For the debug levels DEBUG and ALL, the XML preprocessor writes a trace for what it exactly does.
The following events are traced (the numbers represent the line numbers in the example below):
The start including the view being processed (1)
A list of all binding contexts with the path they are pointing to (2)
Start of processing of a <with> statement including the new variable assignment (3,6)
Evaluation of an <if> or <elseif> statement including the test result (4,10)
Start of processing of a <repeat> statement (8)
Each iteration of the <repeat> statement including the current variable assignment (9)
Start of processing of a <Fragment> statement including the resulting fragment name (7)
Finished processing of any of the following statements: <with>, <if>, <repeat>, <Fragment> (12-17)
If any attribute of any other node has been resolved (5,11)
The finish (18)
Each debug line looks as follows:
[level] message - <node> sap.ui.core.util.XMLPreprocessor
[level] is the number of currently active preprocessor statements. It is incremented each time when the processing of an <if>, <with>, <repeat> or <Fragment> starts. It is decremented when the node is completely processed. <node> is the node being processed with all its attributes.
Example:
#!xml
1 [ 0] Start processing Element sap.ui.core.mvc.XMLView#__xmlview5 (sap.ui.core.sample.ViewTemplate.scenario.Detail) - sap.ui.core.util.XMLPreprocessor
2 [ 0] meta = /dataServices/schema/0/entityContainer/0/entitySet/0 - sap.ui.core.util.XMLPreprocessor
3 [ 1] entityType = /dataServices/schema/0/entityType/0 - <template:with path="meta>entityType" helper="sap.ui.model.odata.AnnotationHelper.gotoEntityType" var="entityType"> sap.ui.core.util.XMLPreprocessor
4 [ 2] test == [object Array] --> true - <template:if test="{entityType>com.sap.vocabularies.UI.v1.LineItem}"> sap.ui.core.util.XMLPreprocessor
5 [ 2] items = {path:'/BusinessPartnerSet', length: 5} - <Table includeItemInSelection="true" mode="SingleSelect" selectionChange="onSelectionChange" items="{= '{path:\'/' + ${meta>name} + '\', length: 5}' }"> sap.ui.core.util.XMLPreprocessor
6 [ 3] target = /dataServices/schema/0/entityType/0/com.sap.vocabularies.UI.v1.LineItem - <template:with path="entityType>com.sap.vocabularies.UI.v1.LineItem" var="target"> sap.ui.core.util.XMLPreprocessor
7 [ 4] fragmentName = sap.ui.core.sample.ViewTemplate.scenario.Table - <core:Fragment fragmentName="sap.ui.core.sample.ViewTemplate.scenario.Table" type="XML"/> sap.ui.core.util.XMLPreprocessor
8 [ 5] Starting - <template:repeat list="{target>}" var="field"> sap.ui.core.util.XMLPreprocessor
9 [ 5] field = /dataServices/schema/0/entityType/0/com.sap.vocabularies.UI.v1.LineItem/0 - <template:repeat list="{target>}" var="field"> sap.ui.core.util.XMLPreprocessor
10 [ 6] test == [object Object] --> true - <template:if test="{field>Value}"> sap.ui.core.util.XMLPreprocessor
11 [ 6] text = ID - <Text text="{path: 'field>Label', formatter: 'sap.ui.model.odata.AnnotationHelper.format'}"/> sap.ui.core.util.XMLPreprocessor
12 [ 6] Finished - </template:if> sap.ui.core.util.XMLPreprocessor
13 [ 5] Finished - </template:repeat> sap.ui.core.util.XMLPreprocessor
14 [ 4] Finished - </core:Fragment> sap.ui.core.util.XMLPreprocessor
15 [ 3] Finished - </template:with> sap.ui.core.util.XMLPreprocessor
16 [ 2] Finished - </template:if> sap.ui.core.util.XMLPreprocessor
17 [ 1] Finished - </template:with> sap.ui.core.util.XMLPreprocessor
18 [ 0] Finished processing Element sap.ui.core.mvc.XMLView#__xmlview5 (sap.ui.core.sample.ViewTemplate.scenario.Detail) - sap.ui.core.util.XMLPreprocessor