Thursday, October 25, 2007
GridView must be placed inside a form tag with runat=server
A few simple lines of code would typically handle this:
string listRecipients = ConfigurationManager.AppSettings["candidateTestEmailList"].ToString();
StringBuilder sb = new StringBuilder(2000);
pnlResults.RenderControl(new HtmlTextWriter(new System.IO.StringWriter(sb)));
//---------------------------------------------------------------------
// Send to the mail handler class
//---------------------------------------------------------------------
MailHandler mh = new MailHandler();
mh.SendMail(listRecipients, "Test Results " + tbName.Text, sb.ToString());
But I was getting the error...Gridview must be placed inside a form tag with runat=server. And of course it is, and the panel and the label are not throwing a similar error. I found this nifty fix:
public override void VerifyRenderingInServerForm(Control control)
{
return;
}
found it here: http://blogs.x2line.com/al/archive/2004/10/08/576.aspx
and it worked like a charm. I didn't spend more time investigating which controls require the fix, but if I see the error, I know where to start. Thanks Anatoly!
Wednesday, October 17, 2007
Blow by Blow Heavyweight Fight -Marriage of Yahoo API Widget with ASP.Net 2.0
When I say really simple, that was the theory, the reality was a little different. The problem was, embarrassed to admit this, our job postings and our press releases are static text on our website and when HR comes up with a new posting, it takes a developer time to release a new page. So, I want to free up our developers from spending time on administrative tasks such as these. Duck soup, right? Well, I also wanted to get my feet wet with some of the new widgets in the Yahoo Javascript API library...two birds with one stone!
I already have a project open in my VS2005 IDE, so I created a new page and copied and pasted my Yahoo code in. That took all of 5 minutes. The control that sees all the action is a textarea. I took the default markup from Yahoo and added runat=server attribute; this is all you need to expose your HTML controls server-side. Here are the steps I'm going to take in my code-behind to hook up this control to my html txt job postings files:
- Pass in my job id in my query string; this id will be the name of the txt file without the extension.
- Use the System.IO namespace.
- Use the StreamReader to get the contents of the text file and place it in the text area.
- Use the StreamWriter to get the contents of the text area and write it to the file.
- I have the ability to overwrite the original file or create a new file, but that is just a detail.
This was the code for the Page Load event:
if (!IsPostBack)
{
//read query string and include a job if one exists
try
{
if (Request.QueryString["id"] != null)
{
job = Request.QueryString["id"].ToString();
//get the contents of text file
msgpost.Value = GetJobFileContents(job);
}
else
{
btnUpdateJobPosting.Visible = false;
}
}
catch (Exception ex)
{
msgpost.Value = ex.Message;
}
}
I also needed two supporting methods to do the Getting and Setting of the text file value:
protected string GetJobFileContents(string job)
{
string path = Server.MapPath("../jobs/");
path += job + ".txt";
StreamReader sr = new StreamReader(path);
string strContents = sr.ReadToEnd();
sr.Close();
return strContents;
}
protected void SetJobFileContents(string job)
{
string path = Server.MapPath("../jobs/");
path += job + ".txt";
StreamWriter sw = new StreamWriter(path, false);
sw.Write(msgpost.Value);
sw.Close();
}
Adding all this to the code behind took about 15 min. Then I hooked up my click events, I had two buttons, one for Updating and one for saving a new file with a textbox to put in a filename.
At this point you may be asking why I'm using server-side code with a javascript API. Well, to write a file to the server, you have to use server-side code. I can execute a server-side function with JSON using AJAX on the client, but that's more work than just using the native .Net postback events. The only reason NOT to use the postback events is to minimize round trips to the server (we've already said we have to go to the server!) or to give the user a better experience without an entire page refresh...very valid in most cases, but not in mine; this control takes up the whole page, it's the raison d'etre (raze-on det: reason for being ) of the page.
So yeah, I took the easy road and didn't really go through my paces with the new API, so the payback was, YES, it didn't work! All the events were handled properly, executed perfectly, as planned, files were read, files were saved, but no changes were reflected. Putting a breakpoint on the sw.Write(msgpost.Value) line revealed that the value of the textarea was the old, unedited value. I tried changing the property I was reading, using InnerText and InnerHtml instead of Value, but they all gave me the same data. I also tried reading the Request object with no luck, it also held the old, before-edit value.
I remembered back in the days of 1.1 where the autoeventwireup used to execute all the code twice so I stepped through the code from start to finish to determine that I was NOT reading from my file and overwriting the changes with the old text. My whopping 20 lines of c# code were doing exactly what i wanted. So I commented out my API code on the client (aspx), and made it a plain textbox, and VOILA, I was getting exactly what i wanted, but my rich text editor was gone. Now I actually had to read the documentation to see what my options were.
