Getting and setting Apex page item values using $v(), $s(), $v2()

January 11, 2013 at 2:06 pm | Posted in Oracle Application Express (Apex), Oracle Developement | 4 Comments
Tags: apex, application express, javascript, oracle

The Apex JavaScript API has some very convenient functions to access the values of page items.

For example, if you wante to access the contents of a text field with JavaScript, would would need to reference it something like this:

$x("P2_TEXT_FIELD").value;

If the item you want to reference is a display only item, then the syntax changes:

x = $("#P2_DISPLAY_ONLY").text();

If you need to set the values of these items, the you need to use the varying syntax as well:

$x("P2_TEXT_FIELD").value = "Hello World!";

or

$("#P2_DISPLAY_ONLY").text("Hello World!");

Dealing with these various syntax constructs can be confusing. Fortunately the Apex JavaScript API makes this process much easier. To get page item values simply use $v(“<item_name>”):

x = $v("P2_TEXT_FIELD");
y = $v("P2_DISPLAY_ONLY");

To set the item values use:

$s("P2_TEXT_FIELD","Hello World!");
$s("P2_DISPLAY_ONLY","Hello World!");

See an example on my demo page.

The $v2() is handy if you need to access multiple items in an array. For example multiple selections from check boxes or from a shuttle control can be fetched as an array and handled that way in JavaScript:

myArr = $v2("P2_SHUTTLE_CONTROL");
for (idx=0; idx<myArr.length; idx++) {
  //do something with myArr[idx];
}

An example of this functionality can be seen on my demo page, where I also compare $v() and $v2() when used in an array.

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