Share data between Activities/Presenters in GWT - gwt

II want to share data between Activities (which are my presenters) without passing the data with the Place. How can I do that?

If the data really isn't all that large I'd try and encode it in the Place: then your users can bookmark/distribute URLs that lead right into the guts of the application (link to a specific product, search filter, etc).

Quite some ways. A simple way is -
you could create a public static field in some class and use that in all of your presenters . (This method obviously has strings attached and must be used carefully)
Jai

Related

Implement the Lead conversion using custom button

I will need to create a Custom Button "convert lead" that will perform the same functionality as Standard Button "Convert" when the button is clicked.
What is the best approach to do it..?
That's a very broad question. What exactly you need, what have you tried so far? Do you really need just a button that opens the conversion page or something more?
If you want to somehow recreate it with Apex... Core of the coded solution would be the Database.convertLead method. You don't pass to it whole leads (like to Database.insert for example) but instead just their IDs + bunch of control flags to make it do exactly what you need. Read up about LeadConvert object. And similarly you can get Account/Contact/Opportunity ID from the result object if it succeeded.
I don't think there's programmatic way to access field names & mappings defined by administrator for lead conversion. Maybe you'd need to store this info somehow (in helper object? custom metadata?). So then you'd query the field names from metadata, then query the lead fields and finally display table of fields & mappings to the user.

Ionic 2: where to store app wide static strings and messages

Where can I store app wide error messages or static strings?
Currently I'm using Providers. Does we have any better way of doing this?
Exporting one class for storing all your constants would definitely be an option I'd say.
However in case your speaking of error messages or generally text being rendered and displayed in your app, ng2-translate would be an option. Even when you're not planning to publish your app for different languages, ng2-translate has several advantages, as you can store text for different parts of your app in different json files, allowing you to easily structure your text constants.
Also you do not need to load all your translations at once but have the possibility to require them when you really need them - so load the texts when you navigate to a particular route in your app instead of loading all of it on startup.
However - I'm assuming here, that you're speaking of messages or page content and not string constants you're using programmatically somewhere. In this case I'd say stick to your initial approach and export a class containing your constants to keep them in one place:
export class AppConstants {
public static get API_ENDPOINT(): string
{
return 'http://some.url/api/';
}
}

Is it OK to Move Common ViewController Presentation Logic into Presentation Helper Classes

I'm trying to use layers to make sure I separate everything into it's correct areas in my Swift / iOS / Xcode 6 project. The question, ultimately, is: is it OK / a common practice to move commonly used presentation-level logic to a separate presentation helper class instead of writing it over and over in multiple view controllers with little or no difference?
Here is an example to tie this in and give context:
One of the things I am aiming to do is use a UITableView to display report data. This UITableView will contain 7-10 rows, depending upon the user's preferences (nsuserdefaults). Each row contains a localized string for a label, and some decimal value.
As an example one row could be "Sales made this week: $500.00"
I have a reporting service class that's responsible for talking to the database and getting back / instantiating a report object. This report object contains the raw data for the report, i.e. how much you made this week, this month, this year, etc. Whether the user wants to show all these values or not is irrelevant to the service - it simply gets everything.
So since I have 3 view models that use this same report, I thought it would be wrong to rewrite the same code each time that checks the user's preferences, then creates/binds an array to the UITable and matches the labels with the report values from the object returned by the service.
A better way, I thought, was to create a presentation-level helper class whose job would be to take a report object (the thing I mentioned before that contains the report values), take a user's preferences, and then more generically combine them to create a list of localized strings matched with their respective report values, agnostic to what the view controller wants. Maybe if that requirement changes later (where different view controllers need more customization) I could use flags or different function names within that class.
This way all I have to do is something like
var report = ReportHelper.GenerateReport(reportData, userSettings)
and now report would be an object that could look like this (mock JSON data):
{"Amount made this week":"$100", "Amount made this month":"$500", "Amount made this year": "$10,000"}
And I can use this in any view controller.
The alternate is to just hard code those above values (obviously still pulling localized strings) but I don't know if I adding all those strings + checks based on user preferences + formatting. Seems more elegant to move it away.
Thanks!
I know too little about your problem to provide the definite answer, but basically you have 2 options:
- inheritance
- composition
I personally like inheritance although it is often stated you should choose composition over inheritance.
Your helper sounds somewhat like composition, so that would be the preferred setup. With your specific problem as I understand it, inheritance would lead to a duplication of data, so that is one more argument to choose composition.
So all in all you seem to be about right
Edit:
Inheritance is an "is" relationship, whereas composition is a "has" relationship.
See http://en.wikipedia.org/wiki/Object_composition for more details about composition.
And see http://en.wikipedia.org/wiki/Composition_over_inheritance for more info why and when to choose composition

GWT Client Server Communication

I'm wondering whether it is at all possible to make the client ask the server for a given string, and incorporate it into another string ?
I don't see how to do that using the async approach.
As far as I know there is no really simple way to do this, because the i18n machanism of GWT replaces strings at compile-time and not at runtime.
You can try one of the following approaches:
Load the i18n in your entrypoint, store all messages in a local Map and create the Label etc, with the values from you cache. PRO: all GWT standard CONS: one request more, before you can show a translated page
Use JSP and no HTML at serverside. Wthin you jsp can create a JSON from your
message.properties and put it into your hostpage. PRO: You can synchronous read te values CONS: You will need to write a JSP which reads the properties for the correnct language, You will need to write a JSNI method to load the translated values.
Rethink, if you need a different way of translation. The built-in i18n will create tranlated versions of your app at compile-tim
I think I would use the second approach.

automatic GWT ClientBundles based on disk files

I'm currently making good use of GWT's ClientBundles in my app. It works fine, but I have a large number of resources and it becomes tedious to manually create Java interfaces for each file:
#ClientBundle.Source("world_war_ii.txt")
public ExternalTextResource worldWarII();
#ClientBundle.Source("spain.txt")
public ExternalTextResource spain();
#ClientBundle.Source("france.txt")
public ExternalTextResource france();
I'd like to be able to (perhaps at compile time) dynamically list every *.txt file in a given directory, and then have run-time access to them, perhaps as an array ExternalTextResource[], rather than having to explicitly list them in my code. There may be hundreds of such resources, and enumerating them manually as code would be very painful and unmaintainable.
The ClientBundle documentation explicitly says that "to provide a file-system abstraction" is a non-goal, so unfortunately this seems to disallow what I'm trying to do.
What's the best way to deal with a large number of external resources that must be available at run-time? Would a generator help?
There's an automatic generator for CssResource - maybe you could look at its code and modify it to your needs?
I ended up following this advice: perform the file operations on the server, and then return a list of the file (meta)data via an RPC call.
This turns out to be fairly simple, and also allows me to return lightweight references (filenames) in the list, which I use to populate a Tree client-side; when the user clicks on a TreeItem the actual text contents are downloaded.