I found this little property:
handleSubmit -
Boolean
Config handles if the editor will attach itself to the textareas
parent form's submit handler. If it is set to true, the editor will attempt to
attach a submit listener to the textareas parent form. Then it will trigger the
editors save handler and place the new content back into the text area before
the form is submitted.
Default Value: false
So I changed the value to true, and we got some good news and we got some bad news. Good news is that the value of the textarea now reflects the changes made, but the bad news is my buttons now fire the Page_Load event, but not the click events. So now I'm two hours into what I planned to be a half-hour quickie, so I just threw in a hack. I hooked up the following to the else block of my !IsPostBack check:
else
{
//we're saving the contents
try
{
if (tbJobPosting.Text.Length > 0) //we're writing to a new file
{
//remove .txt if it's in the filename
job = tbJobPosting.Text.Replace(".txt","");
//set the contents of text file
SetJobFileContents(job);
//redirect to page
Response.Redirect("../jobs/jobposting.aspx?id=" + job);
}
else //we better have a query string
{
if (Request.QueryString["id"] != null)
{
job = Request.QueryString["id"].ToString();
SetJobFileContents(job);
}
}
}
catch (Exception ex)
{
lblUserMessage.Text = ex.Message;
}
}
It isn't pretty, but it works. It's not even the best, free, rich-text editor out there, and I'm sure I'll be replacing it with something else, but I learned some interesting things! Oh, and if you're going to be allowing html content in your postback, don't forget to add validateRequest="false" to your Page directive, and make sure you're taking care of the security risk of doing so.
Tuesday, October 9, 2007
Quote for the Week
One of the quotes from the book was immediately compelling to me, so much so that I cut it out and pasted it on my computer.
"The person who can most accurately describe reality without laying blame will emerge the leader."There was more description around this point, but the power of the statement hits home without it. In my consulting world, we have a sunset review once a project phase has been completed. There is value to be gained from an analysis of what we did right, but the time and passion is always spent dissecting what went wrong, and the close cousin, who is to blame. The ability to recognize our mistakes and to learn from them is critical in any effort to improve a process, but our need to place the blame undermines trust and infuses a group of people who once acted as a team with a sense of isolation and a motive for CYA.
One of the reasons this was poignant to me is that I'm coming off a rather painful project completion, and I was challenged by the statement and realized that I wasn't exhibiting this critical characteristic of leadership, and yet by my project role and my own self-assessment I am a leader. My takeaway: Everything can be improved, even me!
Wednesday, August 1, 2007
Clearing Items in Repeater (or other) Control in .Net 2.0
I have a search control that dumps the results in a repeater, and to clear the results between search, I use the following line in my search click event:
myRepeater.DataSource = null;
whoop there it is :)
Thursday, July 12, 2007
Date Validation in .Net 2.0
- AJAX MaskedEditExtender
- Range Validator
What does the MaskedEditExtender give you? Only numbers are allowed and the
_ _ / _ _ / _ _ _ _ appear magically when the text field obtains focus. Here's what it looks like in your aspx source view:
<cc1:MaskedEditExtender ID="MaskedEditExtender3" runat="server" TargetControlID="txtBrideBDay"
Mask="99/99/9999"
MessageValidatorTip="true"
OnFocusCssClass="MaskedEditFocus"
OnInvalidCssClass="MaskedEditError"
MaskType="Date"
InputDirection="LeftToRight"
AcceptNegative="Left"
DisplayMoney="None"
>
</cc1:MaskedEditExtender>
The key fields to look at here are the mask and the mask type. The date mask only allows for numbers and the /. If you haven't added the AJAX toolkit to your webprojects, go here http://www.asp.net.
Now for the second piece. When you want a date to fall in a certain range, for example, scheduling an appointment, obviously the date needs to be in the future. Add a RangeValidator to your text field, select a validation type of Date, and put in your minimum and maximum values. For my application, this is what my RangeValidator looks like:
<asp:RangeValidator ID="RangeValidator1" runat="server" ControlToValidate="txtWeddingDate" Display="None"
ErrorMessage="Wedding Date cannot be in the past." Type="Date" MaximumValue="1/1/2050" ValidationGroup="GroupContactInfo"></asp:RangeValidator>
You can see that I don't care very much about the maximum date, setting it waaaaay in the future, and I haven't set a MinimumValue at all. This will throw a runtime error as both values are required for a RangeValidator. I've done this because future is not a definite date, it's dynamic based on the date the user is filling in the form. So I have to add it dynamically, which I've chosen to do in code-behind the first time the page loads:
if (!IsPostBack)
{
RangeValidator1.MinimumValue = DateTime.Now.ToShortDateString();
}
You can also put the value in the aspx page (which won't require compiling to change) with MinimumValue="<% =DateTime.Now.ToShortDateString() %>".
As always with the special validators, a RequiredField validator is needed for the RangeValidator to kick in.
