I have a situation where I make a with some Razor. This is pretty standard, so imagine something like:
<div>
<strong>Undertegnede myndige skyldner</strong>:<br /><br />
#Model.ContractText.DebtorName, #Model.ContractText.DebtorFullAddress
#foreach (var reminder in Model.DemandStructure.ReminderFees_Lines)
{
#reminder.Label #: #reminder.Amount.ToCurrency()<br />
}
</div>
This becomes a nice piece of text.
What I want to do, is to POST this generated text, and store it on the server.
Possible solutions
Now, I could of course just generate this string on the server, but then I would loose the nice formatting of Razor.
I could use some templating language - but I am not familiar with anything that is easy and solves my problem to use on the server side?
Maybe it makes sense to wrap this in some kind of input field so it's POST-ed to server?
Does anyone have a simple and smart solution for how to POST a generated text-string to the server?
Do you mean post the text to the server in relation to a user action on the page?
If not, certainly do it server-side instead, and even in that case while yes, you potentially could wrap it in a form element (or probably wrap a copy of the text in for example a hidden element) and that will be submitted with any form submits - you probably shouldn't do this for a number of reasons;
The user will be able to edit the text before it is send to the server, and it looks like they shouldn't be able to, as then they could change the Amount value before it is stored
It will be hard to encode the newlines (they are br elements in your HTML but these don't post correctly to a newline in a string so you would have to convert them, or use a textarea instead)
It generates unnecessary network traffic.
What you should probably do is simply store it on the server-side code, using a format string to create the same resultant text;
var theText = $"Undertegnede myndige skyldner:{Envionment.NewLine}{Envionment.NewLine}{Model.ContractText.DebtorName}, {Model.ContractText.DebtorFullAddress}
{String.Join(Environment.NewLine, Model.DemandStructure.ReminderFees_Lines})";
Related
I am developing a web application in which we have generated labels with barcode. Now we need to read these labels during packing stage.
I understand that Barcode scanners work as keyboard entry so I have created a View with text box to read the barcodes from labels. When I scan any label its reading barcode and automatically directing to some search page.
View
<td>
#Html.TextBoxFor(model => model.StyleNumber)
#* <input type = "text" style="border:0px;" value = "" />*#
</td>
There are 2 issues :
Automatically append row with a text box with for each label
Not to direct to some other page and have all the scanned labels on the same page to be read and used for further processing.
I have tried a lot but didn't find anything concrete. Please advise.
I'd like to suggest to move in this direction:
Obtain technical specification of barcode reader
Barcode should add some "begin and ending char" before and after the barcode read
Example if you barcode in 123456 reader can add 123456/n
where /n is new line or something else
You can monitor keydown of text field and monitor when text change and you detect ending character, at this point you can submit the form that contain your textbox. You can use javascript/Jquery
http://www.aaronkjackson.com/2011/02/quick-tip-use-jquery-to-submit-a-textbox/
This example if the first that I've found but it can be improved for example sumitting a form without button
You can perform barcode validation on server side
At this point you can process barcode on server side and return void from controller method. Y
You can improve solution providing some better user experince for example validating barcode client side or hide the text control or submit data using jquery insted of form like this:
How to send data in jquery.post to mvc controller which use ViewModel as parameter?
Pay attention on setting focus over control otherwise if user ckick mouse out of text control the text read form barcode reader isn't inserted into textbox.
I think that could be possibile develop some ActiveX but this is more invasive solution
HTML5 is your answer. But it will work in HTML5 compatible browser only. If you are targeting older version of browser you need to create Activex which is pretty old and not secure.
