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).
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