We are designing a data capture process with many questions (using ASP.NET), which can repeat (e.g. enter all your vehicles). In rare cases this could be over 100 repeating groups.
Therefore I've stated that rather than having one huge form that we split the application into multiple forms, using logical points for page splits (e.g. personal details) in a wizard style.
However, there is debate within the team as to whether we should be using AJAX/Javascript to have a single form. Suggested approaches to this appear to be:
Load in all the steps in one go, and just use Javascript to toggle.
Load in step 1 and load the other steps using AJAX.
Submit the form using AJAX and load the next step using AJAX.
Option 1 to me defeats the entire point, as you'd end up loading a massive HTML tree - some of the pages can be large. This would be more acceptable if there was a small number of steps with very few questions on each.
Option 2 to me seems overly complex, plus if the user clicks the next button, can you guarantee the next page has loaded? Also, what happens if input from page 1 is required for page 2?
Option 3 seems doable, but I'd have though the response time of doing the AJAX processing would actually be slower than doing a standard form submit, as there would be more processing involved by the client browser. Also this approach is more complex than a standard form submit.
Do you think my approach is correct (standard form posts)? I've read that typically AJAX is used to enhance the functionality of a page, rather than trying to emulate multiple pages.
The Single Page Interface Manifesto talks about how you can build SPI web sites without losing bookmarking, Back/Forward buttons (history navigation) or SEO.
With regards to performance, this is something you can test. But if you go the AJAX route, you should provide an alternative for those users without Javascript. The extra work required may be enough to push the idea off the board.
To my mind, options 2 & 3 lie at ends of a spectrum. You can use AJAX to submit whatever information is required for the next step. Option 2 submits nothing. Submit the entire form, and you have option 3. You'll probably want something in between.
As for performance, there is some processing to be done (collect form data, data transmission, parsing, splicing the result into the document), but the browser will be doing the same tasks with a traditional form; AJAX just makes parts of the process more visible. Since the data is smaller in size (part of a form rather than a full page), performance shouldn't be much worse and may in fact be better. Also, modern javascript engines are very fast.
In any case, listen to MikeB's advice about degrading gracefully when JS isn't supported, unless this is for an internal app where you can depend on browser make & configuration.
Related
I am building my own GridView in an ASP.NET project
I am drawing out my plans and I was wondering what the best solution is to a simple problem, paging and sorting.
The fast and easy way is using submit buttons (or similar) and POSTING the form back. That's also how the ASP.NET gridview works.
pro:
less overhead
con:
backbuttons
The second method is using links and the URL with GET requests.
pro:
backbuttons work just fine
direct link to certain position
con:
less reusable because of the dependence on url
The third method is AJAX
pro:
little overhead
con:
harder to implement
What design/solution would you pick and why?
Am i overlooking some pros and cons?
I add some extra comments to think about.
-The second method is using links and the URL with GET requests.
This is the one that you need to use, if your need web spiders (google) knows all the pages of your site, and be SEO friendly. This method have the problem that you can not have viewstate and each time you must render the page that you see on the url parameters with out knowing anything else.
With this case you probably have more problems if you wish to make edit on one line
-The fast and easy way is using submit buttons (or similar) and POSTING the form back
This is the method if you won to have many functionality on code behind because with the post back you have all the previous action that you have done, and the viewstate is working and can be used for that. Is not SEO friendly and if you like to make it you need extra code to write on the url just the page that you are now and need to land.
-The third method is AJAX
This is the method that must co-exist with the previous and not alone for the case that the browser fails to run javascript for any reason. If you do not care about that, the rest is that this method is also not SEO friendly and you need to make it, is cool, modern, and is a must for modern site, but if you going to make difficult things then you may end up with many issues that must be solved.
To summarize:
More than show data ? Post Request : Get Request ; // ToDo: make it ajax
At the moment we have a solution which is Web forms ASP.Net 4.0. We do a number of things such as using web methods and services either calling them using the standard web forms way or sometimes to reduce the footprint directly calling them with jQuery ajax posts and gets.
We are looking to improve the way we work but we have heavy constricts regarding how the solution is at the moment and not being able to completely rewrite it.
Updating the page using Ajaxs for data, forms and for example pulling "the next 20" items and displaying them on the page it what I would like to heavily stream line.
Using template's due as PURE and jQuery Templates is fantastic way to produce fast calls back and forth between the servers but results in having two copies of the html. (the template for the jQuery and the code in the actual first render of the page)
We have thought about possible producing a empty template and then always populating it via json data we post down to the server but I feel this isn't how things should be done...
can anyone reckoned the best way we can do this without having two copies of our 'template' (e.g. a row of a table)
You mean you have a template in asp and the same template in javascript, but you'd rather just have 1 or the other?
I think that is really subjective. It is always different based on use case. That being said I'd do it by modifying my views and templates. My views (non-js) would simply have containers for that dynamic content. In other words I'd never load the dynamic portions of content into the views initially. Rather, on page load I would simply load up the template and the json that fills it in.
If you think about it that's 2 more requests, but it makes your life easier. The user also is able to see something on the page sooner.
This is one of those questions that really depends on what you are doing. There are trade-offs to be analyzed with every solution.
Using ASP.NET MVC: I am caught in the middle between rendering my views on the server vs in the client (say jquery templates). I do not like the idea of mixing the two as I hear some people say. For example, some have said they will render the initial page (say a list of a bunch of comments) server side, and then when a new comment is added they use client side templating. The requirement to have the same rendering logic in two different areas of your code makes me wonder how people convince themselves it is worth it.
What are the reasons you use to decide which to use where?
How does your argument change when using ASP.NET Web Forms?
