This is another one of those utilities that my work requires… well actually it doesn’t I just do this for convenience…
used when concatenating strings with values… I’m going to use a url as an example.
Say we have a variable for our url, and the text to display…
ActionScript Code:
[FONT=Courier New][LEFT][COLOR=#000000]**var**[/COLOR] [COLOR=#0000FF]url[/COLOR] = [COLOR=#FF0000]"http://www.kirupa.com"[/COLOR];
[COLOR=#000000]var[/COLOR] label = [COLOR=#FF0000]“kirupa’s Great Website”[/COLOR];
[/LEFT]
[/FONT]
the way you’d bulid a link out of this would look something like…
ActionScript Code:
[FONT=Courier New][LEFT][COLOR=#000000]**var**[/COLOR] linkHtml = [COLOR=#ff0000]"<a href='"[/COLOR] + [COLOR=#0000ff]url[/COLOR] + [COLOR=#ff0000]"'>"[/COLOR] + label + [COLOR=#ff0000]"</a>"[/COLOR];
[/LEFT]
[/FONT]
Now this will work fine, but it’s ugly, and can get to be not fun when working with complicated insertions. Luckily as a C# developer I have the luxury of using something called the String.Format() method which allows us to do this…
build our string…
ActionScript Code:
[FONT=Courier New][LEFT][COLOR=#000000]**var**[/COLOR] [COLOR=#0000ff]url[/COLOR] = [COLOR=#ff0000]"http://www.kirupa.com";
var label = “[/COLOR]Kirupa[COLOR=#ff0000]'s Great Website”;
var linkHtml = “<a href=’[/COLOR][COLOR=#000000]{[/COLOR][COLOR=#000080]0[/COLOR][COLOR=#000000]}[/COLOR][COLOR=#ff0000]’>{1}</a>”;
var final_html = stringFormatter(linkHtml, url, label); [/COLOR]
[/LEFT]
[/FONT]
The syntax is String.Format(string, args);
you’ll notice in our string, we have {0} and {1}… these are our replacement markers… and our args are the arguments to replace… in our example…
url is argument0 and label is argument1, so anywhere we see {0} it will be replaced with argument0 (url) and anywhere we see {1} it will be replaced with argument1 (label)… we can do this with as many arguments as we’d like.
I hope that some of this came in clear, here’s the class
// this is a class we will use to transform strings
// it will grow as we see fit.
// for the most part just a method library geared towards
// strings specifically
/*
*
*@author Michael Avila
*@version 1.3
*@description This is a class for handling strings.
*/
class StringUtility
{
/* Replaces all occurances of one series of characters with another series of characters
*
* @param The string you are invoking the replace on.
* ...
* @param The series of characters which you plan on replacing
* ...
* @param The series of characters you are replacing with.
*
* @return The string with our values replaced
*
* @usage <pre>StringUtility.replace("Hello World", "World", "Michael");</pre>
*/
public static function replace(original : String, string1 : String, string2 : String) : String
{
var return_string : String = "";
var start_position : Number = 0;
var end_position : Number = 0;
while (true)
{
start_position = original.indexOf(string1, end_position);
if (start_position == -1) break;
return_string += original.substring(end_position, start_position);
return_string += string2;
end_position = start_position + string1.length;
}
return_string += original.substring(end_position, original.length);
return return_string;
}
/* Returns whether or not your series of characters is contained within this string
* @param The string you are going to be looking in
* ...
* @param The strings of characters that you will be looking for.
*
* @return Returns true if all the specified arguments are contained in the string
* and false if not.
*
* @usage <pre>StringUtility.contains("this is the search string", "this", "search");</pre>
*/
// checks whether or not a string contains a specific series of characters
public static function contains(the_string : String, args : String) : Boolean
{
// how many different strings are we checking for...
var strings : Number = arguments.length-1;
// loop through how many we are checking for, and
for (var i:Number=0; i<strings; i++)
{
if (the_string.indexOf(arguments[i+1]) == -1)
{
// if the string does not contain what we asked for.
return false;
}
}
// if we get this far, then the string did contain everything we asked for...
return true;
}
/* Inserts values into a string.
* @param The string you are going to be inserting values into
* ...
* @param The values that you will be adding into the string
*
* @return Returns the string with all of your values inserted
*
* @usage <pre>StringUtility.insertion("Hello: {0}, this is visit number {1}.", "Michael", "20");</pre>
*
*/
public static function insertion (original : String, args : String ) : String
{
// some constants.. what are markers tags are...
var MARKER_OPEN : String = "{";
var MARKER_CLOSE : String = "}";
// The string with all the values set...
var new_string : String = "";
// represents our current search position of the character {
var position_1 : Number = null;
// represents our current search position of the character }
var position_2 : Number = null;
// the number that represents the marker (argument) value that we are currently on
var argument : Number = 0;
// the string we are replacing our argument with
var argumentValue : String = "";
while (true)
{
// the position we are searching from...
var search_from : Number;
// if the position has not been set, start from the beginning
if (position_1 == null)
{
search_from = 0;
} else
{
search_from = position_1 + 1;
}
// set position to the next index of the next instance of our MARKER_OPEN
position_1 = original.indexOf (MARKER_OPEN, search_from);
// if there are no more instances of MARKER_OPEN in this string, then break from the loop
if (position_1 == - 1) break;
// where we will begin the slicing of our string at... start at 0
var start : Number = 0;
// where we will end the slicing of our string at... end at position_1
var end : Number = position_1;
// if position_2 has been set, then start is always the character index AFTER position_2
if (position_2 != null)
{
start = position_2 + 1;
}
// add to new_string the contents between this and the last marker
// if this is the first marker then it just adds from the beginning of the string
new_string += original.substring (start, end);
// set position_2 to the index of MARKER_CLOSE after our current MARKER_OPEN
position_2 = original.indexOf (MARKER_CLOSE, position_1);
// parse the argument as an integer.. requires string manipulation to pull the marker
// value out.
argument = parseInt (original.substring (position_1 + 1, position_2));
// pull from the arguments array the value that will replace this marker...
argumentValue = arguments [argument + 1];
// add our argument value, so that our new_string no longer contains a marker, but
// instead the value
new_string += argumentValue;
}
// when we are done, there are no more markers, so just add on the remainder
// of our original string from the last marker on, onto our new_string
new_string += original.substring (original.lastIndexOf (MARKER_CLOSE) + 1, original.length);
// return our string with all the inserted values
return new_string;
}
}
******* UPDATED
Now has contains and replace methods… and a documentation…
www.nowtheworld.com/ASDocs/StringUtility
Take Care.
_michael
