Smarty检查是否未定义

i am getting errors if smarty variable is undefined.

Here is the code:

< input type="text" value="{$data.allKeywords} id='keyId' />

I am getting the error: Undefined index: allKeywords.

I know the variable - $data.allKeywords is undefined but should it not ignore it if a variable is undefined?

Is there a way to check if it is undefined in smarty template files only ?

Thanks.

You can wrap it in a Smarty if statement

<input type="text" value="{if $data.allKeywords}{$data.allKeywords}{/if} "id='keyId' />