Adding ASP.NET Server Side Controls Dynamically Like as Javascript - html

I have a simple aspx page.
In this page I want to add dynamically dropdownlist-textbox pairs that represent key-value pairs. But I dont know how much it is when page loading.
So I must add these controls to page dynamically(in runtime)
If I add these controls in codebehind 2 problems arise :
Page is reloaded in every appending because of autopostback. It couses blink.
Whenever page reloads, previous appending disappear.
If I add these controls in client-side(javascript) :
Controls cannot be reachable in codebehind(because no runat=server) so validation steps open to user(I think validation steps must operate in codebehind othervise this is an integrity problem).
What would be true approach about this problem ? Could give example ?

If you want to avoid the blink(page reload) you have to go for adding the control dynamically into your form using JavaScript.
Controls cannot be reachable in codebehind(because no runat=server)
This statement is not correct, you can always access your form control at server side using Request.Form collection. Check here for more details. You will be required to iterate over the contents of this collection to get the values.
I think validation steps must operate in codebehind othervise this is
an integrity problem
Validation you need to do by yourself before performing any operation. You might required to write some custom validation logic.

Related

CakePHP - refresh element/view cell using ajax

I'm trying to build a way to update a user profile one question at a time.
Essentially I want a div on my page that displays a form that lets the user submit the most important information, say firstname. When that has been filled out (success on the form) I want to refresh that div and show the second most important form, for say lastname, or if that is already filled in then birthday and so on.
Much like linkedin prompts you to add one more piece to your profile.
How would you do it?
My first thought was to use elements. But I need to fetch existing profile data to populate the form and how would the element get that data, abusing requestAction is not an option.
So I guess I in that case need to call a controller action that determines which element should be rendered, renders it to a variable and submits that (response->body) in json to the js that updates the page. Seems a bit .. unclean but should work.
Then we have view cells. They seem ideal for the task until I want to call them via ajax. That is not possible right?
So how would you go about to build something like that?
A form that needs to have the ability to be prepopulated with data if there is any and then refreshed automagically to display the form for the next piece of info needed.
View cells can't really be used in AJAX requests. This is not what they thought for.
The best thing you could do, if you want to keep the cell, is to make sure you followed SoC properly and put all your business logic into the model layer.
Now have a separate controller and action that is reachable from the outside throught a request (a cell is not) and return the data as JSON from there using the same code.
You could try to instantiate the cell in the controller action as well and send it's output. But honestly, I think that's a pretty fugly way of doing it.

Using either GET or POST depending on submit button

I have a web application for tagging data and viewing data by tag, so my UI is a list of checkboxes for each tag, a list of checkboxes for each data item, a "Tag" button, which adds the checked tags to the checked data, and a "Filter" button, which ignores the checked data and just displays only the data items with the given tag.
My problem is that the former operation (tagging data) is "obviously" a POST operation, whereas the latter operation (viewing data according to a tag) is "obviously" a GET operation. But the method attribute is attached to the form, not the submit button, so I have to choose one or other for both buttons.
I don't want to make two forms, since as far as I can tell this would force me to duplicate the entire tag list. Is there any way I can choose my method based on the choice of submit button?
A JavaScript solution is permissible, but one without would be preferred.
(I am going to post an answer to this question, but I don't particularly like it, so I would welcome alternatives).
In principle, you could use the formmethod attribute in a submit button, as per HTML5. However, it is not recognized by IE, even in IE 9. The existence of the feature in HTML5 indirectly proves that previous versions of HTML lack a feature for this.
On the other hand, the POST method can be used even for simple viewing that does not cause any changes in the outside world, and in many situations it has to be used for technical reasons (e.g., too much data). So I think the method issue is not very relevant; just use POST.
I would honestly go with a javascript solution, in the onsubmit of the form fire a method which a) checks the submit button that was pressed and b) based on this changes the method of the form.
One possible solution would be to use POST, and then have the server give a 303 See Other header to change it into a GET request. This involves making two requests to serve the purpose of one, which is unfortunate, but at least means that the URL will change so people can link to a specific tag selection.
I agree with javascript solution, proposed by Jon Taylor, the problem is not if your form's method is GET or POST, but how do you filter/validate/sanitize user input. If your concern is related to the fact, that the user can manipulate the form's method, then you should implement solution to that matter on server side.

