Layer order and arranging layers
Layer stack is an ordered set of layers. Layer's position in the stack reflects to the topic resolution in Wandora. Layer order in the stack has an effect to the topics and associations in Wandora. General rule is that a topic inherits properties from the top layer consisting the topic property. Top property overlays all other properties in lower layers.
To arrange layer order in the stack you can
- Drag and drop layers.
- Use submenus in Layers > Arrange layers.
Arranging Layers Example
Lets say we have two layers in Wandora, layer1 and layer2. Both layers contain a topic with subject identifier of http://www.wandora.net/Finland describing our home country Finland. Due to merge rule these two topics merge in Wandora. Now lets assume that both topics have different base name. Topic in layer1 has a base name Suomi while the topic in layer layer2 has a base name Finland. Both are valid base names and the question is which base name should Wandora use for the merged topic? Remember that topics may contain only one unscoped base name in Wandora. The answer to the question lies in the order of layer1 and layer2. When layer1 is above layer2 merged topic has base name Suomi and when the layer1 is below the layer2 merged topic has base name Finland. This applies not only to base names but also variant names and occurrences of same type and scope.
Below is a screenshot of Wandora where layer1 overlays layer2. We are viewing topic Suomi. Notice that layer distribution vector 1:1:0 shown in the footer indicates the topic has a merged companion in layer2 but not in layer Base.
Ok, now we switch the layer order and bring layer2 to the top. Topic's base name changes automatically to Finland as the topic in layer2 has different base name than the topic in layer1.
Let's delete the base name in layer2. The base name from layer1 pops up in red. The color indicates the base name does not originate current layer and you can't change it directly. Yes, you can override the base name again but the lower base name stays intact and pop ups again if you delete the overlaying name. To change the lower base name you need to activate the layer base name origins. Layer distribution vector hints which layer to choose.
Analogy drawn earlier between the layer concept of Wandora and graphic design applications may lighten the effect of layer order also. In graphic design applications the graphic element in top layer overlays the elements in lower layers. Similarly the base name in Wandora's top layer overlays base name's of merged topics in lower layers. Similarly the occurrence text of top layer overlays the occurrence of merged topics in lower layers.
