Show an animated “Please wait” indicator after page submit

My application normally responds to button clicks with sub-second performance, but there were a few operations where users can initiate quite long-running transactions (e.g. up to 15 seconds long in one case where it was hitting an eBus interface thousands of times).

When the user clicks the button, I want the page to show a “Please Wait” message with an animated running indicator (I won’t call it a “progress bar” even though it looks like one, because it doesn’t really show progress, it just rotates forever) until the page request returns.

pleasewait

To do this I added the following to my application, based largely on this helpful article.

1. Add an HTML region on Page 0 (so it gets rendered on every page) at Before Footer, with:

<div id="runningindicator">
Processing, please wait...
<div id="runningindicator-img"></div>
</div>

2. Add the following to the global CSS file for my application:

div#runningindicator {
  display: none;
  background-color: #FFF;
  padding: 30px;
  border: 1px solid;
  border-color: #CCC;
  box-shadow: 2px 2px 2px #AAA;
  border-radius: 4px;
  position: absolute;
  top: 100px;
  left: 50%;
  margin-left: -110px;  /* the half of the width */
}
div#runningindicator-img {
  background-image: url(/i/processing3.gif);
  background-repeat: no-repeat;
  width: 220px;  /* the exact width of the image */
  height: 19px;  /* the exact height of the image */
}

3. Add the following to the global javascript file for my application:

function run_long_request (request, warnmsg) {
  if (!warnmsg || confirm(warnmsg)) {
    // disable all buttons on the page
    var btns = $("a[role='button']");
    $x_disableItem(btns, true);
    $("div#runningindicator").show();
    apex.submit(request);
  }
}

4. Change the button:

Action = Redirect to URL
URL Target =

javascript:run_long_request('APPROVE',
  'Are you sure you wish to approve this transaction?');

When clicked, the button runs my javascript function which first prompts the user to confirm, and if they do, it disables all the buttons on the page, shows the running indicator, and submits the request (which might be the name of the button, for example).

If I omit the second parameter, the function skips the confirm popup and submits straight away.

Known Issue: the animated gif doesn’t seem to animate in IE8. So far I haven’t worked out how to solve this, except to burn IE8 with fire and extreme prejudice. I’ve tried using setTimeout to delay showing the div but it stubbornly stays frozen.

EDIT: thanks to Peter Raganitsch who alerted me to a simpler option, that doesn’t need the region or the CSS, and animates in IE8:

function run_long_request (request, warnmsg) {
  if (!warnmsg || confirm(warnmsg)) {
    apex.submit({request:request,showWait:true});
  }
}

Mind you, building this sort of thing from scratch was a useful exercise to learn the CSS and javascript tricks necessary. And another thing re-learned: there’s almost always a simpler way.


Split CLOB into lines

Simple requirement – I’ve got a CLOB (e.g. after exporting an application from Apex from the command line) that I want to examine, and I’m running my script on my local client so I can’t use UTL_FILE to write it to a file. I just want to spit it out to DBMS_OUTPUT.

Strangely enough I couldn’t find a suitable working example on the web for how to do this, so wrote my own version. This was my first version – it’s verrrrrry slow because it calls DBMS_LOB for each individual line, regardless of how short the lines are. It was taking about a minute to dump a 3MB CLOB.

PROCEDURE dump_clob (clob IN OUT NOCOPY CLOB) IS
  offset NUMBER := 1;
  amount NUMBER;
  len    NUMBER := DBMS_LOB.getLength(clob);
  buf    VARCHAR2(32767);
BEGIN
  WHILE offset < len LOOP
    -- this is slowwwwww...
    amount := LEAST(DBMS_LOB.instr(clob, chr(10), offset)
                    - offset, 32767);
    IF amount > 0 THEN
      -- this is slow...
      DBMS_LOB.read(clob, amount, offset, buf);
      offset := offset + amount + 1;
    ELSE
      buf := NULL;
      offset := offset + 1;
    END IF;
    DBMS_OUTPUT.put_line(buf);
  END LOOP; 
END dump_clob;

This is my final version, which is orders of magnitude faster – about 5 seconds for the same 3MB CLOB:

PROCEDURE dump_str (buf IN VARCHAR2) IS
  arr APEX_APPLICATION_GLOBAL.VC_ARR2;
BEGIN
  arr := APEX_UTIL.string_to_table(buf, CHR(10));
  FOR i IN 1..arr.COUNT LOOP
    IF i &lt; arr.COUNT THEN
      DBMS_OUTPUT.put_line(arr(i));
    ELSE
      DBMS_OUTPUT.put(arr(i));
    END IF;
  END LOOP;
END dump_str;

PROCEDURE dump_clob (clob IN OUT NOCOPY CLOB) IS
  offset NUMBER := 1;
  amount NUMBER := 32767;
  len    NUMBER := DBMS_LOB.getLength(clob);
  buf    VARCHAR2(32767);
BEGIN
  WHILE offset < len LOOP
    DBMS_LOB.read(clob, amount, offset, buf);
    offset := offset + amount;
    dump_str(buf);
  END LOOP;
  DBMS_OUTPUT.new_line;
END dump_clob;

Add a Dynamic Total to a Tabular Report

I have a Tabular Report with an editable Amount item. When the page loads, the total amount should be shown below the report; and if the user updates any amount on any row, the total amount should be updated automatically.

