.xml - serialization format


A .xml file contains the serialization of an object data structure generated with the XMLSerializer:

The top level elements represent the groups in which the object are organised. The object names are unique within these groups.

<group1>
  <object1 val="value of object 1"/>
  <object2 val="value of object 2"/>
</group1>

<group2>
  <object1 val="value of object 1"/>
</group2>

An object can be of following type:

  • Basic types: char, char*, std::string, bool, usigned int, int, float, double
  • STL containers: std::array, std::vector, std::pair
  • Eigen types: Eigen::Matrix, Eigen::SparseMatrix
  • User defined types: XMLSerializable*.

There can also be a hierarchical structure like vector<int>, this will result in the following serialization:

<group>
  <vector size="3">
    <value0 val="1"/>
    <value1 val="2"/>
    <value2 val="3"/>
  </vector>
</group>

An example of a serialization of an instance of the class Test

class Test{
  int var1;
  vector&ltfloat> vec1;  
};

is shown here:

<group>
  <Test>
    <var1 val="0">
    <vec1 size="2">
      <value0 val="1"/>
      <value1 val="2"/>
    </vector>
  </Test>
</group>

In the following we show the serialization of Eigen matrices.

Eigen::Matrix<int,4,3>:

<group>
  <matrix row="4" col="3" matrix="
1,2,3,
4,5,6,
7,8,9,
10,11,12/>
</group>

Eigen::SparseMatrix<int> (3x3 identity saved as triplets of the non-zero entries):

<group>
  <matrix row="3" col="3" matrix="
0,0,1,
1,1,1,
2,2,1/>
</group>