An ERmodel based scripting toolset.
This is a new and more capable development of the ERScript concept.
Additional tranformation logic is supported in that it features derived attributes supported by an xpath macro language, more expressive derived relationships and rules for structure eleboration.
It includes all the features of ERScript but also enables the auto-generation of ER diagrams from entity model structure. Diagrams are represented using DiagrammingByEnrichment.
- enable diagram-less entity modelling,
- optionally enable one or more ER(A) diagrams to present a model or part of a model,
- support automatic generation of an ER diagram from the pure structure of an ER model
- support user to improve automated presentation,
- source xslt transforms as rules represented in xml described by rules entity model,
- factor transform logic so that all that can be represented as derivation of entities, relationships and attributes is so represented,
- an example of a derived entity would be a foreign key attribute such as currently created in the ERmodel2.physical_enrichment.module.xslt
- this may be difficult to describe within entity logic
- though maybe it can be constructed by pullback which would be quite something wouldn't it?
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scripts -- contains source scripts for building examples. I might be able to make more separation here but not necesarily so as EntityLogic will be used to build itself.
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src -- contains source code
- metamodel -- contains entity model represented in xml inclusive of rules for derived structure, relationships and attributes.
- xslt -- all source xslt - includes bootstrap xslt used to realise derived structure, relationships and attributes.
- buildscripts -- scripts to build EntityLogic -- currently these use ERSrcipt v1.4.
- xslt -- contains run time xslt
- bin -- contains generated rng file
- temp -- contains temporary files
- docs -- contains generated documents
Contains a rudimentary xslt transformations for
- autogeneration of an instance of the diagram model from a diagram-free entity model
- as at now in August 2022 the input entity model is required to be an instance of ERmodelv1.2 (it is not required to have any diagramming information -- if it has then it should be ignored )
- I am considering pausing this development so that I can progress the pure entity logic idea and re-source this work using entity logic.
- For a time the metamodel of ER logic will be described as an instance of ERmodel v1.4. One advantage of this is so that I can have a diagram of this metamodel.
- includes attributes such as xpath_evaluate which are 'filled in' by xslt as part of a build process. Such attributes as these are derived attributes but is not possible to described such attributes in the model. Would like to extend the model to describe such derived attributes.
- already includes derived (constructed) relationships and supports use of constructed relationships in xpath by way of such as the (derived) attribute xpath_evaluate.
- xpath_evaluate
- assumes existence of keys for entity types (including abstract entity types one would think)
- assumes, therefore, use from xslt (this could change however because I see that the latest Saxon xslt optimises xslt evaluation by building and using desirable keys -- can therefore perhaps remove use of explicit use of keys without taking a performance hit)
- question: how much work would it be to bootstrap xpath evaluate.
- question: if we do a bootstrap of xpath-evaluate how much freedom do we have in how we use it are we
- limited to a static enrichment of a model by its derived features, or are we
- able to include the derivation of attributes and relatuionships in much more comprehensive transformations such as the gemneration of code or of diagrams.
- we should try and enable 2. for this will not rule out 1. which maybe useful for debugging and for documentation.
- use of the xpath 3.0 xsl:evaluate will ease the number of xslt passes required in the support of derived attributes which have values defined by xpath expressions rather than fine grain model. Example attribute 'elementName' which is constructed by the ERmodel2.physical transformation in file ERmodel2.initial_enrichment_module.xslt.