gICAPI.onFocus()

The gICAPI.onFocus() function is used to detect if the WEBCOMPONENT field lost or acquired focus.

Purpose of gICAPI.onFocus()

The gICAPI.onFocus() function is called when the runtime system gives/grabs the focus to/from the WEBCOMPONENT field.

Note: The gICAPI.onFocus() function is mandatory to implement a gICAPI web component.
Focus gain or loss is defined by the polarity parameter passed to the gICAPI.onFocus() function:
  • When the runtime system gives the focus to the WEBCOMPONENT field, the polarity parameter is true.
  • When the runtime system grabs the focus from the WEBCOMPONENT field, the polarity parameter is false.

When polarity is true and HTML elements of the web component can get the focus, the gICAPI.onFocus() function must set the focus to the expected element inside the web component.

This function can also be used to handle an internal flag, to know if the web component has got the focus. If the web component has the focus, you can call the gICAPI.SetData() function to provide the current value of the WEBCOMPONENT field.

When is gICAPI.onFocus() called?

The gICAPI.onFocus(polarity) function is called with polarity=true in the following cases:
  • If the current dialog selects the WEBCOMPONENT field, as a normal tabbing candidate,
  • If the user code executes an explicit NEXT FIELD instruction (or equivalent dialog instruction) to the web component,
  • If the web component JavaScript code asked to get the focus with gICAPI.SetFocus(), and the program has accepted to give the focus to the WEBCOMPONENT field.
The gICAPI.onFocus(polarity) function is called with polarity=false in the following cases:
  • If the current dialog gives the focus to another field, as a normal tabbing candidate,
  • If the user code executes an explicit NEXT FIELD instruction (or equivalent dialog instruction) to move to another field,
Note: The gICAPI.onFocus() function will not be called with polarity=false, if the web component JavaScript code asked the focus with gICAPI.SetFocus(), and the program refused to give the focus.

Example

The following code example defines the gICAPI.onFocus() function to set an internal flag and give the focus to the textarea:

var has_focus = false;

var onICHostReady = function(version) {

    ...

    gICAPI.onFocus = function(polarity) {
        has_focus = polarity;
        if (has_focus) {
            var field1 = document.getElementById("field1");
            field1.focus();
        }
    };

    ...

};