What is a trigger function with respect to event driven programming? And especially with regard to vb6.
I have searched microsoft documentation as thoroughly as I can and come up with a blank.
Triggers are common in DB environment (SQL Server, etc). As far as I know, there are no triggers in VB6 per se.
You can apply a trigger on a table to perform a certain task when data in that table changes (a new record inserted, etc).
More info on SQL Server triggers
There is no such thing as a "trigger function" in VB6. I think you have misunderstood the wording a bit.
An Event is the concept of something that happens in the application, like a button click, mouse move, form load, etc.
Each Event may be handled by an Event Handler, which is a function that is executed when a given event occurs on a given object, e.g. Button1_Click for handling the Click event on a button named Button1. Note: This function is called Handler function, not Trigger function.
An Event may be Triggered (more often called Raised), which means that an object indicates to the environment that the event has occurred. In the above example, the button named Button1 Triggers/Raises the Click Event.
Related
According to the XForms specification most events are said to "bubble".
As per the DOM Level 2 Event Specification an event that "bubbles" means that the handlers for this event associated with ancestor elements of the event dispatch target will also receive this event.
For an event to be specified as "bubbles" it means the xf:dispatch action cannot modify the bubble behavior to limit it to the target.
I don't understand what the benefit is of so many xforms events to bubble. For example, xforms-select and xforms-deselect. They apply to xf:item (of xf:select*) and xf:case (of xf:switch, i.e., used in a form with tabs).
Let's say I have an xf:case with an xforms-select handler that will cause a refresh on an expensive rendering widget, just when the tab is actually selected rather than every time the model is updated. Now I also have an xf:select in that same tab. Now whenever the user selects another item in that selection, the xf:case would receive the xforms-select at the bubble phase, doing the costly update operation every time.
This doesn't seem to make sense.
In fact xforms-node-attached has it right: we really want to be specific as to which form element gets the node attached. But apart from that, most events are said to bubble.
I could conform myself better with this issue if I understood the reason for this. Otherwise I am tempted to change my XForms engine to change the definition of xforms-select and xforms-deselect not to bubble.
This is to allow what is known as event delegation:
"Event delegation refers to the process of using event propagation (bubbling) to handle events at a higher level in the DOM than the element on which the event originated. It allows us to attach a single event listener for elements that exist now or in the future." (from an older version of this jQuery doc page)
In general, this is a good thing:
You use less event listeners.
A listener can listen on multiple targets.
You don't need to remove/add listeners as DOM elements are added/removed.
It seems that, in the HTML world, things have moved towards letting everything bubble. For example, the old focus event didn't bubble, and the newer focusin event bubbles.
If you have an event handler which gets activated by events dispatched to multiple targets, in some cases you need the ability to discriminate. This is where event context information is useful. Libraries like jQuery also allow you to associate an event handler filtered by CSS selector, which is neat.
Now in the case of xforms-select specifically, your issue is that you cannot discriminate between this event dispatched to an xf:case vs. an xf:select. This might mean XForms shouldn't have a single event for these two scenarios, or it should have enough event context information to discriminate between the two. I don't think that this is making a case for not letting the event bubble.
I want to create a dynamic action, that will set a value to an item on the page, when the value of another item (autocomplete text field) is set.
So the proccess goes like this:
Click on the autocomplete field
type some letters
choose one of the suggested values
I cannot find an event that will be executed when the selection of one of the suggested values happens. This way, I cannot see how I can read the value of the autocomplete field, once a suggested value is selected.
The change event doesn't fit my needs, it doesn't execute when one suggested value is selected.
I had the same problem, found this link: https://community.oracle.com/thread/2130716?tstart=0 and modified my dynamic action as follows to get the desired behaviour:
Event = Custom
Custom Event = result
From the link:
the problem seems to be the default behavior of the browser. When you
enter some text into the autocomplete and the list is displayed, the
focus is still in the text field. Also if you use the keyboard cursors
to pick an entry the focus will still be in the textfield. That's why
the change event of the textfield doesn't fire. It only fires if you
leave the field.
On the other side if you pick an entry with the mouse, the browser
will remove the focus from the text field for a moment (before the
JavaScript code puts the focus back), because you clicked outside of
the field. But that's enough so that the browser fires the change
event.
I had a look into documentation of the underlaying jQuery Autocomplete
widget
(http://bassistance.de/jquery-plugins/jquery-plugin-autocomplete/) and
there is actually an event called "result" which can be captures if an
entry is selected from the drop down list.
Try "Lose Focus" as event. It will trigger your dynamic action when you leave the autocomplete field, i.e. your curosr is moved to another field.
This probably depends on the APEX version you are using.
In case of 18.2, because the underlying component is based on Oracle JET's "inputSearch" component, you need to use following configure to capture the select change event for text with autocomplete:
event: Custom
custom event: ojupdate
Reference:
https://docs.oracle.com/cd/E87657_01/jet/reference-jet/oj.ojInputSearch.html#event:optionChange
I turned on the browser console, then turned ApEx Developer toolbar debug, and found that, on the contrary, the "Change" event does fire upon user clicking with the mouse on one of the selections. However if the user uses keyboard (type a few letters to narrow the list down, then use down arrow key to arrive at desired value, then press enter) then the Change event does not fire, just as you say.