Onward validation soldiers!
Tuesday, June 26, 2007
Aspdotnetstorefront Menu
What we lose here is the dynamic control of the menus for our clients, meaning they have to touch an xml file in addition to setting up the categories, and i don't know many product managers who speak xml.
So what I found was a curious line of code in the templatebase.cs file in app_code. Look at the Page_Load function and the section commented "// Find Categories menu top" and the line which starts with a call to AddEntityMenuXsl. See the final parameter being passed into that method is string.Empty. Well, when i look at AddEntityMenuXsl, I see that we have a piece of code that allows us to add a ROOT level element if the parameter length is greater than 0. So I just made my method call look like this:
AddEntityMenuXsl(doc, "Category", AppLogic.CategoryEntityHelper.m_TblMgr, mNode, 0, "1");
and VOILA! I now have a dynamic menu with the categories across the top! With just a little itty bitty code change. Some days programming is berry berry good to me :)
Thursday, June 21, 2007
Specified string is not in the form required for an e-mail address
So, if you have a large established code base, and you want to upgrade your mail class, just one class that you use for ALL your applications, what do you do to minimize your rework? My advice is to use the string replace function and just replace every instance of semicolon with a comma. That will handle the old code passing in semicolons as well as the new code passing in commas. Then you have one place to make the update and you can leave your legacy code alone.
If you are NOT using a single mail handler class across your applications, then you're working too hard!
Wednesday, June 13, 2007
Best Joke I've heard this week
It's such an inside joke, think back to high school chemistry. This is a t-shirt available at www.thinkgeek.com, which is my favorite website for truly geeky things, such as the t-shirt I got my husband, "I'm with Genius" and an arrow pointing up. If you need a break in your day, and little gadgets to proclaim your geekhood, check this site out.
Monday, June 11, 2007
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Don't bother with what the error message says, it's just a hiccup when the app starts thinking about an exit strategy for the war in Iraq.
Friday, June 8, 2007
ADA Compliance
The language of the Act is pretty vague and general, and those with bigger budgets are expected to make correspondingly more accomodations, and to muddle the muddy waters further, there's just no list to go by to say what is compliant and what is not.
There ARE however a couple of things that are just good practice anyway, the first of which using alt text for ALL images (except maybe corners on tabs and things like that). Sight-impaired visitors have devices that read the alt-text out loud so they can know what's on the screen in front of them. It's also a best practice for Search Engine Optimization, so just do it!
Another requirement from a recent client was to make the site keyboard navigable. This was a doozy. We had a pre-packaged component that came with aspdotnetstorefront, but it was a no-go for keyboard navigation. Our senior developer on the project, Tomas Vera found this nifty menu at http://www.milonic.com that you can tab into and use your arrow keys to navigate. This is a great find, IMO. Another tip for you, set your tabindex to 1 on your website logo so that if a user wants to tab through the page, they will always start at the top left. The only exception to this would be a search page where the user expects the focus to be in the search box so they can just begin typing.
Just one more disjointed rant from the trenches!
Thursday, May 17, 2007
Aspdotnetstorefront Menu
Here it is interesting to note that this menu is built on the fly, and you as a developer do not get to play with how this menu is created at runtime. I did some research on the NOBR tag and learned it was not css-friendly, but I took a leap of faith and added this to my stylesheet:
.TopMenuItem, .TopMenuItem NOBR, .TopMenuItemHover NOBR
{
background: #443A23;
color: #fff;
}
And voila! My css-styles were now applied.
I'm still struggling with the fact that the marriage between ASPDNSF and Component Arts is not flexible. If you decide to take your top categories horizontally across the top of the screen, you end up having to hard code your menu values in the menuData.xml file and you lose your tie to the category admin component. What this means is that if you change the name of the category, or add a new category, or make a category unpublished, these changes will not be reflected on the front end until you manually modify the xml data file. What a pain. If anyone has gotten around this little feature, I would give you a homemade chocolate chip cookie.
Tuesday, May 15, 2007
IE Developer Toolbar
And because I've used it in my post, I might as well tell you about TinyUrl. My developer-in-arms Pablo showed me this site and I use it all the time. If you have a horribly long URL, especially the encrypted versions, and you want to send a link to your peeps (or to your mother), then use this page: http://www.tinyurl.com. We've found that even Microsoft is using this tool in their MSDN pages :)
Monday, April 30, 2007
.Net web config error
The lines will look like this:
comment them out or remove them entirely and you're good to go.
The best bet when you get a strange webconfig error is to copy the entire text of the error and google it. That's the fastest way I've found to resolve runtime issues.
Thursday, April 26, 2007
Quick SQL
Tuesday, April 24, 2007
Publish in VisStudio 2005
So, a little trick I've come up with is to publish locally and then do a copy of only the bin directory and all ascx and aspx pages. For example, if I have a website under wwwroot (I know it's not necessary with VS2005, but i'm old-fashioned) called MySite, I will have a sister directory called MySite_Build. I publish to this directory and then copy to my remote servers.
