I want my C# code to get the currently-selected option from an HTML5 dropdown list. Our situation is perhaps a bit different from many others, since this is not a client-server web app, but rather a desktop app which uses HTML for its UI in order to be more portable to Linux. To support this, we use an embedded Firefox browser with the Gecko engine.
I'm new to working with HTML using C#, and I can't seem to find the right API call for this.
The HTML looks like this:
...
<div class="select">
<select id="ddlMyOptions" name="ddlMyOptions">
<option></option>
<option>first choice</option>
<option>second choice</option>
</select>
</div>
...
And the C# code I'm using to try to access it is:
IHTMLElement selectElement = documentHTML.GetElementByID("ddlMyOptions");
string value = selectElement.Items[selectElement.SelectedIndex].Value;
string text = selectElement.Items[selectElement.SelectedIndex].Text;
This is based on examples I have seen from other posts, but those posts are using asp.net and in my case Items and SelectedIndex are not defined for selectElement.
Also, I have seen some posts about using Javascript, but I would prefer to keep this all in C#, if possible.
I looked at what it would take to have a callback method on the dropdown, so I could get the selected value whenever it changed and save it to an instance variable in my class, but I wasn't able to figure out how to specify the callback method, either.
Any help would be highly appreciated!
Since there were no answers to my question, I went ahead with a JavaScript solution:
function updateDDLSelection(elid) {
var el = document.getElementById(""ddlMyOptions"");
var val = el.options[el.selectedIndex].value;
el.setAttribute('value', val);
}
Then, I had to change the HTML from what was shown above to this:
...
<div class="select">
<select id="ddlMyOptions" name="ddlMyOptions" onchange=""updateDDLSelection(event)"">
<option></option>
<option>first choice</option>
<option>second choice</option>
</select>
</div>
...
And here's the revised C# code to get the value that was set by the JavaScript function:
IHTMLElement selectElement = documentHTML.GetElementByID("ddlMyOptions");
string value = selectElement.GetAttribute("value", 0).ToString();
Hope this is helpful to someone else who is in a similar situation...
Related
I'm a .Net Core beginner and look for a solution to protect the application from IE.
I got the following code working in Controller:
string userAgent = Request.Headers["User-Agent"].ToString();
var flagsIE = new [] {"MSIE", "Trident"};
if(flagsIE.Any(userAgent.Contains)){
return RedirectToAction("BadBrowser");
}
Now if someone is trying to visit the page using IE, they get redirected to an info-page asking them to use a modern browser. Instead of adding this code to every single Controller.cs I would like to add it on project level, so that it get's executed independent from the location within of the project.
And, I know that this can be achieved with _Layout.cshtml, my question is:
Where and how would I implement a function to get it executed for all requested views withing the project without adding it every single request within Controller.
Thank you in advance.
As Icepickle suggested, in the comments of my question, I used middleware in Startup.cs and got the desired result:
app.Use(async (context,next) =>
{
string userAgent = context.Request.Headers["User-Agent"].ToString();
var IEkeywords = new [] {"MSIE", "Trident"};
if (IEkeywords.Any(userAgent.Contains)){
context.Response.Redirect("/IE/redirect/badbrowser.html");
return;
}
await next();
});
You can try to add js in _Layout.cshtml to detect the browser is IE:
<script>
var isIE = false || !!document.documentMode;
if (isIE) {
window.location.href = "/Home/ForbidInfo";
}
</script>
Then create a view named ForbidInfo under Home controller which to show the message to user that he cannot use the IE to show views.
(Notes: this view's Layout must be null ,or it will enter an endless loop)
#{
ViewData["Title"] = "ForbidInfo";
Layout = null;
}
<h1>Please use a modern browser!</h1>
After these settings, when you running a view in IE, it will be redirected to the FordidInfo page.
If your page does not use _layout, then you need to add the js on the corresponding view separately to ensure that it will not be displayed in IE.
Never do that. Excluding browsers with redirects, is what lead to massive user agent spoofing. Effectively making that AgentId useless. And the way you wrote it, you may get a lot of false-positives.
