on my webpage the user must select out of a radio button list/dropdown list of types of computer locations - i.e. network share, FTP, HTTP. I want a different popup to come up for each option in the list, and in that popup will be some input fields to enter the network path, FTP address/username/password, HTTP url etc. I'm guessing I can use AJAX for this?
Thanks
If you're going to use AJAX to accomplish this, a good starting point is to make it work without JavaScript enabled. This may sound counter-intuitive, but it will mean that you have to write all the code which renders and handles the forms based on the submitted information. If you do this in a modular way, it is then a simple matter to add in the AJAX functionality to request and submit the forms, and you will know that your solution degrades gracefully as well.
AJAX is one approach, though for simple forms it might be easier just to to render them all and hide them, then show the one you want the user to fill in.
Related
Why do I need script on an aspx page?
Javascript will allow you to perfrorm client side coding, so to avoid having to post back to the server.
From Using JavaScript Along with ASP.NET
Working logic and application
processes on the client-side allows
browser based applications to seem
more responsive and to have more
"snappiness" to them.
For client scripting, i.e. validation. There are many scenarios where you need to execute certain logic on the browser's end.
Javascript runs on the client side. So if you want anything to happen or change without refreshing the whole page you use javascript.
There are a lot of things the server can't really do that well. For example if you want to manipulate the page. You could post the whole thing back to the server with some sort of action and get the server to give you a new page. Or you could just use javascript to change it for you and avoid the trip to the server. It is faster for the client and takes the load off of your server.
It helps in doing things on the client side, which essentially means you can :
reduce burden on your server
by doing less postbacks.
do a round of validations on the client
side itself if they are non critical.
Do some fancy stuff like animations etc with out contacting the server
There are a lot more implications/uses of using JavaScript.
For knowing more, remember google is your friend!
Thanks
I'm not sure if you mean why ASP.NET pages requires Javascript, or if you mean additional scripts on the page.
ASP.NET uses Javascript for several types of postbacks. If you for example have a LinkButton, a script is making a postback instead of the default action of the link.
You can use additional scripts on the page for visual effects and to verify data before doing a postback to prevent unneccessary postbacks. (Of course you should also verify the data on the server side to protect against malicious actions.)
In Asp.Net, what control is more suitable for getting time (hh:mm) from user and pass it as a parameter to a query?
If you don't mind using the ASP.NET Ajax Control Toolkit, you can use the MaskedEdit control. The second example shows you how to let users enter a time-value.
I believe you have to choose between the following three:
Use a TextBox and do extensive input validation.
Use solution #1, but add a client side time picker on top of the TextBox.
Use two DropDownList controls - one for hours, one for minutes.
Use some kind of third-party time picker control.
Which one is better? I would say, that depends a lot on the expected users of your application. Anyone used to working with a keyboard is likely to prefer the TextBox. Others might prefer the other options. For the broad masses, I would most likely go for solution #2, as it should suit both keyboard and mouse centric users.
If you choose to go with a third-party control, be wary that it might not degrade gracefully for users that do not accept Javascript. The control might just revert to a simple TextBox, possibly without any validation logic.
I have a wizard style interface where I need to collect data from users. I've been asked by my managers that the information is to be collected in a step by step type process.
I've decided to have a page.aspx with each step of the process as a separate user control. step1.ascx step2.ascx etc...
The way it works now, is that when the initial GET request comes in, I render the entire page (which sits inside of a master page) and step1.ascx. When then next POST request comes in for step 2 (using query string step=2), I render only step2.ascx to the browser by overriding the Render(HtmlTextWriter) method and use jQuery html() method to replace the contents of a div.
The problem with this whole approach, besides being hacky (in my opinion) is that it's impossible to update viewstate as this is usually handled server side.
My workaround is to store the contents of step1.ascx into temporary session storage so if the user decides to click the Back button to go back one step, I can spit out the values that were stored for it previously.
I feel I'm putting on my techy hat on here in wanting to try the latest Javascript craze as jQuery with .NET has taken a lot of hack like approaches and reverse engineering to get right. Would it be easier to simply use an updatepanel and be done with it or is there a site with a comprehensive resource of using jQuery to do everything in ASP.NET?
Thanks for taking the time to read this.
Another approach, that might be easier to work with, is to load the entire form with the initial GET request, and then hide all sections except the first one. You then use jQuery to hide and show different parts of the form, and when the final section is shown the entire form is posted in one POST to the server. That way you can handle the input on the server just as if the data entry was done in one step by the user, and still get the step-by-step expreience on the client side.
You could just place all your user controls one after another and turn on the visibility of the current step's control and turn on other controls when appropriate . No need to mess with overriding Render(). This way the user controls' viewstate will be managed by the server. and you can focus on any step validation logic.
Using an UpdatePanel to contain the steps would give the ajax experience and still be able to provide validation on each step. If you are OK with validating multiple steps at once, Tomas Lycken's suggestion (hide/show with JQuery), would give a fast step by step experience.
Did you look into using the ASP.NET Wizard control? It's a bit of a challenge to customize the UI, but otherwise it's worked well for me in similar scenarios.
I need to read data from an online database that's displayed using an aspx page from the UN. I've done HTML parsing before, but it was always by manipulating query-string values. In this case, the site uses asp.net postbacks. So, you click on a value in box one, then box two shows, click on a value in box 2 and click a button to get your results.
Does anybody know how I could automate that process?
Thanks,
Mike
You may still only need to send one request, but that one request can be rather complicated. ASP.Net is notoriously difficult (though not impossible) to screen scrape. Between event validation and the ViewState, it's tricky to get your requests just right. The simplest way to do it is often to use a sniffer tool like fiddler to see exactly what the http request looks like, and then just mimic that request.
If you do still need to send two requests, it's because the first request also places some state in a session somewhere, and that means whatever you use to send those requests needs to be able to send them with the same session. This often means supporting cookies.
Watin would be my first choice. You would code the selecting and clicking, then parse the HTML after.
I'd look at HtmlAgilityPack with the FormProcessor addon.
I've always wondered what is the best way to add a new item to html-select in a website.
Yes, this may sound silly but it is a great problem from the usability perspective. I don't want the user to be taken to a new page every time they need to add new item to a html-select.
I like the way Google Reader and Gmail handle this problem in there "add folder" and "add label" functionality. I would like to mimic that but i have no clue how they did that.
I'm using jQuery, so any reference to plugins, code examples or tutorials are welcome.
I would like it to be as modular as possible so i can reuse it anywhere.
I'm using ASP.NET 3.5 web-forms, Microsoft Access 2003, jQuery, IIS 5 and Win XP Professional as web server.
Thanks.
there's a jquery select plugin that might help you with this. I've manipulated select lists client side and had no problem with subsequent form-submits but you'd need to do some experiments w asp.net
The standard technique of doing this is called ajax, which basically means replacing only parts of the page. JQuery ajax and maybe a tutorial should get you going.
A common mistake for this scenario is to add the item on client (using jQuery or plain javascript). It may look that it works until the next post-back. Unfortunately the Asp.NET post-back model does not allow to alter the controls contents on client side only. So basicaly there are two choices:
Use ajax (the simplest would be to
use an UpdatePanel)
Make a normal
postback to add the item (simple and
fast to code, if performance is not
an issue - for intranet applications
for example)