Explicitly invoking FormAPI events

Hi,

Is there any supported way of explicitly setting an event for eg. onSave = true OR onSaveValid = true so that relevant event handlers may be invoked as and when desired? Any pointers please?

TIA

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curiousmaverick

Can you describe the requirement here? What do you actually need?

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Emanuel

Hi,

Is there any supported way of explicitly setting an event for eg. onSave = true OR onSaveValid = true so that relevant event handlers may be invoked as and when desired? Any pointers please?

TIA

I am taking a guess on this but (take this as pseudo code):

since this is how you attach events to handlers:
IWX.addhandler("item","event","handler");

function handler(item)
{
...
}

you can just call the handler as a normal function:

handler(IWX.getitem);

Is this what you needed?

Samir_Friend

My requirement is to set an event's state equal to true or false so that the function yyy that I have registered as IWX.addFormHandler("onSaveValid", yyy) may be invoked as and when desired. For example,

1. I registered a listener for the onSave event which invoked a function Foo.
2. When the processing inside Foo completes, I want to make an explicit call to another function FooYou. The FooYou function is registered for the event onSaveValid. I want to invoke the FooYou function by changing the onSaveValid event state to true.

In other words, I want to explicitly change the state of an event like onSaveNameSpecified etc so that the relevant event handler attached to it is automatically invoked. Does this make sense now?

Any method of doing this that you know of?

Emanuel

My requirement is to set an event's state equal to true or false so that the function yyy that I have registered as IWX.addFormHandler("onSaveValid", yyy) may be invoked as and when desired. For example,

1. I registered a listener for the onSave event which invoked a function Foo.
2. When the processing inside Foo completes, I want to make an explicit call to another function FooYou. The FooYou function is registered for the event onSaveValid. I want to invoke the FooYou function by changing the onSaveValid event state to true.

In other words, I want to explicitly change the state of an event like onSaveNameSpecified etc so that the relevant event handler attached to it is automatically invoked. Does this make sense now?

Any method of doing this that you know of?

You need to pass from Foo to FooYou trhough the event handler due to the parameters that gets attached to FooYou or else?

This is why he asked your requirements, not development ones, but functional ones EG: "...i need to set the name of a form before saving...".

curiousmaverick

The Save process actually involves several sub processes.The sequence of events involved is [color=red]onSave->onSaveValid->onSaveNameSpecified->onSaveDone.[/color]

Now if you registed a function with onSave,FormsPublisher validates the form. If the form is valid, the onSaveValid event is generated, and any registered user script function is invoked. And then it moves on to the next even.

There is an excellent flowchart diagram in the formAPI pdf explaining this. You may like to have a look at that as well.

Samir_Friend

Thanks Mav. I have gone through that diagram before asking this query.
My concern here is to find out a way to take control of generating the FormAPI events like onSave, onSaveValid etc. on will(as and when desired) in the flow.

I need to have the control to deal with the asynchronous nature of the callServer request.

Though I've already dealt with my requirement in some way or other, I am just curious to know if there's any supported method by which I can control the execution, generation of events and be able to change their state at will.

Let me know if something like that is possible.

Adam Stoller

Thanks Mav. I have gone through that diagram before asking this query.
My concern here is to find out a way to take control of generating the FormAPI events like onSave, onSaveValid etc. on will(as and when desired) in the flow.

I need to have the control to deal with the asynchronous nature of the callServer request.

Though I've already dealt with my requirement in some way or other, I am just curious to know if there's any supported method by which I can control the execution, generation of events and be able to change their state at will.

Let me know if something like that is possible.

I don't believe what you are asking for is possible. When you do a callServer (asynchronous operation) as part of any one of the chain-of-events, the handler from which you invoke the callServer must return false - at which time, the chain-of-events is terminated, and it is up to you to then "manually" perform any subsequent functions that were not run due to the termination of the chain-of-events.

Most often (in my experience) the event handler is set for onSaveValid in order to programmatically name the DCR. The callServer script is responsible for calling back to either an "ok" or "not-ok" function - the "ok" function would then perform a "save" and use a timeout loop to check to see when the save is completed (see the documentation on IWDCRInfo.getStatus)

Samir_Friend

I don't believe what you are asking for is possible. When you do a callServer (asynchronous operation) as part of any one of the chain-of-events, the handler from which you invoke the callServer must return false - at which time, the chain-of-events is terminated, and it is up to you to then "manually" perform any subsequent functions that were not run due to the termination of the chain-of-events.