It is also a bad idea from the early days of the internet, we are hoping to get rid off:
https://en.wikipedia.org/wiki/User_agent#User_agent_spoofing
How to change the value of data-href in dotnet code behind Approach. Please i want to write different value in datahref attribute using query string
<div class="fb-comments" id="abc" data-href="https://www.facebook.com/Khaanaabaadosh" data-numposts="5" data-colorscheme="light" runat="server"></div>
Is this what you are looking for?
In your C# code, you should be able to do
abc.Attributes["data-href"] = "your custom link";
I am working on a web application that will be going live soon, and I am now trying to figure out the best way for handling sending email from the application. I understand completely HOW to send email from the application using the MailMessage and SmtpClient classes, however my question is from a different angle. My main purpose at my job before this project was support of old applications that had been developed before my time. In these applications, when they needed to send email, they hard coded any of the messages into the actual message with all of the HTML tags embeded directly into the C# code.
The application that I am working on will have a template for the emails to be sent in, as a sort of styling container, and the different messages will be embeded into the main content div's of the template. I would like to avoid hardcoding these templates in this application, so I have been trying to figure out the best way to layout my project. I have thought of using a t4 template, and reading the different t4's into the application and applying a String.Format with the specified parameters to add names/emails to the messages to be sent. However, I am not sure this is the best way to do it.
My other idea was to define a class for each type of message, however this would end up hardcoding messages again, which as I said I don't want to do.
My question is, how have you approached this in the past? What worked, and what didn't and for what reasons? I have looked all over online, but either the only content out there is on HOW to send the message, or I have not used the right Google power words.
I do it this way:
Code it the usual way with ViewModel and Razor Template
By creating the e-mail, use http://razorengine.codeplex.com/ to load and parse the template
Be aware to not use Html and Url helper if you want to send e-mails in a thread, because they rely on HttpContext which you don't have in that case. Build your own helpers if needed.
For example, if you have a ViewModel Car in your application which is displayed somewhere, you could also use this ViewModel as #model in a Razor Template for e-mail.
I've had to do this on a couple of occasions. I originally used the ASP.Net template engine based on I think a Rick Strahl blog post. It worked but there was always some issue I was banging my head against.
I switched to using the NVelocity template engine and found it a really simple way to create and maintain email templates. There are a number of other template engines and I suspect next time I might have a serious look at the Razor engine.
The code for merging values into the template:
private string Merge(ManualTypeEnum manualType, Object mergeValues)
{
var body = "";
var templateFile = string.Format("{0}MailTemplate.vm", manualType);
var velocity = new VelocityEngine();
var props = new ExtendedProperties();
props.AddProperty("file.resource.loader.path", Config.EmailTemplatePath);
velocity.Init(props);
var template = velocity.GetTemplate(templateFile);
var context = new VelocityContext();
context.Put("Change", mergeValues);
using (var writer = new StringWriter())
{
template.Merge(context, writer);
body = writer.ToString();
}
return body;
}
The values to merge are passed as an anonymous object, and can include various types including lists etc e.g.
var emailBody = Merge(newDocument.ManualType, new
{
ManualType = newDocument.ManualType.ToString(),
Message = change.Message,
NewTitle = newDocument.Title ?? "",
NewVersion = newDocument.Version ?? "",
Contact = From,
Changes = change.ToList(),
});
I've got some (badly written) legacy code that I have to modify but I'm having an odd problem with the prefixing of the controls.
The main page has several include files, including cpct_cost.aspx.
Within that included page is a control EquipmentCost:
<INPUT id="EquipmentCost" type="text" name="EquipmentCost" runat="server" size="10" onchange="TotalCost();" class="bk">
Another page references that control in client side javascript:
function TotalCost()
{
var a = document.CPCT_FORM.cpct_cost_EquipmentCost.value;
This is throwing a client error because when I run the code locally, the control is being named with a $ instead of an _:
<input name="cpct_cost$EquipmentCost" type="text" id="cpct_cost_EquipmentCost" size="10" onchange="TotalCost();" class="bk" />
And as a result, the client side javascript can't find the element in question.
