[Cppcms-users] Whats the role or url_mapper in cppcms

[Neel B. <nee...@gm...>]

In the example on
http://cppcms.com/wikipp/en/page/cppcms_1x_tut_url_mapping  it
keeps a map of regex url pattern and its corresponding action with
`dispatcher().assign()`. But  what is the job of `mapper().assign()` ? even
if I comment that out it works.

In documentation it says

> we create a name for this part called "number" and we provide a URL
> formatting pattern /number/{1} - the opposite of regular expression
> where {1} is a placeholder for the first parameter for formatting the
> appropriate URL.

But why create *a name for the part* and why its necessary ?

    hello(cppcms::service &srv): cppcms::application(srv){
        dispatcher().assign("/number/(\\d+)",&hello::number,this,1);
        mapper().assign("number","/number/{1}");

        dispatcher().assign("/smile",&hello::smile,this);
        mapper().assign("smile","/smile");

        dispatcher().assign("",&hello::welcome,this);
        mapper().assign("");

        mapper().root("/hello");
    }


Thanks
- Neel