[PROTON-1288] c++ provide access to message maps as proton::value

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: proton-0.14.0, proton-0.15.0
• Fix Version/s: proton-c-0.18.0
• Component/s: cpp-binding
• Assignee: Alan Conway
• Reporter: Alan Conway
• Created: 24/Aug/16 15:52
• Updated: 24/Oct/17 08:44
• Resolved: 24/May/17 19:44

Description

We need to provide access to the message property maps as a proton::value.

Given

    std::map<string, scalar> my_map;
    proton::message m;

Here are some options:

1. Add new message accessor: proton::value& properties_value()
proton::get(m.properties_value(), my_map)

2. Add value() accessor to cached_map
proton::get(m.properties().value(), my_map)

3. Make cached_map : public proton::value()
proton::get(m.properties(), my_map)

3 is neatest, 1 provides a clearer separation between the case where you want a convenient cached map vs. you want to decode to your own C++ map, work on it, and possibly re-encode it later. I lean towards 3. but open to persuasion.

Issue Links

• is duplicated by: PROTON-1284 C++ binding: No method to allow access to underlying message properties map