m i l e s LASSO TIPS for NEWBIES: 3.1 THREE LIL TOYS
Oct 10, 2005; 14:28
m i l e s
LASSO TIPS for NEWBIES: 3.1 THREE LIL TOYS
- Hi and Welcome to -
++++++++++++++++++++++++++++++++ LASSO TIPS FOR NEWBIES: 3.1 ++++++++++++++++++++++++++++++++
I'm your host, M i l e s.
First and foremost, a good place for you to start with Lasso is the following 5 things:
The FIRST LASSO TIPS FOR FILEMAKER -> http://www.listsearch.com/FileMakerProTalk.lasso?id=151351 The LAST LASSO TIPS FOR FILEMAKER -> http://www.listsearch.com/FileMakerProTalk.lasso?id=153721 10 LASSO RESOURCES -> http://www.listsearch.com/lassotalk.lasso?id=143018 THE LASSO RESOURCES ADDENDUM -> http://www.listsearch.com/lassotalk.lasso?id=143417 OMNIPILOT RESOURCE LIST -> http://www.omnipilot.com/Resources+for+Beginners.2225.lasso http://www.omnipilot.com/Tip+of+the+Week.1768.lasso http://www.omnipilot.com/Hosting+Providers.1744.lasso http://www.omnipilot.com/Frequently+Asked+Questions.1791.lasso
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ THIS PORTION OF LASSO TIPS Æ’or NEWBIES IS SPONSORED BY:
P O I N T I N S P A C E H O S T I N G http://www.pointinspace.com/
Professional Lasso / MySQL / FileMaker Hosting Mention this ad on sign-up and receive 5% off your account! +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Secondly, Chickens DO come home to roost. Eventually. As I had indicated in my last LTÆ’N/F/ & now MySQL, there will be a LASSO SUMMIT!!! Yes that's right kiddies, its time to break out the champagne and get your groove on with others of our kind, your Lasso Brethren. Praise be to all things Lasso. The dates Feb 17 - 19th 2006, in Ft. Lauderdale, FL. By now you've seen the 'official' announcement, so this is nothing new, but those of who haven't, go here: http://www.lassosummit.com/ Grok to your hearts content. Word is that I, your magicmilesness, will be hosting a roundtable or two.
Thirdly, I will conducting newbie training for Lasso, on the 2 days before Lasso Summit. If you've enjoyed Lasso Tips for Newbies, then the time is at hand to get it from the original Lasso Evangelist himself...ME. Dates: Feb 16 - 17, two FULL days of Lasso Training for the Neophyte (the unwashed masses). More details and the official announcement later on this week, but let's keep this just between you and I for the moment (and 10,000 of our closest friends). Seating will be limited.
++++++++++++++++++++++++++++++++ TODAYS TIP: T h r e e L i l T o y s ++++++++++++++++++++++++++++++++
Today's tip is actually 3 tiny tips that have been buggin me for months that I frequently see others not taking advantage of, that you can USE today. No if's, and's, or but's about it. So without further adieu....on with the tips.
PART ONE: ITERATION is the KEY!
From time to time you will run across the need to pull values out of a variable and reorder them as you see fit. OR just get the values out and use them as you see fit. There are several ways to do this with Lasso, however none more powerful than the ITERATE tag. Some of you have seen this tag before and probably thought to yourselves that it looks just a tad scary, and you know what, you'd be right. It is. Its just downright intimidating! Coming from a newbie standpoint, it is. However as with all things, it just needs lil light shed on it to give it a lil clarity, so that perhaps you won't shy away from the thing the next time you run across the need to use it.
In its basic form an [iterate] tag is very similar to a [loop] or [while] statement. They all do the same things, sort of. Except that a LOOP or WHILE statement doesn't actually allow you to use itself as the comparitor statement, or in simpler parlance, to compare itself against itself! A loop will continue running a series of operations to a certain number; a WHILE will continue doing the same thing while a certain condition is true; but an ITERATE statement, an iterate statement will go several steps further than either and allow you to stop and examine the values that you feed it and change it in process! And that my Lasso Brethren is where the rubber hits the road and why this lil toy is SOOOO amazingly powerful.
Im going to do something that may make you a bit fearful, but I'll 'splain as I go along...
// initializing an array [var: 'a_mytest' = (array)]
//adding values to the array [$a_mytest = (array: 'apples', 'oranges', 'pears', 'grapes')]
//for each value in the array put a value into the variable 'fruits' [iterate: $a_mytest, (var: 'fruits')]
// display each value of $fruits on its own line and add a line break. I love: [$fruits]<BR>
// close iteration when completed [/iterate]
So in essence all I did was populate a data storage unit (an array, which is like a series of cubby holes), and tell the iterate to take each value in the array, and display it as its own variable! While this example doesn't show the true power of an iterate statement it does show the promise of it...so lets take a real world example.
Suppose you have a series of filenames in a field and each filename is separated by a comma, and you want to take those filenames and create links from them. How would you do this ? You could use a LOOP statement to go through the field and then find the values, but then you'd have to build a series of conditional statements to actually build links to the actual files. Not really helpful. Enter the ITERATE statement!
[var: 'a_myfiles' = (array)] [var: 'a_myfiles' = ((field: 'user_files') -> (Split: ','))] // converting the field contents to an array. [iterate: $a_myfiles, (var: 'v_filename')] <a href="[$v_filename]">[$v_filename]</a><BR> [/iterate]
The only thing that is different here from the last code snippett is the 2nd line.
Now let's really show the power of the iterate statement...