There is a jquery plugin for reading QR and Barcode which is worth looking into it.
http://dwa012.github.io/html5-qrcode/
Another way is doing capturing it on mobile devices with HTML5
http://www.html5rocks.com/en/tutorials/getusermedia/intro/
There is a paid option also.
http://www.visionsmarts.com/products/barcode-shell.html
I am currently writing a small templating system in ASP.NET to allow users to add content. For example, the user can enter the string (variable type is string).
topHeader[x] = "They think it's all over. It is now!";
However, one change that's needed is the ability to add some basic HTML tags within this content, so the following can be done
topHeader[x] = "They think it's all over. <strong>It is now!</strong>";
or
topHeader[x] = "They think it's all over. <a title="Football News" href="URL">It is now!</a>";
If you add such things into strings now they are not formatted as HTML, but I want to somehow escape them so that they can be. Naturally I've looked on the Internet for the answer, but as Razor is fairly new there's not much out there to help me out.
Anyone have an idea of how to do this?
You need to create an IHtmlString implementation holding your HTML source.
Razor plans to have a helper method to do this for you, but, AFAIK, it doesn't yet, so I believe you'll need to create your own class that implements the interface and returns your HTML from the GetHtmlString() method.
EDIT: You can use the HtmlString class.
You can either change your topHeader dictionary to hold IHtmlStrings instead of Strings, or you can leave your code as is, but wrap it in an HtmlString in the Razor view:
<tag>#new HtmlString(topHeader[x])</tag>
Make sure to correctly escape any non-HTML special characters.
The helper method they added is called Html.Raw() and it is much cleaner.
Here is an example:
#Html.Raw("Hello <a>World</a>!")
SLaks is right, but you don't need to write your own implementation of IHtmlString, there's one built in to System.Web called HtmlString. So:
topHeader[x] = new HtmlString("They think it's all over. <a title=\"Football News\" href=\"URL\">It is now!</a>");
Should do the trick.
In my markup I am using HTML title attributes which I set by the Tooltip property of various ASP.NET controls like an asp:Label. The content of those titles come from a database and I use data binding syntax, for instance:
<asp:Label ID="PersonLabel" runat="server"
Text='<%# HttpUtility.HtmlEncode(Eval("PersonShortName")) %>'
ToolTip='<%# HttpUtility.HtmlEncode(Eval("PersonFullName")) %>' />
Now, tooltips seem to be displayed as plain text on Windows and in the browsers I have tested. So the HTML-encoding is not what I really want and I am inclined to remove the encoding.
Can this be dangerous in any way if the database fields may contain script tags for example? My question is basically: Is it always guaranteed that HTML-title attributes are displayed as plain text? Are they always displayed as tooltips at all, or is it possible that some browsers (or OSs) display them in another way and allow and render HTML content in the title attributes?
Edit:
Looking at some of the answers it seems I didn't phrase my question well, so here are some additions:
If I have in the code snippet above a PersonShortName of "PM" in my database and as the PersonFullName a name with non-ASCII characters in it like Umlauts in "Peter Müller" the browser displays in the tooltip Peter Müller when I apply HttpUtility.HtmlEncode like in the code example - which is ugly.
I've also tested a simple HTML fragment like:
<span title="<script>alert('Evil script')</script>" >Hello</span>
The script in the title attribute didn't run in a browser with enabled Javascript (tested with Firefox), instead it was displayed in the tooltip as plain text. Therefore my guess was that title attributes are always rendered as plain text.
But as Felipe Alsacreations answered below there exist "rich tooltip plugins" which may render the title attribute as HTML. So in this case encoding is a good thing. But how can I know that?
Perhaps HttpUtility.HtmlEncode isn't the right solution and I have to filter only HTML tags but not encode simple special characters to make sure that the plain text is displayed correctly and to protect "rich HTML tooltips" at the same time. But it looks like a costly work - only for a simple tooltip.
Always sanitize output to the browser.
If a value like "><script>blabla</script> is inserted as a value for your fields, a user can essentially take over your entire site. It will probably make a mess when it comes to validation and correct code, but the script will still be run.
So to answer your question: No, it is not guaranteed that HTML-title attributes are displayed as plain text if the user knows what he/she is doing.
Beside security reasons:
Title attributes should always be plain text but certain JS plugins misuse them to display 'rich' tooltips (i.e. HTML code with bold text, emphasis, links and so on).
As for browsers and AFAIK they are displayed as plain text and tooltips, never displayed to those who use tabbed navigation (keyboard) and scren readers give to their users (blind and partially sighted people) many options, like reading the longest between link title and its text or always title or never ...
