Useful Smarty TIPS

smarty new release

Smarty allows access to PHP objects through the templates. There are two ways to access them. One way is to register objects to the template, then use access them via syntax similar to custom functions. The other way is to assign objects to the templates and access them much like any other assigned variable. The first method has a much nicer template syntax. It is also more secure, as a registered object can be restricted to certain methods or properties. However, a registered object cannot be looped over or assigned in arrays of objects, etc. The method you choose will be determined by your needs, but use the first method whenever possible to keep template syntax to a minimum.
If security is enabled, no private methods or functions can be accessed (begininning with "_"). If a method and property of the same name exist, the method will be used.
You can restrict the methods and properties that can be accessed by listing them in an array as the third registration parameter.
By default, parameters passed to objects through the templates are passed the same way custom functions get them. An associative array is passed as the first parameter, and the smarty object as the second. If you want the parameters passed one at a time for each argument like traditional object parameter passing, set the fourth registration parameter to false.

Ex, using a registered or assigned object
register_object("foobar",$myobj);
// if we want to restrict access to certain methods or properties, list them
$smarty->register_object("foobar",$myobj,array('meth1','meth2','prop1'));
// if you want to use the traditional object parameter format, pass a boolean of false
$smarty->register_object("foobar",$myobj,null,false);

// We can also assign objects. Assign by ref when possible.
$smarty->assign_by_ref("myobj", $myobj);

$smarty->display("index.tpl");
?>

TEMPLATE:

{* access our registered object *}
{foobar->meth1 p1="foo" p2=$bar}

{* you can also assign the output *}
{foobar->meth1 p1="foo" p2=$bar assign="output"}
the output was {$output)

{* access our assigned object *}
{$myobj->meth1("foo",$bar)}


Smarty Cheat Sheet Version 2.0

Download PDF version (285 KB)
Download GIF Version (304 KB)

Useful Smarty TIPS
Default Variable Handling
f a variable is used frequently throughout your templates, applying the default modifier every time it is mentioned can get a bit ugly. You can remedy this by assigning the variable its default value with the assign function
{* do this somewhere at the top of your template *}
{assign var="title" value=$title|default:"no title"}

{* if $title was empty, it now contains the value "no title" when you print it *}
{$title}


Blank Variable Handling

There may be times when you want to print a default value for an empty variable instead of printing nothing, such as printing " " so that table backgrounds work properly. Many would use an {if} statement to handle this, but there is a shorthand way with Smarty, using the default variable modifier.
{* the long way *}

{if $title eq ""}

{else}
{$title}
{/if}


{* the short way *}

{$title|default:" "}


Dates in smarty

As a rule of thumb, always pass dates to Smarty as timestamps. This allows template designers to use date_format for full control over date formatting, and also makes it easy to compare dates if necessary.
NOTE: As of Smarty 1.4.0, you can pass dates to Smarty as unix timestamps, mysql timestamps, or any date parsable by strtotime().
{$startDate|date_format}

OUTPUT:

Jan 4, 2001


{$startDate|date_format:"%Y/%m/%d"}

OUTPUT:

2001/01/04


{if $date1 < $date2} ... {/if} When using {html_select_date} in a template, The programmer will most likely want to convert the output from the form back into timestamp format. Here is a function to help you with that. // this assumes your form elements are named // startDate_Day, startDate_Month, startDate_Year $startDate = makeTimeStamp($startDate_Year,$startDate_Month,$startDate_Day); function makeTimeStamp($year="",$month="",$day="") { if(empty($year)) $year = strftime("%Y"); if(empty($month)) $month = strftime("%m"); if(empty($day)) $day = strftime("%d"); return mktime(0,0,0,$month,$day,$year); } Componentized Templates

Traditionally, programming templates into your applications goes as follows: First, you accumulate your variables within your PHP application, (maybe with database queries.) Then, you instantiate your Smarty object, assign the variables and display the template. So lets say for example we have a stock ticker on our template. We would collect the stock data in our application, then assign these variables in the template and display it. Now wouldn't it be nice if you could add this stock ticker to any application by merely including the template, and not worry about fetching the data up front?
You can embed PHP into your templates with the {php}{/php} tags. With this, you can setup self contained templates with their own data structures for assigning their own variables. With the logic embedded like this, you can keep the template & logic together. This way no matter where the template source is coming from, it is always together as one component.
{* Smarty *}

{php}

// setup our function for fetching stock data
function fetch_ticker($symbol,&$ticker_name,&$ticker_price) {
// put logic here that fetches $ticker_name
// and $ticker_price from some resource
}

// call the function
fetch_ticker("YHOO",$ticker_name,$ticker_price);

// assign template variables
$this->assign("ticker_name",$ticker_name);
$this->assign("ticker_price",$ticker_price);

{/php}

Stock Name: {$ticker_name} Stock Price: {$ticker_price}