I intend to build a web application where users can enter their time every week and have been struggling to get my head around the concept of a single page in GWT that gets repainted with data depending on the user actions. After researching a lot on this site and google, I found one link that I would like to emulate but dont know how to go about doing it in GWT. Although their source code is available, I dont think it is full and complete. I got some idea from this link - Multiple pages tutorial in Google Web Toolkit (GWT) but again dont know how to implement it into a working version. One small working sample would be great to help me understand and get started.
Could anyone please guide me as to how to achieve the look and feel of the screen with the link below and how the content can be repainted with data from the server ? Would I need to put all the logic in one EntryPoint class ? I would like to have the hyperlinks in the left navigation panel and show the content in the right panel. I seem to be completely lost after a few hours of research.
http://gwt.google.com/samples/Showcase/Showcase.html#!CwHyperlink
Thanks a lot for your help.
Regards,
Sonu.
A single page application layout is actually quite easy to achieve.
The first thing you do is define the general layout, using GWTs layout panels. For your layout, I'd suggest using a DockLayoutPanel.
Content content = new Content();
Button switchContent = new Button(content);
Navigation navigation = new Navigation();
navigation.add(switchContent);
DockLayoutPanel pageLayout = new DockLayoutPanel(Unit.EM);
p.addWest(new HTML(navigation), 7.5);
p.add(new HTML(content));
Here, the width of the navigation panel will be fixed, whereas the content will take the remaining space. You have to pass a reference of the button (or some other widget) which does the switch of the content area, add the button to the navigation area, and so on.
Put this into a class, e.g. called MasterPageFactory:
public class MasterPageFactory {
private MasterPageFactory() {}
public static MasterPage newInstance() {
Content content = new Content();
Button switchContent = new Button(content);
Navigation navigation = new Navigation();
navigation.add(switchContent);
DockLayoutPanel masterPage = new DockLayoutPanel(Unit.EM);
masterPage.addWest(new HTML(navigation), 7.5);
masterPage.add(new HTML(content));
return masterPage;
}
}
Now, in your EntryPoint class, call the factory:
RootLayoutPanel.get().add(MasterPageFactory.newInstance());
This example should get you an idea. Other options would be using a DI framework like Guice or the Command pattern.
Your question is mixing up a couple of concepts. If you want the user to click something that looks like a link, and in reponse the application sends a request to the server and shows a page that looks different than the page they're on, and that page has fresh data that just came from the server, then you want a perfectly normal anchor or form submit button. You don't need anything special or weird from GWT.
The showcase example you referenced lets the user click something that looks like a link, and looks like it loads a new page, even to the point of letting the back button work as expected, but does not actually hit the server to get a new page or new data.
Related
experts,
These are two very basic connected questions.
I'm studying SAPUI5 and I cannot find means to position my UI elements on the screen.
In my view.js file I create, let's say, a button, a datepicker and a text field.
If I do something like:
aControls=[];
<Define the button - oButton>
aControls.push(oButton);
<Define the datepicker - oDatePicker>
aControls.push(oDatePicker);
<Define the text field - oText>
aControls.push(oText);
return aControls;
then I get all three elements positioned in a row one right after another.
I cannot use css, because I pass all those objects in one array and all of them are placed into a common div on index.html.
How do I position these? A link to any good tutorial/examples is very welcome.
Also, how do I refresh UI elements?
For example, I have situation, when on button press I make a call to the server, get response and put it into a using something like:
response.placeAt('some-id');
The button is created in the view.js and the call is processed in controller.js.
The response is added every time I press the button and I have no idea how to replace the old response with the new one.
A good link is very welcome.
Thanks.
There are a lot of layout controls of SAPUI5 you can use: Grid, HorizontalLayout, VerticalLayout, MatrixLayout,etc. You can check the examples and see how you need to layout your views.
You are currently doing UI5 JS view which implements createContent method to define views, this is one approach. Another common approach is to use XML views, it is declarative and more straightforward, also needs less code. See this simple example in JSBin of defining XML view and controller to refresh UI.
SAP UI5 is all about Model(JSONModel/ODataModel)-View(JSView/XMLView)-Controller. You are highly recommend to read this MVC example, though it is based on SAP UI5 mobile, the content is relevant to SAP UI5 desktop as well.
Hope you will get some hints.
We use MVP with custom EventBus to navigate across the views. One of our GWT module loads an ebook within a view. We have a button named "Expand", which upon clicked, loads the ebook in expanded mode thereby hiding the header, footer, etc.
Let us say the view (UiBinder) with "Expand" button is named as "ShowEbookView". Upon clicking "Expand" button, the ClickEvent is captured and fired to the EventBus. The logic onExpand(final ExpandEvent expandEvent) is written in the same "ShowExpandedMod" class.
Everything is okay, but we have a button named "Popout" in the expanded mode, which when clicked, should open the Ebook in a NEW page! We need to abstract the "ShowExpandedMod" class so that it can operate with the EbookId and can be used in the new page.