When you publish, you have the option of local IIS and the file system. I would prefer local IIS because the path is simpler, but I find I get this error often:
"You must choose a publish location that is not a sub-folder of the source website." This error is confusing because the build directory is NOT a subdirectory and is in no way related to the source website. I haven't figured this out, when I get this error, I simply use the file system to identify the same directory and it works like magic. Go figure.
We'll be moving to the 3.0 framework pretty soon, but we'll still be working in vs2005 for awhile to come, so if anyone has any publishing tips, I can certainly use them!
Thursday, April 19, 2007
ADP Taxware Web API integration
ADP Taxware is a program that runs on a server. We have it running on our webserver with our website; currently our load allows this configuration. When the website calls the Taxware API, it needs access to the \program files\taxware directory. You MUST allow the internet anonymous account access to this directory or you will get an obscure error message, and stepping through the code will reveal it to be a permission denied error.
The only other quick advice I have to offer is make sure you copy your dlls to the system32 folder on your server; just residing in the taxware folder (where the install puts them) doesn't seem to be sufficient.
Finally, although Taxware's documentation is cumbersome, their tech support guy on this API is fantastic, his name is Jonathan Wang. Happy coding!
Wednesday, April 18, 2007
Aspdotnetstorefront Out-of-the-box Build Error
Before I did anything else, I tried to build the solution. I was unsuccessful, and of course, seriously perturbed...I may have said unfriendly things...so I sent an email off to tech support with a copy of the error.
I received a quick response (you gotta love responsive tech support) and they noted that I seemed to be referencing a file that should not be in that build.
I deleted all my files, extracted the download to my newly clean directory, and before I did anything with Visual Studio, I opened the sln file in text editor and modified all the paths in the solution to point to my correct directory. You will have this problem if you try to run more than one storefront solution side-by-side. I saved the sln file. Opened my project, all problems solved. To be safe, I renamed my sln and suo files to match my directory name.
I'm fairly new to this storefront thing, so if you have any tips to share, i'm all ears.
Friday, April 13, 2007
Faster Filter Queries
We should all now be indoctrinated enough to know the holy trinity of fast queries in .Net:
- Stored procedures – NOT inline SQL
- Table indexes – see your DBA if you’re unsure
- Data Readers (if your data is read only)
I am also a strong proponent of the Microsoft Application Blocks, especially the Data Application Block. You will save yourself a lot of time, your code will be cleaner and easier to read, and your data activity will be optimized. (download here).
So that’s all good, but what I really want to talk about is an optimization that Nuri showed me for the query itself.
I was writing a standard read-only report on movie data in a GridView, and I had several filters for the users, such as date range, metro area, film, etc. My query passed in 0 (zero) for all filters that were unused. My initial WHERE clause looked like this:
WHERE (o.PostedDate BETWEEN @begindate AND DATEADD(d,1,@enddate) )
AND (o.FilmID = CASE @filmID WHEN 0 THEN o.filmID ELSE @filmID END)
AND (o.ContactID= CASE @contactID WHEN 0 THEN o.ContactID ELSE contactID END)
AND (o.MarketID = CASE @marketID WHEN 0 THEN o.MarketID ELSE @marketID END)
AND (o.NewspaperID = CASE @newspaperID WHEN 0 THEN o.NewspaperID ELSE @newspaperID END)
Well, that does the trick, but it’s not efficient. In the case of 0, I am still putting a requirement on the parser to go through each row and verify that the value equals itself, and the optimal solution is that the parser simply ignores the filter if a 0 is passed.
The optimized WHERE clause looks like this:
WHERE (o.PostedDate BETWEEN @begindate AND DATEADD(d,1,@enddate) )
AND ( @filmID = 0 OR o.FilmID = @filmID )
AND ( @contactID = 0 OR o.ContactID = @contactID )
AND ( @marketID = 0 OR o.MarketID = @marketID )
AND ( @newspaperID = 0 OR o.NewspaperID = @newspaperID )
Much better, right? If you have any query optimization tricks to share with me, I’d love to hear them.
Who I really work for
Funnier Than I
.Net Heroes
- Muliadi's Blog - CSS Masterblaster & more
- Pimp Daddy's site - it's not all about the dotNet, can u say PowerShell?
- Patrick's Blog - .Net Commerce & Cold Fusion
- Nuri's Blog - If you don't know, Nuri knows :)
- Max's Blog - Microsoft Product Manager for Commerce Server 2007
- Pablo's Blog - First to try the latest technology
Article Categories
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About Me
- Robin
- I am a senior .net web application developer in Phoenix, Arizona specializing in eCommerce and intranet applications. My LinkedIn Profile