APEX

Hi everyone,

I ran into an interesting behavior while working with a JET Chart region refresh in Oracle APEX.

My chart region title is defined using substitution strings:

    Trend &P10_COUNTRY. / &P10_INDICATOR. 

Both P10_COUNTRY and P10_INDICATOR are Select Lists.

I added a Dynamic Action:

Event: Change → Item: P10_COUNTRY → True Action: Refresh → Region: TREND_CHART

The behavior is the following:

• The chart data refreshes correctly
• But the region title does not update

So the chart shows the new dataset, but the title still displays the previous values of the page items.

I initially tried to keep the solution fully low-code, including computing the title in another page item and using substitution strings, but the region title still did not update after the AJAX refresh.

As a workaround I added a small JavaScript function that updates the region title after the change event:

function setTrendTxt(){ 
try{
  var c = $("#P10_COUNTRY option:selected").text();
  var i = $("#P10_INDICATOR option:selected").text(); 
  var val = "Trend: " + c + " / " + i;
  $("#trend_chart .t-Region-title").text(val);
}
catch(e){console.log('TrendTxt',e);}
}

This function is executed after the item change, and the title then updates correctly.

My question is mainly about the underlying behavior:

• Is this expected behavior because region titles are rendered only during the initial page render?
• Does the JET chart refresh update only the chart component but not the region header template?
• Or is there a recommended APEX-native approach for dynamic chart titles without using JavaScript?

Curious to know if others have run into a similar situation when refreshing chart regions.

Thanks!