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c++templatesswitch-statementchain-of-responsibility

Replace giant switch statement with what?

I have a code that parses some template files and when it finds a placeholder, it replaces it with a value. Something like:

<html>
<head>
    <title>%title%</title>
</head>
<body bgcolor="%color%">
...etc.

In code, the parser finds those, calls this function:

string getContent(const string& name)
{
    if (name == "title")
        return page->getTitle();
    else if (name == "color")
        return getBodyColor();
    ...etc.
}

and then replaces the original placeholder with returned value.

In real case, it is not a dummy web page, and there are many (50+) different placeholders that can occur.

My code is C++, but I guess this problem exists with any language. It's more about algorithms and OO design I guess. Only important thing is that this must be compiled, even if I wanted I couldn't have any dynamic/eval'd code.

I though about implementing Chain of Responsibility pattern, but it doesn't seem it would improve the situation much.

UPDATE: and I'm also concerned about this comment in another thread. Should I care about it?

Solution

  • Use a dictionary that maps tag names to a tag handler.