Most often (in my experience) the event handler is set for onSaveValid in order to programmatically name the DCR. The callServer script is responsible for calling back to either an "ok" or "not-ok" function - the "ok" function would then perform a "save" and use a timeout loop to check to see when the save is completed (see the documentation on IWDCRInfo.getStatus)

My query is related to the same thing - manually invoking the event-handlers, checking whether an event is completed(state), if not, change the state and so on. I believe if I could just get hold of the FormAPI JS functions and variables(IW default), I could just make it, though it'd be kind of a "hack". Please let me know your thoughts on this one.

As far as autonaming is concerned, using the chain of events like onSave and onSaveValid, I found that the IWNameFactory is quite a useful alternate to get rid of the handlers as well as the Save Form As dialog(as per my requirement). I have used it my current implementation and also managed to deal with the asynchronous nature of the callServer request by some manipulation. Thank you all for your valuable inputs on this.

Bjorn

I believe if I could just get hold of the FormAPI JS functions and variables(IW default), I could just make it, though it'd be kind of a "hack". Please let me know your thoughts on this one.

Well, it wouldn't be "kind of" a hack at all. It would be a hack. That's not bad, necessarily, but it raises the question if you're willing to deal with the risks of doing something "unsupported".

Also, if you're doing all this to deal with the async nature of callserver()...then why not just not use callserver() and roll your own?

Mashuk

Hello,

Does anyone know how an event such as the onSaveValid can be explicitly called? I have a requirement, where I want to validate fields on the form when the Save button is pressed, so that triggers an onSave event. From reading the documentation the onSave event does not trigger the onSaveValid event if programatically called.

I want to explicitly trigger the onSaveValid event so that I can get a Save dialog box to appear, to enter the name of the DCR. Autonaming would have been preferable, but our users want to control the naming structure themselves so they need the Save dialog box.

Currently on TS 6.7.2 Linux

Any help much appreciated.

Thanks
Mashuk

Samir_Friend

Also, if you're doing all this to deal with the async nature of callserver()...then why not just not use callserver() and roll your own?

Well Bjorn, in that case, can you suggest an alternative to the callServer. Invoking a Perl script from Javascript seems to be not a simple task due to the limitations of Javascript. However, has someone tried it before? Any pointers?

Bjorn

Well Bjorn, in that case, can you suggest an alternative to the callServer. Invoking a Perl script from Javascript seems to be not a simple task due to the limitations of Javascript. However, has someone tried it before? Any pointers?

Sure -- keep in mind I'm only addressing the comment you made "I need to have the control to deal with the asynchronous nature of the callServer request". So you'll of course need to see if what I'm suggesting truly does fit into your needs. Smiley Happy

1 - Drop some sort of framework that supports ajax into the DCT. JQuery. Mootools, whatever you like. There are a thousand different ways to do this, actually, but they're all conceptually the same.

2 - Make sure to configure your Ajax objects to make your requests synchronous. Usually pretty straightforward. The risk is that the browser (FormAPI) hangs if the request hangs. The reward depends on whatever reason you had for being frustrated with having to deal with async requests of callserver() bumping into each other (or whatever).

3 - Use it to call your CGI (Perl script) to do whatever it needs to do. You may need to adjust your CGI to return something that is more "ajax-friendly", like XML.

This is pretty high-level. I could write some actual code or more specific instrux, but I'm not sure exactly what you need to do. Besides, half the fun is figuring things out on your own.

Samir_Friend

Sure -- keep in mind I'm only addressing the comment you made "I need to have the control to deal with the asynchronous nature of the callServer request". So you'll of course need to see if what I'm suggesting truly does fit into your needs.

1 - Drop some sort of framework that supports ajax into the DCT. JQuery. Mootools, whatever you like. There are a thousand different ways to do this, actually, but they're all conceptually the same.

2 - Make sure to configure your Ajax objects to make your requests synchronous. Usually pretty straightforward. The risk is that the browser (FormAPI) hangs if the request hangs. The reward depends on whatever reason you had for being frustrated with having to deal with async requests of callserver() bumping into each other (or whatever).

