How to Call A Specific Line from a Javascript File?

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How to Call A Specific Line from a Javascript File?

1 line out of 100 per post

adder

9:56 am on Oct 17, 2011 (gmt 0)

Hi,

This is a bit challenging and I cannot find an answer in my JS book.

Let's say I have a file myscript.js that consists of 100 lines, each line corresponding to a particular action:

1. document.write('<p>something</p>');
2. document.write('<p>something else</p>');
3. document.write('<p>something entirely different</p>');
etc...

I'm writing a wordpress post and think: ok, I need to embed line 3 in this post.

Can I use some sort of a placeholder to call the line 3? Something like this:


<script language="javascript" src="myscript.js#3">
</script>

Of course, I understand that this example wouldn't work, I'm just trying to illustrate what I'm trying to achieve.

Or maybe I can assign each action to a variable and then call that unique variable with my embed file?

penders

10:46 am on Oct 17, 2011 (gmt 0)

You'll need to use PHP to extract the relevant line from the file. You'll then need to wrap this in <script> tags before writing it out to the page. You won't find a JavaScript only solution to this.

rocknbil

5:56 pm on Oct 18, 2011 (gmt 0)

Something like this? Remember that arrays start at zero, the first member is phrases[0].


<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 
<html lang="en"> 
<head> 
 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> 
 <title>Untitled</title> 
<script type="text/javascript"> 
var phrases = [ 
'<p>something</p>', 
'<p>something else</p>', 
'<p>something entirely different</p>' 
]; 
</script> 
</head> 
<body> 
<p> bla blah blah<strong> 
<script type="text/javascript">document.write(phrases[1]);</script> 
</strong>more blah blah blah. 
</body> 
</html>

if you need to execute them, one of the extremely rare cases where eval would help:


<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 
<html lang="en"> 
<head> 
 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> 
 <title>Untitled</title> 
<script type="text/javascript"> 
var phrases = [ 
"document.write('<p>something</p>')", 
"document.write('<p>something else</p>')", 
"document.write('<p>something entirely different</p>')" 
]; 
</script> 
</head> 
<body> 
<p> bla blah blah<strong> 
<script type="text/javascript">eval(phrases[1]);</script> 
</strong>more blah blah blah. 
</body> 
</html>

Kind of a workaround, but not specifically line by line. I suppose you could write up a PHP/Perl/ASP script that slurps up your .js and outputs the entire thing as an array like the example, then call that like

my-php.php?arraynum=1

adder

8:40 am on Oct 19, 2011 (gmt 0)

Oh, that's interesting. Array might help.

The thing is that in wordpress posts (for some strange reason) I can only add javascript this way:

<script language="javascript" src="myscript.js">
</script>

If I add some operations, they just get stripped when I hit "Post". To solve this I would have to edit the core which I'm reluctant to do because I'd have to do it again each time WP issues an update.

I think you're both right - I'll end up doing something in PHP. I'd probably need a script that creates and writes those javascript files automatically so that I can simply insert a unique .JS file with each post:

<script language="javascript" src="wp-content/myjs/myscript-id-12345.js">
</script>

Skier88

7:01 pm on Oct 19, 2011 (gmt 0)

If you can't use an array then php is probably the best solution, but, in case you were still wondering, a javascript solution is simple as well. Example: include "<script type='text/javascript' src='thisscript.js?line=3'></script>" in any file to execute only the specified line of myscript.js.

var line=/\?(?:.*&)*line=(\d)+/.exec(document.location),
  req=window.XMLHttpRequest?
    new XMLHttpRequest():
    new ActiveXObject('Microsoft.XMLHTTP');
line=+line[1];
req.onreadystatechange=function() {
  if(this.readyState==4) {
    this.status==200?
      eval(this.responseText.split(/\r?\n/)[line]):
      alert('error');
  }
};
req.open('GET','myscript.js',true);
req.send();

Disadvantages: client makes an extra request (=slower), can't load myscript.js from another domain. Advantages: reduces server load.