One reason that people do that is because they want their sites to get indexed by search engines but also want to have the best user experience, so are writing client code for that. You have to decide what makes sense given the constraints and goals you have. Unfortunately, what makes the most business sense won't always seem to make the most sense from a technical perspective.
One advantage to server-side rendering is that your clients don't have to use javascript in order for your pages to be functional. If you're relying on JQuery templates, you pretty much have to assume that your page won't have any content when rendered without javascript. For some people this is important.
As you say, I would prefer not to use the same rendering logic twice, since you run the risk of letting it get out of sync.
I generally prefer to just leverage partial views to generate most content server-side. Pages with straight HTML tend to render a bit faster than pages that have to be "built" after they've loaded, making the initial load a little speedier.
We've developed an event-based AJAX architecture for our application which allows us to generate a piece of content in response to the result of an action, and essentially send back any number of commands to the client-side code to say "Use the results of this rendered partial view to replace the element with ID 'X'", or "Open a new modal popup dialog with this as the content." This is beneficial because the server-side code can have a lot more control over the results of an AJAX request, without having to write client-side code to handle every contingency for every action.
On the other hand, putting the server in control like this means that the request has to return before the client-side knows what to do. If your view rendering was largely client-based, you could make something "happen" in the UI (like inserting the new comment where it goes) immediately, thereby improving the "perceived speed" of your site. Also, the internet connection is generally the real speed bottleneck of most websites, so just having less data (JSON) to send over the wire can often make things more speedy. So for elements that I want to respond very smoothly to user interaction, I often use client-side rendering.
In the past, search-engine optimization was a big issue here as well, as Jarrett Widman says. But my understanding is that most modern search engines are smart enough to evaluate the initial javascript for pages they visit, and figure out what the page would actually look like after it loads. Google even recommends the use of the "shebang" in your URLs to help them know how to index pages that are dynamically loaded by AJAX.
I have several pages of my web application done. They all use the same master page so they all all look very similar, except of course for the content. It's technically possible to put a larger update panel and have all the pages in one big update panel so that instead of jumping from page to page, the user always stays on the same page and the links trigger __doPostback call-backs to update with the appropriate panel.
What could be the problem(s) with building my site like this?
Well, "pages" provide what is known as the "Service Interface layer" between your business layer and the http aspect of the web application. That is all of the http, session and related aspects are "converted" into regular C# types (string, int, custom types etc.) and the page then calls methods in the business layer using regular C# calling conventions.
So if you have only one update panel in your whole application, what you're effectively saying is that one page (the code behind portion) will have to handle all of the translations between the http "ness" and the business layer. That'll just be a mess from a maintainable perspective and a debugging perspective.
If you're in a team that each of you will be potentially modifying the same code behind. This could be a problem for some source control systems but one or more of you could define the same method name with the same signature and different implementations. That's won't be easy to merge.
From a design perspective, there is no separation of concerns. If you have a menu or hyper link on a business application, it most likely means a difference concern. Not a good design at all.
From a performance perspective you'll be loading all of your systems functionality no matter what function your user is actually doing.
You could still have the user experience such that they have the one page experience and redirect the callback to handlers for the specific areas on concern. But I'd think real hard about the UI and the actual user experience you'll be providing. It's possible that you'll have a clutter of menus and other functionality when you combine everything into one page.
Unless the system you are building a really simple and has no potential to grow beyond what it currently is and provide your users with a one page experience is truly provide value and an improved user experience and wouldn't go down this route.
When you have a hammer, everything looks like a nail.
It really depends on what you are trying to do. Certainly, if each page is very resource-intensive, you may have faster load times if you split them up. I'm all for simplicity, though, and if you have a clean and fast way of keeping users on one page and using AJAX to process data, you should definitely consider it.
It would be impossible to list too many downsides to an AJAX solution, though, without more details about the size and scope of the Web application you are using.
Stackoverflow members,
How do you currently find the balance between javascript and code behind. I have recently come across some extremely bad (in my eyes) legacy code that lends itself to chaos (someHugeJavafile.js) which contains a lot of the logic used in many of the pages.
Let's say for example that you have a Form that you need to complete.
1. Personal Details
2. Address Information
3. Little bit more about yourself
You don't want to overload the person with all the fields at once, so you decide to split it up into steps.
Do you create separate pages for Personal Details, Address Information and a Little bit more about yourself.
Do you create controls for each and hide and show them on a postback or using some update panel?
Do you use jQuery and do some checking to ensure that the person has completed the required fields for the step and show the new "section" by using .show()?
How do you usually find the balance?
First of all, let's step back on this for a moment:
Is there a CMS behind the site that should be considered when creating this form? Many sites will use some system for managing content and this shouldn't be forgotten or ignored at first glance to my mind.
Is there a reason for having 3 separate parts to the form? I may set up a Wizard control to go through each step but this is presuming that the same outline would work and that the trade-offs in using this are OK. If not, controls would be the next logical size as I don't think a complete page is worth adopting here.
While Javscript validation is a good idea, there may be some browsers with JavaScript disabled that should be considered here. Should this be supported? Warned about the form needing Javascript to be supported?
Balance is in the eye of the beholder, and every project is different.
Consider outlining general themes for your project. For example: "We're going to do all form validation client-side." or "We're going to have a 0 refresh policy, meaning all forms will submit via AJAX." etc.
Having themes helps answers questions like the one you posted and keeps future developers looking in the right places for the right code.
When in doubt, try to see your code through the eyes of someone who has never seen it before (or as is often the case, yourself 2 to 3 years down the road), and ask yourself: "Based on the rest of the code, where would i look for this function?"
Personally, I like option number 3, but that's just because it fits best with the project I'm currently working on and I have no need to postback or create additional pages.