Moreover: even when you do get the value sent back via mouse-click initiated Change event, the value isn't the autocomplete's complete and valid value, but instead the possibly partial and wrong-case value just as typed by the user. I.e., the the change event's submission of the value precedes the autocomplete's substitution.
The answer that #VincentDeelen gave is the best alternative that I can see, although it doesn't quite give that "instantantenous synchronicity" feel. You could maybe use the "Key Down" event, but be careful with that. You could get a really excessive amount of web and db traffic as each and every keystroke (including corrections) results in another firing of the dynamic action.
Testing environment: ApEx 4.2.3 with Chrome 33 as well as IE 9.
p.s. This might be worth a mention to the ApEx development team as well.
It's not really ideal, but you could use onfocus(). I'm looking for the same thing you are, I think, a custom event that fires when the selection of a suggested value happens. I haven't found it yet though and that is my work-around for now. It will run whatever function you've created for this initially with no value, but once the selection is made it will return focus and run the function again with the right value. Like I said, not ideal but it works.
Jeffrey Kemp is right. You can set it up through a dynamic action using the custom event, result. You can also register it on page load using document.getElementById("{id}").addEventListener("result", {function}); or $("#{id}").result( function( event, data, formatted ) { //something here });.
Oracle apex 19 now added a "component event" when you create a dynamic action called "Update [Text Field with autocomplete]" - this action is fired when you select a value from the list, but not when you leave the field (similar to adding the custom event "ojupdate").
Our team is setting up test scripts for automating interaction testing using QTP, for an ExtJS based application.
Many of our elements/objects are being detected as desired, with the exception of column header sorting triggers.
Our grid panel has remote sorting, however programatically triggering a column header "click" doesn't fire our sorting, although "click"ing manually on the column header does. I've tried mousedown and mouseup, on the column header Div, and it's children -titleEl and -textEl as well.
Any ideas?
Thanks in advance.
The simplest way would be to tell QTP to generate mouse events, this way all the events that are fired when a real human clicks the header will be fired when QTP clicks it.
As seen here
origReplayType = Setting.WebPackage("ReplayType")
Setting.WebPackage("ReplayType") = 2
Browser("B").Page("P").WebElement("column header").Click ' your script line here
Setting.WebPackage("ReplayType") = origReplayType
If this is a common occurrence you can use RegisterUserFunc to define a new DeviceClick function to your test objects.
A slightly more complex way is to debug the application and see which event triggers sorting the column and then use FireEvent with the correct event.
I've read a bunch of articles on how to call dialogs from javascript and integrate them into a ribbon button, but I am running into a problem where I need to do all that AND pass in a string as an input parameter (to a child dialog?).
Is this possible? Would I have to modify the calling url of the dialog?
I've read this one about calling dialogs with the SelectedControlAllItemsId, which is almost what I need.
Ideally I would open the form of the parent entity, click on one of the subgrids in the left hand navigation, then select some of the related/associated entities, click the ribbon button and wait for the dialog or workflow to chew through all of those Ids.
Is it possible to capture these selected items using SelectedControlAllItemsId, then pass that string to a child dialog so it can then call another workflow? Or should I capture that string, store it in the calling record via REST and then let a workflow run on a field-trigger?
The end result is that I must run a custom workflow and manipulate the parent record + the selected related records. I have already written the workflow, but I do not know how to trigger it the way I want.
Perhaps there is something I am overlooking? Is there a way to call a custom bit of code directly from javascript and let it work the rest of the way?
I'm not sure how an interactive dialog should deal with a collection of records. Surely that would require sequential iterations of the dialog, as the user processes each record? As you will see from the SDK (and discussed in your linked thread), it is only possible to run a dialog against a single record.
A workflow is a different matter.
- Custom ribbon button, using SelectedControlAllItemsId
- Supporting JScript handler should iterate SelectedControlAllItemsId
- Each iteration should issue an ExecuteWorkflowRequest using the current item id and based on code such as this (which issues an ExecuteWorkflowRequest from JScript
Remember that the workflow request is asynchronous so you can just send all the requests one after another rather than waiting for the outcome of each request.
My project is using Wicket's AjaxFormValidatingBehavior to auto-save form content to Session on sort of a multi-tab form with a tree menu (there is no save button on individual tabs, though there is a "Save" button that actually submits the form, runs the validations and saves contents to database). I am facing few issues:
Since the behavior is added to all form components' onChange event, there is a server-trip every time user moves from one field to another. I know that a throttle duration can be specified to prevent this, but its not possible to set in my case as my forms are of different lengths/complexity, many components dynamically generated (including the tree menu). But is there a more elegant solution to auto-save form content (that doesn't have a submit button) rather than this annoying solution.
Another issue I am facing is that post onChange event, on Firefox the component loses its focus after the "server trip" ends. While on IE7 it works fine.
For the first question I think you need to add a pipelining facility, on your components' onchange call a javascript function of your which calls your webapp. You can include a feature similar to the one provided with the throttle duration but page-wide (delay each calls and only trigger the last if it is older than x milliseconds for example).
For the second one, I think you have to use the AjaxRequestTarget#focusComponent in your behaviors, or handle this thing in your "wrapper" as described in the first answer.