How to better understand parameter binding rules

[ericel]

Is this a true limitation or I am just not understanding the usage?

Drogon's CSP Syntax Limitation

The <%view%> directive seems to be primarily for rendering subtemplates, but it doesn't automatically forward variables from the parent context.

Unlike some templating engines (e.g., Jinja2, Django), Drogon requires explicit parameter passing.

This

<%c++ 
             if (!recommendedUsers.empty()) {
                       for (const auto& user : recommendedUsers) {
            %>
                     <%view user_card_connected  user=user %>  
                            <%c++ 
                                    } 
          } else {
                            %>
         <p>No recommended users found.</p>
                            <%c++ 
                                }
        %> 

The user_card_connected.csp holds something like this <hi><%c++ $$ << user.username; %></hi>

Fails to work with the error

keFiles/wahalao.dir/Unity/unity_6_cxx.cxx:22: /Applications/dev/cplusplus/wahalao/build/generated_views/module_network/user_card_connected.cc:23:36: error: use of undeclared identifier 'user' 23 | user_card_connected_tmp_stream << user.username; | ^ 1 error generated. ninja: build stopped: subcommand failed. ✗ C++ build FAILED.

[an-tao]

Currently you cannot pass parameters in subview tags. But maybe you can add user parameters like this:

<%c++ 
             if (!recommendedUsers.empty()) {
                       for (const auto& user : recommendedUsers) {
                           @@.insert("user",user);
            %>
                     <%view user_card_connected %>  
                            <%c++ 
                                    } 
          } else {
                            %>
         <p>No recommended users found.</p>
                            <%c++ 
                                }
        %> 

[ericel]

Haha. I tried that. But it didn't work.

On Wed, May 28, 2025 at 10:54 AM An Tao @.***> wrote:

an-tao left a comment (drogonframework/drogon#2325) https://github.com/drogonframework/drogon/issues/2325#issuecomment-2914644770

Currently you cannot pass parameters in subview tags. But maybe you can add user parameters like this:

<%c++ if (!recommendedUsers.empty()) { for (const auto& user : recommendedUsers) { @@.insert("user",user); %> <%view user_card_connected %> <%c++ } } else { %>

No recommended users found.

<%c++ } %>

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