We have created a new Module with EntryPoint class, HTML page and UiBinder page for this new popout window. I am not sure how to proceed now with the abstraction and to use EventBus across different modules to load the same content ... (with re-usability ofcourse)
I've explained to my best, but perhaps not very clear! Please let me know if you want more details.
Thanks!
When you open a new window in browser you basically get a new instance of your GWT app. You can not use EventBus across different browser windows, i.e. across different GWT module instances.
What you can do is:
Add an argument to the Popout page URL. This is easies done via "history tokens" (fragment identifiers), like this http://yourdomain.com/popout.html#theIdOfTheDocument. Then you can retrieve the token via History.getToken()
Use DOM to communicate between browser windows: window.open() in javascript opens a new window and returns a reference to DOM of the new window. You can then access properties and functions of the new window. This is all javascript, in order to make this work in GWT you'll need to wrap it in JSNI.
Try and use MVP4G, in specific - take a look at their multi-modules feature (which utilizes GWT's code splitting capabilities).
This should make things like multiple EventBus's and cross-module event triggers a lot easier to handle.
Before you start shooting me down i have checked for answers and i have googled till my fingers bled but i havent been able to find a simple, concise answer. So im asking again for all those that might have this problem.
Question: how to open a new window with a formpanel in side.
Context: i have an app that lists lots of items, i want someone to edit an entry, i want a new window to open so they can edit properties then hit save. A standard thing you find in a lot of applications.
Architecture:
I have one client module called UI, it has a dozen classes that draw widgets and fill a main area when selected from a menu. I have a single html page called UI.html which has the tag in the head. Thats it.
Options Ive Seen
Call Window.Open() but you need to define a html file. I dont have one. I can create an empty one but how do you inject a widget in to it ?
use jsni $wnd to create a new window and get a reference to it. But how do i inject a form panel into it ??
use a popuppanel. They look sucky - plus if opening a window through JS is quite simple i would expect it to be in gwt.
Maybe im miss understanding how to use GWT i dont know.
Any help would be appreciated
Thanks
The way i got this to work is as follows:
i wrote a jsni method to open a new window
public static native BodyElement getBodyElement() /*-{
var win = window.open("", "win", "width=940,height=400,status=1,resizeable=1,scrollbars=1"); // a window object
win.document.open("text/html", "replace");
i added a basic body to the new window and returned the body element
win.document.write("<HTML><HEAD>"+css1+css2+"</HEAD><BODY><div class=\"mainpanel\"><div style=\"width: 100%; height: 54px;\"><div id=\"mainbody\"class=\"mainbody\" style=\"width: 100%;\"></div></div></div></BODY></HTML>");
win.document.close();
win.focus();
return win.document.body;
}-*/;
i then called this method from my main java method
BodyElement bdElement = getBodyElement();
I then injected my panel which has lots of widgets into the returned body element
SystemConfiguration config = new SystemConfiguration(); bdElement.getOwnerDocument().getElementById("mainbody").appendChild(config.getElement());
I agree with Bogdan: Use a DialogBox.
If you can't, you Window.open() as you mentioned in option 1:
Create another GWT module, and form.html that will load it
Window.open("form.html?entry=54")
Have the form gwt module read from the URL, load the entry, allow it to be edited, and provide Save and Cancel buttons
Close the popup when Save or Cancel is clicked
Can't you just use a DialogBox?
Example
I'm sure there's a simple answer but I can't think of it.
I'm working with a designer who is using Dreamweaver to produce a series of static HTML pages and style sheets. These pages navigate to each other using standard anchors.
However, on a couple of pages there needs to be a navigation to a page under ASP.NET.MVC 2 (from here I do all the coding stuff to the backend) which has Form input etc.
What is the best way to ...
1: Navigate from a standard HTML page into ASP.NET.MVC 2(Home controller)
And/Or
2: The best way to have ASP.NET.MVC output the static HTML pages. Meaning the ASP.NET.MVC controller reads the static HTML (from a cache) then outputs it to the View
Hope this makes sense, thanks in advance.
Any links will be very much appreciated
If you're going to the root of an MVC-based site, if would just be the URL as the index view of the home controller is usually the default. Something like http://www.website.com. However, if you want a specific controller/view then the the syntax would be http://www.website.com/{controller}/{view}.
HTH
im new to GWT ive been working on it since recently..
i want to know how can i go from "entry point page" ie,ImageViewer.java..
ive been suggested to create the memory by calling constructor on a perticular button
Button button = new Button("New button");
button.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event)
{
new LookupMaster(); //this is a composite
}
});
but this is not working.. i guess v can only call or get alert messages using this type..
can some one help me.
I'm not sure how to answer, since I have the feeling you're not understanding the basic concepts totally, but that's just my interpretation.
GWT is one html page that via JavaScript methods changes the content of that one page. When you want to display 'another' page you need to do this via methods that update the html dynamically. Since you are just starting with GWT, you might want to read this page on Build User Interfaces to understand the concepts and look at some examples provided with GWT.