Note: this method does not work if you have a tabular report that might have a very large number of records (as it relies on all records being rendered in the page at one time).

1. Make sure the report always shows all the records. To do this, set the Number of Rows and the Maximum Row Count to a large number (e.g. 1000).

2. Add an item to show the total, e.g. P1_TOTAL_AMOUNT. I use a Number field, and add “disabled=true” to the HTML Form Element Attributes so that the user won’t change it.

3. Examine the generated HTML to see what ID is given to the amount fields in the tabular report. In my case, the amount field is rendered with input items with name “f04” and id “f04_0001”, “f04_0002”, etc.

4. Add the following code to the page’s Function and Global Variable Declaration:

function UpdateTotal () {
  var t = 0;
  $("input[name='f04']").each(function() {
    t += parseFloat($(this).val().replace(/,/g,''))||0;
  });
  $s("P1_TOTAL_AMOUNT",t.formatMoney());
}

This strips out any commas from the amounts before parsing them as Floats and adding them to a running total; it finally formats the total using my formatMoney function and updates the total amount item.

5. Add the following to the page’s Execute when Page Loads:

$("input[name='f04']").change(function(){UpdateTotal();});

To prime the total amount field when the page is loaded, I have a Before Header process that calculates the total based on a simple query on the table.

Now, in my case I want to have two running totals: one for “Cash” lines and another for “Salary” lines. My tabular report renders a radio button on each record which the user can select “Cash” or “Salary”. So instead of just the one total amount field, I have two: P1_TOTAL_CASH and P1_TOTAL_SALARY. The radio buttons have hidden input items with the value, rendered with id “f05_nnnn” (where nnnn is the row number).

My UpdateTotal function therefore looks like this:

function UpdateTotals () {
  var sal = 0, cash = 0, amt, rownum, linetype;
  $("input[name='f04']").each(function() {
    amt = parseFloat($(this).val().replace(/,/g,''))||0;
    // determine if this is a Cash or Salary line
    rownum = $(this).prop("id").split("_")[1];
    linetype = $("input[id='f05_"+rownum+"']").val();
    if (linetype == "SALARY") {
      sal += amt;
    } else if (linetype == "CASH") {
      cash += amt;
    }
  });
  $s("P52_TOTAL_SALARY",sal.formatMoney());
  $s("P52_TOTAL_CASH",cash.formatMoney());
}

And my Execute when Page Loads has an additional call:

$("input[name='f05']").change(function(){UpdateTotals();});

Now, when the user changes the amounts or changes the line type, the totals are updated dynamically.

EDIT: simplified jquery selectors based on Tom’s feedback (see comments) and use the hidden field for the radio buttons instead of querying for “checked”

tabularreportdynamictotal

UPDATE: If the tabular form has an “Add Row” button, the above code won’t work on the newly added rows. In this case, the Execute when Page Load should be this instead:

$(document).on("change", "input[name='f05']", function(){UpdateTotals();});

Show/Hide Multi-row Delete button for a Tabular Report

I have a standard tabular report with checkboxes on each row, and a multi-record delete button called MULTI_ROW_DELETE.

If the user clicks the button before selecting any records (or if there are no records), they get an error message. Instead, I’d rather hide the button and only show it when they have selected one or more records.

showhidemultirowdelete

To do this:

1. Edit the MULTI_ROW_DELETE button to have a Static ID (e.g. “MULTI_ROW_DELETE”).

2. Add this function to the page’s Function and Global Variable Declaration:

function ShowHideMultiRowDelete () {
  if ($("input[id^='f01_']:checked").length==0) {
    $x_Hide("MULTI_ROW_DELETE");
  } else {
    $x_Show("MULTI_ROW_DELETE");
  }
}

This looks to see if there are any checkboxes selected, if none are found it hides the delete button, otherwise it shows it.

3. Add this code to the page’s Execute when Page Loads:

ShowHideMultiRowDelete();
$("input[id^='f01_']").change(function(){ShowHideMultiRowDelete();});
$x_Hide("check-all-rows");

This does the initial check on form load (i.e. it initially hides the button, since none of the checkboxes will be selected yet), and adds a listener to the checkboxes so that if any of them are changed, the function is re-run to show or hide the button as needed.

Unfortunately this doesn’t work with the “all rows” checkbox that was generated by the tabular report, so I’ve added a step to hide that checkbox (“check-all-rows”) until I can find a solution for that.