Using a single shared element across multiple partial views

I have a basic ASP.Net MVC 3 application which has a number of controllers and a number of actions (and subsequently views)
A common feature of the application is to show a pop-up dialog window for basic user input. One of the key features of this dialog process is a faded mask that gets shown behind the dialog box.
Each of these dialog window controls is in a separate Partial View page.
Now, some view pages may use multiple dialog boxes, and therefore include multiple partial views in them - which as is would mean multiple instances of the "mask" element.
What I am trying to find a solution for is to only need to create one instance of a "mask" element regardless of the number of dialog partial views I include, and then the script in each partial dialog will have access to this element (so basically it just needs to be on the page somewhere)
The only real idea I have come up with so far is to add the "mask" element to the master page (or in the original view page) and this will mean it only gets added once. The problem here is that it will be added even when it is not needed (albeit one small single element)
I can live with this, but I would like to know if there is a better way to handle these kinds of scenarios?
A quick idea that came to mind is some kind of master page inheritance hierarchy, So I may have a DialogMasterPage that inherits from the standard current master page. How does that sound for an approach?
Thanks
To do something like this, where each module can register their need for a certain thing in the master page, you can use HttpContext to store a flag of whether you need to write the mask div, and just set that property in each partial. At the end of the master page, if the flag is set, you can then write the mask div if its set to true.
Obviously to make this cleaner you could wrap it all in an HtmlHelper extension or something.
My initial thought is for you to use something like jQuery UI where it handles the masking for you or if you are using something custom you can load the content for the dialog via ajax then show it in the single dialog on the master page.

Creating "are you sure?" popup window by using html only

Assume I have a html from, and it contain some submit type. I want to create a "are you sure" popup window that will appear when user click submit button.
My question is that is there any way to create it by using "only" html, not using javascript or any other?
HTML only is possible, but not without a postback
Scenario that could work without javascript:
You have your form with submit button
User clicks (and submits) the form
You display another form with are you sure? form (that contains Yes and No buttons as well as hidden fields of the first form that will make it possible to do the action required on the original data
functionality that executes the action and goes back to whatever required.
This would be completely Javascript free, but it would require several postbacks.
This kind of thing is usually done on the client with a Javascript confirm() function (here's a simple example) or lately with a more user friendly modal dialog provided by many different client libraries or their plugins.
When to choose the script free version?
If you know your clients are going to be very basic ones (ie. vast majority of your users will access your application using clients like Opera Mini that's not able to run scripts at all). But in all other cases it's much better to do this using Javascript. It will be faster, easier to develop and much more user friendly. Not to mention that it will put less strain on your server as well since certain parts will execute on the client without the need of any server processing.
No, there isn't. Despite of the new features in HTML 5, HTML is still a markup language, not a programming language. In order to express dynamic behavior (such as an "are you sure?" box), you need to use a programming language.
Javascript would be the most obvious choice for this, but you could also do it with frameworks that can get you around writing Javascript by hand (for example ASP.NET).
Edit: Actually it appears that it would theoretically possible to do this with without Javascript or other frameworks. As I just learned, HTML 5 + CSS 3 seems to be turing complete. But this is hardly relevant to this question.
It's possible to ask for a confirmation, but it will not be in a "popup window". The creation of the "popup window" requires javascript/other language.
It will be:
Request (first form)
POST
Response (confirmation form)
POST
Response (outcome message)
You can create a form with all hidden elements containing the data from the first form and a "Yes" and "No" button below the "Are you sure?" text. You can use PHP sessions to avoid the hidden form elements. If there is a lot of data or confidential data or you do not want to re-validate the data from the second form, use sessions. Make sure you validate the data from either form before using it.
I know I'm like .. 10 years late. But for anyone still wondering I thought I could be of some help!
What I did for this exact problem was make sure I had multiple "divs" in my code. For me specifically, I had two main ones.
First, one whose id="main", and another whose id="popup" with the 'visible' property initially set to 'false' for the popup div.
Then, on whichever event you're looking for (button click for example) you'll simply set main.Visible = false and popup.Visible = true, then you could have more buttons in your popup (yes, no, cancel, confirm, etc.) which do the exact same thing, but in reverse!
The most important thing to make sure of is that you have the 'runat="server"' property in your divs so that you can access them in your CS code
Hope this was helpful! :)

What is the attribute AlwaysEnableSilent used for?

I was looking at the raw HTML rendered by a SharePoint (2010) list item edit page, and I noticed that an input field (rich text field) made use of an AlwaysEnableSilent attribute. i have checked online for an explanation of what the attribute does, but have not been able to get a answer. Does anyone know what this attribute does?
Thanks, MagicAndi
ASP.Net validators allow you to turn them on/off using client side scripting using ValidatorEnable, but whenever you turn the validator on that way the validation fires immediately. Sometimes you (SharePoint) may want to be able to control which validators are active using client side scripting, but without the validation firing when you turn it on (during load, before the users have had the possiblity to fill out the fields).
In order to handle this SharePoint has defined its own function STSValidatorEnable with an extra parameter bSilent, so it can turn on validators without them firing.
They then found out that for some validators they always want them not to fire when STSValidatorEnable is called, even though the caller uses bSilent==false. So they introduced an attribute AlwaysEnableSilent which tells the validator never to fire when turned on using STSValidatorEnable, but only during postback.