3 - Use it to call your CGI (Perl script) to do whatever it needs to do. You may need to adjust your CGI to return something that is more "ajax-friendly", like XML.

This is pretty high-level. I could write some actual code or more specific instrux, but I'm not sure exactly what you need to do. Besides, half the fun is figuring things out on your own.

Thanks, I'll do it myself. The whole idea looks cool, however, the implementation may not Smiley Happy

In my case, the IPL is supposed to parse an XML and return the extracted values to the parent JS by invoking parent.getScriptFrame() function. Pardon my ignorance but, if I try to implement the above idea, will my IPL be able to invoke the parent script's function? If not, it'll provide me with another resultant XML and I would be back to the same position where I started from.

Let me re-phrase the original situation once again:
I have a function X registered for onFormInit and another one Y for onSaveValid. The function X contains a call to the IPL using call-server. The IPL is supposed to generate a random name and pass it back by invoking a function Z of parent script. Z is supposed to set the name of the DCR and save it. The function Y is supposed to do some processing for other functionalities and then save the DCR.
When the form loads for the first time, X is invoked and so the IPL is invoked. When I fill the data and click Save or Finish, Y is also invoked if data entered in the DCR is valid. Invoking Y before the IPL finishes its execution(I don't know why the IPL is not able to finish the execution in such a long-time), leads me to a state when there is no name defined for the DCR and so I get a pop-up to provide a name to save it(which I certainly don't want since I want to autoname it). Thus, my concern was to synchronize the callServer method so that Y is executed only after the IPL finishes the execution.

I hope the above is not ambiguous. Any motivating ideas?

Bjorn

When the form loads for the first time, X is invoked and so the IPL is invoked. When I fill the data and click Save or Finish, Y is also invoked if data entered in the DCR is valid. Invoking Y before the IPL finishes its execution(I don't know why the IPL is not able to finish the execution in such a long-time), leads me to a state when there is no name defined for the DCR and so I get a pop-up to provide a name to save it(which I certainly don't want since I want to autoname it). Thus, my concern was to synchronize the callServer method so that Y is executed only after the IPL finishes the execution.

What I'm proposing isn't as much synchronization as conceptual "blocking", by way of making your call to the IPL a synchronous call, something you can't do with callserver() from FormAPI. Again, it has its advantages and drawbacks. The advantage is that your code will work; users won't be able to save the page if a name has not been set. The drawback is that it probably becomes more frustrating for users if your IPL takes as long as you're saying it takes. So maybe the best place to start is seeing if you can optimize your IPL as much as possible ... or eliminate it completely and use javascript to create the name.

In regards to scripting, change function X to use your custom server call. Have the IPL return XML specifying the generated name for the DCR. Process the XML obtained from function X and set the DCR name using the logic from function Z (you don't really need it to be a function anymore), something like this:


var xhr; //SOMEHOW GET XMLHTTPREQUEST OBJ
xhr.open("get","PATH TO YOUR IPL",false);
//maybe use IWDatacapture.displayMessage(""); to inform user that info is loading...
xhr.send(null);
if (xhr.readyState == 4 && xhr.status == 200){
   //USE xhr.ResponseXML to get value and FormAPI to set DCR name
   //USE FormAPI to save the form
}
//don't forget to add your own error handling, etc...

With this code above, the page will sit tight until it gets a response from the request. A user cannot not save the page from the UI until the DCR name is set. If this takes a long time, the users won't like it because it will have looked like the page has "frozen". You could add a message saying the form is loaded, as suggested in the code above.

If this doesn't meet your requirements or the users' fancies, then you'd have to look at something like keeping the request to the IPL asynchronous and adding a check for a DCR name to your form validation (onSave?) and returning an error message that the page has not yet finished loading if no DCR name has been set. Probably just as clunky from the users' perspectives.

Again, it seems like the key either way is speeding up the IPL Smiley Happy

percentile.rptdesign

ISCBorisB

Any motivating ideas?

Quick and (somewhat) dirty workaround that I've used before to achieve a synchronous TS callout without Ajax was a CGI.
In IE and FF3.x you can use window.showModalDialog() instead of the portable (and asynchronous) window.open() Method.

In general though it's not IMO a good idea to freeze Client thread because of the prolonged Server execution, Ajax
or no Ajax. If you have such a case it's IMO better to bite the bullet and work out threads synchronization.