indirect function calls

[Captain Dondo]

I am building repetitive forms using PHP and templates; the PHP loops
through the data and stuffs it into the templates. Javascript functions
then handle each entry field as required.... I am using elements in my
html that look like this:

<button tabindex=%t% id='a%t%' ptype='button'
imageList="/skip.png,/pause.png,/cw.png,/ccw.png" wrap="true"
valTarget='ha%t%' imageTarget='ia%t%'><img src='/skip.png'
id='ia%t%'></button>

where the ptype indicates which javascript function should handle that
particlular element.

So in this case it's a ptype of button.

My javascript key handler then does this:

function DoKey(step, dir) {
if (!activeElement.getAttribute('ptype'))
numericalField(step, dir);
else switch(activeElement.getAttribute('ptype')) {
case 'numerical':
numericalField(step, dir);
break;
case 'button':
buttonField(step, dir);
break;
case 'time':
timeField(step, dir);
break;
case 'date':
dateField(step, dir);
break;
}
}

I can't help but think that I should be able to do something like this:

(activeElement.getAttribute('ptype')+'Field')(step , dir)

to call the function directly... Is there a construct that works like
that or should I stick with the case construct?

[stannyc]

In a recent message, someone pointed out that all Javascript functions
are passed through the Window object, so you can do this:

function firstFunction(str) {
// do stuff
window[str]();

You should be able to apply this directly to your function.

Stan Scott
New York City

Captain Dondo wrote:

I am building repetitive forms using PHP and templates; the PHP loops
through the data and stuffs it into the templates. Javascript functions
then handle each entry field as required.... I am using elements in my
html that look like this:

<button tabindex=%t% id='a%t%' ptype='button'
imageList="/skip.png,/pause.png,/cw.png,/ccw.png" wrap="true"
valTarget='ha%t%' imageTarget='ia%t%'><img src='/skip.png'
id='ia%t%'></button>

where the ptype indicates which javascript function should handle that
particlular element.

So in this case it's a ptype of button.

My javascript key handler then does this:

function DoKey(step, dir) {
if (!activeElement.getAttribute('ptype'))
numericalField(step, dir);
else switch(activeElement.getAttribute('ptype')) {
case 'numerical':
numericalField(step, dir);
break;
case 'button':
buttonField(step, dir);
break;
case 'time':
timeField(step, dir);
break;
case 'date':
dateField(step, dir);
break;
}
}

I can't help but think that I should be able to do something like this:

(activeElement.getAttribute('ptype')+'Field')(step , dir)

to call the function directly... Is there a construct that works like
that or should I stick with the case construct?

[Richard Cornford]

st*****@gmail.com wrote:

In a recent message, someone pointed out that all Javascript
functions are passed through the Window object, so you can
do this:
If anyone did then they were making false statements. Only functions
declared in the global execution context would normally be properties of
the window object. Other functions may be explicitly assigned to
properties of the window/global object at runtime, though that would be
a generally unwise action to take.

<snip> Captain Dondo wrote:

<snip>

Please do not top-post to comp.lang.javascript.

Richard.

[RobG]

Captain Dondo said on 22/04/2006 4:38 AM AEST:

I am building repetitive forms using PHP and templates; the PHP loops
through the data and stuffs it into the templates. Javascript functions
then handle each entry field as required.... I am using elements in my
html that look like this:

<button tabindex=%t% id='a%t%' ptype='button'
imageList="/skip.png,/pause.png,/cw.png,/ccw.png" wrap="true"
valTarget='ha%t%' imageTarget='ia%t%'><img src='/skip.png'
id='ia%t%'></button>
If you want to show your HTML, then post the HTML that a browser
actually gets, not the PHP (or whatever) code that generates it. We'll
fix your client-side issues, how you generate your markup is deal with
in other news groups.

where the ptype indicates which javascript function should handle that
particlular element.
If you know the ptype when generating the page, then you should be able
to insert the correct function when that is done on the server, hence
you have a PHP (or whatever) issue, not a javascript issue.

The value of an HTML element's on<event> attribute is text that is
interpreted as script, so insert the name of the function directly.

So in this case it's a ptype of button.

My javascript key handler then does this:

function DoKey(step, dir) {
if (!activeElement.getAttribute('ptype'))
Where is 'activeElement' defined? Usually the element passes a
reference to itself using 'this':

<button onclick="DoKey(this);" ...>
Then assign it to a variable in the function:

function DoKey(el, step, dir) {
if ( !el.getAttribute('ptype') )
//...

numericalField(step, dir);
else switch(activeElement.getAttribute('ptype')) {
case 'numerical':
numericalField(step, dir);
You could ditch ptype and set the function to call directly:

<button onclick="buttonField(this, step, dir);" ...>
Where step and dir have some value you haven't shown.

[...]
I can't help but think that I should be able to do something like this:

(activeElement.getAttribute('ptype')+'Field')(step , dir)

to call the function directly... Is there a construct that works like
that or should I stick with the case construct?

Use the case (or if or whatever) statement on your server and set the
event handler to the appropriate value in the HTML source.
--
Rob
Group FAQ: <URL:http://www.jibbering.com/FAQ>

[Thomas 'PointedEars' Lahn]

st*****@gmail.com wrote:

In a recent message, someone pointed out that all Javascript functions
are passed through the Window object, so you can do this:

It was wrong then (and I commented on it), and it is still wrong now.

Please learn to quote.
PointedEars
--
Bill Gates isn't the devil -- Satan made sure hell
_worked_ before he opened it to the damned ...