Tips & Tricks 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. Printing   when a variable is empty Default Variable Handling If 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. Assigning a template variable its default value Passing variable title to header template When the majority of your templates use the same headers and footers, it is common to split those out into their own templates and include them. But what if the header needs to have a different title, depending on what page you are coming from? You can pass the title to the header when it is included. Passing the title variable to the header template {$title|default:"BC News"} footer.tpl ---------- ]]> When the main page is drawn, the title of "Main Page" is passed to the header.tpl, and will subsequently be used as the title. When the archives page is drawn, the title will be "Archives". Notice in the archive example, we are using a variable from the archives_page.conf file instead of a hard coded variable. Also notice that "BC News" is printed if the $title variable is not set, using the default variable modifier. Dates 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. As of Smarty 1.4.0, you can pass dates to Smarty as unix timestamps, mysql timestamps, or any date parsable by strtotime(). using date_format This will output: This will output: 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. converting form date elements back to a timestamp ]]> WAP/WML WAP/WML templates require a php Content-Type header to be passed along with the template. The easist way to do this would be to write a custom function that prints the header. If you are using caching, that won't work so we'll do it using the insert tag (remember insert tags are not cached!) Be sure that there is nothing output to the browser before the template, or else the header may fail. using insert to write a WML Content-Type header ]]> your Smarty template must begin with the insert tag :

Welcome to WAP with Smarty! Press OK to continue...

Pretty easy isn't it?

]]> 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 do this by writing a custom plugin for fetching the content and assigning it to a template variable. componentized template assign($params['assign'], $ticker_info); } ?> ]]> Obfuscating E-mail Addresses Do you ever wonder how your E-mail address gets on so many spam mailing lists? One way spammers collect E-mail addresses is from web pages. To help combat this problem, you can make your E-mail address show up in scrambled javascript in the HTML source, yet it it will look and work correctly in the browser. This is done with the mailto plugin. Example of Obfuscating an E-mail Address Technical Note This method isn't 100% foolproof. A spammer could conceivably program his e-mail collector to decode these values, but not likely.