I think what you are trying to do matches a couple of projects I've done in the past (one with GWT).
I think GWT will just give you a very nice set of user controls and a solid way to implement your client side code. There are more complete frameworks/application for what you are trying to do. I'll try and dig out some links. Off top of my head would something like http://metawidget.org/ be useful? Not sure if you said what your server side technology would be. RDBMS, Java...? Some unsolicited advice (always popular ;) if you don't have an existing way to model your forms etc adopt something standard like XML or SQL (meta data). That way you will get some free tools. Maybe have your non-tech users designing the forms in XML Spy or something like that. If your rules and validation get complicated quickly it might be worth jumping to JavaScript as the expression language. Even if you provide a nice UI on top of this at least you will have a Turing complete engine at the outset. Being in the browser XML and JS work nicely although not so great if you back end is a RDBMS. Hope that helps. Sounds like a nice big fun project. Cheers Sam On Aug 5, 6:27 pm, "A.Augustini" <[email protected]> wrote: > Hello Sam: > > First of all, thanx a lot for your reply. > > > If I had similar spec to you (complicated interactive registration > > that needs to happen on the client) then GWT seems like a good fit. > > Yes indeed, your spec is comparable mine: I've to build an *ordering > form* with "injected" rules, which are *dynamically specified* by an > admin via an Online Admin Module. These specifications are then stored > in my backend database. > > > Depends a bit how often your registration fields and rules change. If > > it is not very often then expressing them in Java (compiled to > > JavaScript) seems much > > the best way. Then you can write unit tests and use Java tooling... > > Once defined, the fields and rules don't change very much. The issue > is that fields & rules must be programmable by a non-technical enduser > (the admin mentioned above). -- So *Java* would't be very appropriate > for this enduser-programming case; the idea is to offer admins a > *declarative* method for specifying the form components and their > behaviour in a textual (or better graphical) manner. > > > I've written the other extreme (UI to add fields, config > > validation...) and it is a big task. > > It seems that this goes in the same direction (???), assuming that you > have a graphical form composer and one kind (?) of rules, namely > *field validation rules*. > If your scenario is comparable to mine, could you please outline which > GWT app components are in place and which responsibilities > (collaborations) they have? I think this would help me a lot at the > moment. ... And I would be very thankful for that. > > @all: I also would very much appreciate some other suggestions/ideas > if there are any among you more experienced GWT users. > > Thank you very much in advance. > > Best regards, > Alessandro > > > > > On Aug 3, 12:36 pm, "A.Augustini" > > > <[email protected]> wrote: > > > Currently learning GWT, and I still cannot imagine how to build a > > > *rule-based* controller for a dynamically composed form -- preferably > > > a multipage one, and -- due to GWT concepts -- obviously running on > > > the client side in JavaScript. > > > > The idea is to have a multi-sections/multi-tabs registration form > > > that: > > > (a) shows its questions according to "question specs" from a > > > backend database, > > > (b) gives the users instant input validation feedback via locally > > > centralized validation rules base, > > > (c) controls the "questionary behaviour" after some locally > > > centralized "fill out" rules, e.g., > > > > * "When user fills out InputField A, hide section/tab C". > > > * "When user checks CheckBox B, also check boxes Y > > > and Z automatically". > > > * "When user selects D,E and F then show {widget} G". > > > * ... > > > > (d) finally submits all the collected data (from each form page/tab) > > > to a server-side service (i.e. 'submit' button triggers RPC). > > > > The main point is to optimally have all the validation, filter, > > > action/ > > > behaviour, etc. rules centralized at one place -- hence the rule-based > > > approach. > > > > The main issues are: > > > 1. Which way to go for realizing such a "JavaScript Rule Engine" > > > solution in GWT? > > > > 2. Does there already exist a GWT framework or Composite targeting > > > *rule-based* form controllers for the client side? > > > > Hope some more experienced GWT programmers can help me further on > > > this topic. > > > > Kindly regards, > > > Alessandro -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