[var: 'a_myfiles' = (array)] [var: 'a_myfiles' = ((field: 'user_files') -> (Split: ','))] // converting the field contents to an array. [iterate: $a_myfiles, (var: 'v_filename')] [if: ($v_filename) !>> 'no']<a href="[$v_filename]"> [$v_filename]</a><BR>[/if] [/iterate]
Same as before...only NOW Im making it conditional. And the conditional is that if the filename DOES NOT contain the characters 'no', then display the link. This conditional checking, and the ability to check against itself, is what separates an iterate from a LOOP or WHILE. Because the conditional check doesn't exist, the variable doesn't exist, the only thing that exists is the data. You can't do this effectively with a LOOP or WHILE statement (operative word in the sentence: effectively).
PART TWO: PIMPIN' THE '&' AND '+' OPERATORS
This is sooooo simple it should be outlawed. I actually had to have this explained to me like I was a 5 yr old. Hopefully you won't need that here.
a.) THE '+' sign. What is it ? Anywhere where Lasso sees a '+' operator it takes whatever is on the left side and on the right side and mushes them together. If its a literal (text), it will pull them together. If its a numeric, it will add the two values together. If its two variables, it will pull them together. It wont, however, add two arrays together, for that you need to use: array -> merge, however it will stick both arrays right next to one another. Which probably won't help you much, and will more than likely confuse the hell out of you until you discover array->merge! I digress. So let's look at this...
[1 + 1] run that and see what you get. (hint this is really easy)
now try: [1 + ' plus one'] and see what you get.
and now ['one ' + 'plus' + ' one' + ' equals: ' + (1+1)]
the '+' is really that powerful. It can completely replace [string_concatenate] and its completely safe for literals and numerics. The really cool part about that last line, is that Lasso pulled together string literals AND did a math calculation at the same time! Is this a cool language or what ? Ok, so its silly but you get the point. Its just another way to pull your data together.
b.) The '&' sign. What is it ? Think of it this way, the simple way to describe what the operator does would be that it returns an object after something has modified it. Take the following example to read header values:
The example takes the passed header values (the right side values of the name value pairs) and sets them all into a single variable, sorts them (because this an array), then takes each pair of the array and adds a '<BR>' where the was none before and then converts text into upper case.
Ok now lets do the same thing in one line using the "&" sign:
The major difference between these two methods ? Note that the first way is 5 separate operations, AND requires you to declare a variable at every step of the way. Using the & sign ? Requires no variable declaration whatsoever, and is ONE operation. Can you say SPEEEEEEEEED!
Still don't get it ? Think of an '&' sign as a super text and variable replacement tool on steriods! That and a bag of chips, and that my friends is just the tip of the iceberg.
PART THREE: Variable Check!
Ever want to see that your variable has been created ? Think there's no way to do that ? This may sound silly but there are times you actually need to check to see if a variable has been created. In order for you to check to see if a variable has been created is to do the following: [var_defined: 'e1']. This statement will check if the variable e1 exists in the lasso variable map. If its NOT there, it will return FALSE as a value. If it IS there it will return TRUE. So how is this helpful ?
var: 'v_passedparams' = (array); // setting variable to an array var: 'v_passedparams' = (client_postparams); // passing in array values from client_postparams which is a pair array var: 'v_pp_size' = (integer: $v_passedparams->size); // getting the size of the array $v_passedparams->(remove: $v_pp_size); // removing the last item from the array
iterate: $v_passedparams, var:'loopvalues'; // setting only the values that were passed into the array (var: ($loopvalues->name)=($loopvalues->value)); /iterate;
The script above sets an array for passedparams, then moves all the values for client_postparams into the array, then checks the size of the array and sets the value to an integer, then grabs that value, and removes the very last value from the array. It then sets an iterate statement to grab all the values from the array of parameters into separate variable with values (fully populated). In short this tiny lil script will allow you to grab and set a series of passed values into actual variables and populate those variables with their cognate values. This is what is referred to as Dynamic Variable Creation, which can be somewhat dangerous in certain cases. There are times when you'll want to use a method like this, and at the same time, check to see if the variables that were passed in, actually exist, enter the var_defined statement:
if: (var_defined: 'e1'); ...etc.../if;
The statement above checks to see if e1 was created and exists. It does NOT check to see if e1 contains a value, we assume that e1 will contain a value if its been passed.
THE SHORT AND SWEET: These are tiny lil tips that if used properly can help you get to a different place in your Lasso Development work.
Happy Lassoing ~ Let us ALL double click! Praise be to Lasso.
M i l e s.
Spreadin' The Lasso Gospel! LASSO-MYSQL CONSULTANT & EVANGELIST FOR HIRE -don't know what 'lasso' is ? - http://www.omnipilot.com/ ------------------------------------------------------------ M i l e s email@example.com ToolboxEngine - Custom CMS for everyone (415) 686 - 6164 http://www.lassoconsultant.com/ AIM/Yahoo/MSN: magikmiles ------------------------------------------------------------ Creating custom content management systems for yoga, dance, healing arts, & now real estate starting at just $65.00 a month, incld: domain registration, web hosting, email and webmail, and access to TOOLBOXENGINE! A very robust tool. ------------------------------------------------------------ -- ------------------------------ Lasso Support: http://support.omnipilot.com/ Search the list archives: http://www.listsearch.com/lassostudiotalk.lasso Manage your list subscription: http://www.listsearch.com/lassostudiotalk.lasso?manage
This site manages and broadcasts several email lists pertaining to Lasso Programming and technologies related and used by Lasso developers. Sign up today!