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@ -1,4 +1,4 @@ |
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## Addons |
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# Addons |
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Addons are dynamically linked shared objects. They can provide glue to C and |
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C++ libraries. The API (at the moment) is rather complex, involving |
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@ -24,7 +24,7 @@ compiling your module, you don't need to worry about linking to any of these |
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libraries. |
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### Hello world |
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## Hello world |
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To get started let's make a small Addon which is the C++ equivalent of |
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the following Javascript code: |
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@ -129,7 +129,7 @@ In cases where there is more than one `.cc` file, simply add the file name to th |
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obj.source = ['addon.cc', 'myexample.cc'] |
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#### Function arguments |
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### Function arguments |
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The following pattern illustrates how to read arguments from JavaScript |
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function calls and return a result. This is the main and only needed source |
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@ -172,7 +172,7 @@ You can test it with the following JavaScript snippet: |
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console.log( 'This should be eight:', addon.add(3,5) ); |
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#### Callbacks |
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### Callbacks |
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You can pass JavaScript functions to a C++ function and execute them from |
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there. Here's `addon.cc`: |
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}); |
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#### Object factory |
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### Object factory |
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You can create and return new objects from within a C++ function with this |
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`addon.cc` pattern, which returns an object with property `msg` that echoes |
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console.log(obj1.msg+' '+obj2.msg); // 'hello world' |
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#### Function factory |
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### Function factory |
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This pattern illustrates how to create and return a JavaScript function that |
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wraps a C++ function: |
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@ -286,7 +286,7 @@ To test: |
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console.log(fn()); // 'hello world' |
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#### Wrapping C++ objects |
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### Wrapping C++ objects |
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Here we will create a wrapper for a C++ object/class `MyObject` that can be |
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instantiated in JavaScript through the `new` operator. First prepare the main |
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console.log( obj.plusOne() ); // 13 |
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#### Factory of wrapped objects |
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### Factory of wrapped objects |
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This is useful when you want to be able to create native objects without |
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explicitly instantiating them with the `new` operator in JavaScript, e.g. |
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console.log( obj2.plusOne() ); // 23 |
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#### Passing wrapped objects around |
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### Passing wrapped objects around |
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In addition to wrapping and returning C++ objects, you can pass them around |
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by unwrapping them with Node's `node::ObjectWrap::Unwrap` helper function. |
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