PHP Template condition

<if a == 5 && b < 4>
    one
<else>
    <if a != 5>开发者_Go百科
        two
    <else>
        <if a == 5 || $b == 5>
            three
         </if>
     </if>
</if>

How i can get from it a some variables:

[0] = "a == 5 && b < 4"
[1] = "one"
[2] = "a != 5"
[3] = "two"
[4] = "a == 5 || $b == 5"
[5] = "three"

Or how would you suggest to make conditions in the template?

---

I have nothing against templating systems in general, but why not use plain PHP for this?

<?php if ($a == 5 && ($b < 4)): ?>
    one
<?php elseif ($a != 5): ?>
....

I don't see the benefit of painfully rebuilding the parsing and evaluation logic inside PHP.

If you really need this, I would use Smarty.

---

As soon as you start introducing flow control constructs (if, loop... ) to your template language, you lose the ability to apply a template simply by applying a search-and-replace over your variables. You need to start parsing the template to extract the parts that are dependent on a condition, and re-insert them separately should the need happen.

What you will probably end up doing is apply an initial parsing step that turns:

Template "main" :  FOO <if a> BAR </if> QUX

Into:

Template "main" : FOO {temp-if-a} QUX
Template "temp" : BAR

Then, if a is true, you would apply template temp and store it into variable {temp-if-a} while rendering template main. If a is false, you would provide no value for {temp-if-a}.

The other control flow structures can be similarly implemented with this extract-apply independently-replace sequence, including nested ones (just have your template application algorithm work recursively).