your naming convention :)
No, the default IDs are terrible. I can't imagine they're meant to be used, it's just that Visual Studio isn't intelligent enough to suggest anything better, and they're not suggesting something semi-intelligent, because they don't want to try to come off as something they're not. Reasonable =)
So make a habit of always changing the default IDs. What you change them to is completely up to you; "leftNavContent"? Pretty much the only thing that's coverned by convention is capitalization, when it comes to IDs.
The only thing that should really change from pure HTML is that you can't use IDs like "left-navigation", i.e. containing hyphens, for server controls.
I would suggest, don't give id to div unless you really need, because it will impact on performance.
Subjective. The obvious answer to this type of question is: Pick something that you like; standardise it, and always follow it.
Personally, I name my things in the following fashion:
<asp:Literal runat="server" ID="ltlDescriptionOfContent" />
or
<asp:PlaceHolder runat="server" ID="plhSendMessage">
</asp:PlaceHolder>
For an area that contains, yes, information about sending a message. But you don't have to do this. Do whatever you want. Just make it consistent. And ideally, convey a little information about what is within.
I prefix all ASP.Net controls with ux to mean user control.
Then you can hook up your String emailAddress = "test#abc.com"; to your uxEmailAddress.Text = emailAddress
I am trying to find the best practice for generating and outputting html which would require a database query first to obtain the info. Currently in the aspx page I have a div with runat server:
<div runat="server" id="leaflet"></div>
Now just as a start to do a bit of testing I have a method that runs on page_load that basically does:
private void BuildLeaflet(string qnid)
{
//gets leaflet details
QueryLeafletDetails();
//return concatenated content string
leaflet.InnerHtml "<h1>" + dr["LSC Descriptor"] + "</h1>";
}
In the real solution the return is a concatenation of about 10 fields some very long as they are content.
I don't by any means think this is the best solution, but what is? A StringBuilder? Can I Write Each Part in turn to the site avoiding the concatenation in the method? Is the server div even best?
Edit: Forgot to put some of my content sections have simple (limited) html in them already such as paragraph, list... This allows me to easily produce documents for web and printing, I just use different stylesheets.
I would use <asp:Literal runat="server" enableViewState="false" id="leaflet" />. This doesn't generate any tags on the page, and doesn't stuff all the text in the ViewState.
And yes, use StringBuilder if you need to concatenate many long strings. This will be way more memory efficient.
The other solution would be to see if you can make some fixed markup on the page and put the contents of each DB field in it's own control (<asp:Literal />?).
I'd use either string.Format, if the number of fields is fixed (and relatively small), or a StringBuilder, otherwise. Readability of the code would be my guide, less so performance. You might also want to think about abstracting this out into a UserControl if you plan to reuse it. Then you could give it settable properties and build the render logic into the control to avoid repeating yourself.
Various people have benchmarked this - iirc format is fine for <4 items, simple concats for <7, stringbuilding above that.
I strongly advise against creating HTML as strings btw.