The legacy code on the server handles this differently - the control name there is processed as:
<input name="cpct_cost:EquipmentCost" id="cpct_cost_EquipmentCost" type="text" size="10" onchange="TotalCost();" class="bk" />
and this is being processed correctly.
I thought at first it might be a local IIS setting, so I compiled my code and deployed it to the dev server, but the behavior was identical to my local execution.
I'm using what are supposed to be the latest source files, I haven't changed any project settings, so ... is there some way I can force the code from my machine to use the : instead of $? Or ... what am I missing?
The project is currently on the proposal list to be completely rearchitected, (so please, no suggestions to redesign the app ;) ) but in the mean time, I have a short term requirement to implement some minor new functionality in this ugly old beast, and I've got to get it done ASAP. What's frustrating is - I haven't changed these parts of the code at all, but the behavior is changing anyway.
UPDATE
Apparently the naming prefix used in at least .NET 1.1 is somewhat random, because after several builds, while I was trying various ways to work around this, the controls ended up getting the right name. So now I'm just not changing the code, which sucks because I really hate taking this "freeze it while it's randomly right" approach.
You could pass in a reference to the input control as a parameter to the JS function, ie:
<INPUT id="EquipmentCost" type="text" name="EquipmentCost" runat="server" size="10" onchange="TotalCost(this);" class="bk">
function TotalCost(txtEquipCost) {
var a = txtEquipCost.value;
}
Then it doesn't matter what the id is.
EDIT:
If you have more controls, create JS variables on the page, eg:
var txtEquipCost = document.getElementById('<%= YourControl.ClientID %>');
var txtOtherCost = document.getElementById('<%= YourOtherControl.ClientID %>');
Then the onChange function call could be TotalCost(txtEquipCost, txtOtherCost)
EDIT2:
See this question about ClientId and UniqueId which may be useful:
C# asp.net Why is there a difference between ClientID and UniqueID?
You could change your Javascript to use the id that is getting generated.
function TotalCost()
{
var a = document.getElementById('<%= YourControl.ClientID %>').value;
}
Also if you need absolute control over the generated id of that control it turns out that in asp.net 4.0 the ClientIDMode property was introduced so that developers have more control over how that id is generated.
Check out these two sources
http://msdn.microsoft.com/en-us/library/system.web.ui.control.clientid.aspx
http://weblogs.asp.net/asptest/archive/2009/01/06/asp-net-4-0-clientid-overview.aspx
I am trying to call a JavaScript function on click in a MVC2 View Page.
<a onclick=" SelectBenefit(<%=o.ba_Object_id %>,<%=o.ba_Object_Code %>)" href="#">Select</a>
JavaScript function
function SelectBenefit(id,code) {
alert(id);
alert(code);
}
Here ba_Object_Id and Code are the values from the ViewModel. If I use SelectBenefit(<%=o.ba_Object_id %>) in this way, its working fine. But when I have two paramaters its not.I am getting this error:
conditional compilation is turned off.
I think that you need to put quotes around the second parameter if it is a string:
<a onclick=" SelectBenefit(<%=o.ba_Object_id %>, '<%=o.ba_Object_Code %>')" href="#">Select</a>
This being said your parameters need to be properly encoded and I wouldn't pass them likse this. I would serialize them as JSON object to ensure that everything is OK. Like this:
<a onclick="SelectBenefit(<%= new JavaScriptSerializer().Serialize(new { id = o.ba_Object_id, code = o.ba_Object_Code }) %>)" href="#">Select</a>
and then the SelectBenefit function might look like this:
function SelectBenefit(benefit) {
alert(benefit.id);
alert(benefit.code);
}
I'm guessing o.ba_Object_Code is not a number? Try putting quotes around it:
<a onclick="SelectBenefit(<%=o.ba_Object_id %>,'<%=o.ba_Object_Code %>')" href="#">Select</a>
You could also write this function like this:
Select
Or use Jquery (best approach, imo):
$('#yourlinkid').click(function(){
SelectBenefit(<%=o.ba_Object_id %>,'<%=o.ba_Object_Code %>');
return false;
});