Surprisingly, still, no right answer in 5 years. The answer is: yes, you need to encode the title attribute, but not everything that is encoded in the innerText of the element.
The proper way to do it in asp.net if you do your own markup is:
string markup = string.Format("<div class='myClass' title='{0}'>{1}</div>",
System.Web.HttpUtility.HtmlAttributeEncode(myText),
System.Web.HttpUtility.HtmlEncode(myText));
The above will set both innerText and title of the div to myText, which is customary for elements that may contain long text but are constrained in width (as I believe the question implies).
The ToolTip property of a ASP.NET control will auto encode the value on output/rendering.
This means it is safe to set the tooltip to plain text as the page will sanitize the text on rendering.
Label1.ToolTip = "Some encoded text < Tag >"
Renders HTML output as:
<span title="Some encoded text < Tag >"></span>
If you need to use text that is already encoded, you can set the title attribute instead. The title attribute will not be automatically encoded on rendering:
Label1.Attributes("title") = "Some encoded text < Tag >"
Renders HTML output as:
<span title="Some encoded text < Tag >"></span>
Another point:
Who cares how the title attribute is rendered by a browser, when it is the presence of malicious strings in the source code that could present an issue?
It doesn't matter how it is displayed, the question is: how does it appear in the source code?
(As already stated, if you're pumping strings to the client, do something to sanitize those strings.)
I think there may be some confusion going on with this thread.
Firstly <asp:Label> is an ASP.NET Web Control. The Text and ToolTip attributes are "abstractions" of the inline content and 'title' attributes of an HTML tag respectively.
For these particular two properties Microsoft will perform the HTML Encoding for you automatically so if you set ToolTip="H&S<" then the <span> tag will be rendered as <span title="H&S<"...>. The same goes for the Text property.
NOTE: Not all properties perform automatic encoding (HTML or InnerContent properties for example)
If however you are generating HTML tags directly (Response.Write("<span...") for example) then you MUST http encode the text content and tooltip attributes content if:
Those values originate from a user / external unsanitised source or
If there is a possibility that the content may contain characters that should be escaped (& < > etc.)
Usually this means that it is safe to to:
Hardcoded content with no http characters:
Response.Write("<span title='Book Reference'>The art of zen</span>"); // SAFE
Hardcoded content with http characters that you manualle encode:
Response.Write("<span title='Book & Reference'>The art & zen</span>"); // SAFE
Dynamically sourced content:
Response.Write("<span title='"+sTitle+"'>"+sText+"</span>"); // UNSAFE
Response.Write("<span title='"+HttpUtility.HtmlEncode(sTitle)+"'>" +HttpUtility.HtmlEncode(sText)+"</span>"); // SAFE
I have an ASP.NET MVC application and I'm using CKEditor for text entry. I have turned off input validation so the HTML created from CKEditor can be passed into the controller action. I am then showing the entered HTML on a web page.
I only have certain buttons on CKEditor enabled, but obviously someone could send whatever text they want down. I want to be able to show the HTML on the page after the user has entered it. How can I validate the input, but still be able to show the few things that are enabled in the editor?
So basically I want to sanitize everything except for a few key things like bold, italics, lists and links. This needs to be done server side.
How about AntiXSS?
See my full answer here from similar question:
I have found that replacing the angel
brackets with encoded angel brackets
solves most problems
You could create a "whitelist" of sorts for the html tags you'd like to allow. You could start by HTML encoding the whole thing. Then, replace a series of "allowed" sequences, such as:
"<strong>" and "</strong>" back to "<strong>" and "</strong>"
"<em>" and "</em>" back to "<em>" and "</em>"
"<li>" and "</li>" back to ... etc. etc.
For things like the A tag, you could resort to a regular expression (since you'd want the href attribute to be allowed too). You would still want to be careful about XSS; someone else already recommended AntiXSS.
Sample Regexp to replace the A tags:
<a href="([^"]+)">
Then replace as
<a href="$1">
Good luck!
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.