Javascript events

[JScannell]

I've been wracking my brain for quite a while so I figured I'd reach out to you guys. Here's what I'm trying to do:

1. I have a button that will perform a database lookup using remote scripting.
2. While it is doing all of this, I want an element that has "Please Wait --- Uploading Data" to become visible, or its value to change from "" to "Please Wait --- Uploading Data" so the user can see it.
3. When the process is finished, I want toe <span> to become invisible.

It seems that no matter what I do, no text changes or no display attributes changes until the very end so there is effectively no change to anything!! I currently have the following:

function Update_PLS_Wait ( strValue )
{
alert ( document.getdata.PLS_Wait.value );
document.getdata.PLS_Wait.value = strValue;
alert ( document.getdata.PLS_Wait.value );
return true;
}

function getApparatusName_via_VLICK ()
{
.
.
.
}

Inside my form:
<tr>
<td align=center colspan=2>
<input type="button" name = "clicker1" class="Submit_Button" value = "Lookup Items" onClick = "Update_PLS_Wait ( 'Please wait --- Uploading data' ); getApparatusName_via_CLICK (); Update_PLS_Wait ( '' );">
</td>
</tr>
<tr><td align=center colspan=2><input type = "TEXT" name = "PLS_Wait" id = "PLS_Wait" size="30" maxlength="30" value="" readonly></td></tr>


The crazy thing is that the alerts inside "Update_PLS_Wait ( strValue )" happen but I am unable to see the textbox change when I close the alert()


This issue is the same regardless of whether I have a text element that I change or a span where I change the display property like ( which I wanted in the first place):

<tr>
<td align=center colspan=2>
<input type="button" name = "clicker1" class="Submit_Button" value = "Lookup Items" onClick = "Update_PLS_Wait ( 'block' ); getApparatusName_via_CLICK (); Update_PLS_Wait ( 'none' );">
</td>
</tr>
<tr><td colspan=2><span id="PLS_Wait" name="PLS_Wait" STYLE="display:none">Please wait --- Uploading data</span></td></tr>

Then the Update_PLS_Wait () function would change to this:

function Update_PLS_Wait ( strDisplay )
{
var obj = document.getElementById ( "PLS_Wait" );
obj.style.display = strDisplay;

return true;
}


Thanks in advance,
Jerry


Jerry Scannell

 

[Daniel K]

Here's a working example of what you're trying to do. Hopefully you can use this more modern take on Javascript which uses `const` keyword, the `querySelector` method, and event listeners:

If the HTML is as such:

<span id="waitMessage">initial text</span>
<br>
<input id="aparatusNameButton" type="button" class="Submit_Button" value="Lookup Items">

Then the Javascript can be thus:

const waitMessageSpan = document.querySelector('#waitMessage');

const aparatusNameButton = document.querySelector('input#aparatusNameButton');
aparatusNameButton.addEventListener('click', getApparatusName);

function getApparatusName() {
	alert(waitMessageSpan.innerText);

	waitMessageSpan.innerText = 'Please wait --- Uploading data';

	alert(waitMessageSpan.innerText);

	// ...

	waitMessageSpan.style.display = 'none';
}

Here is a jsfiddle of the working example:

https://jsfiddle.net/kb2yxfLa/3/