Validator: implemented allowed tag-attribute combinations
The Validator can check if a attribute is allowed in a tag. It does so by associating allowed tags with attributes. This is done in that way, to support also attributes which are allowed for every tag (global attributes), but this is not yet supported. So some functions allow for NULL to be passed and some will still crash. The predicate SH_Validator_check_attr returns whether an attribute is allowed for a specific tag. If tag is NULL, it returns whether an attr is allowed at all, not whether it is allowed for every tag. For this another predicate will be provided, when this is to be implemented. The method SH_Validator_register_attr registers an tag-attr combination. Note, that it will automatically call SH_Validator_register_tag, if the tag doesn't exist. Later it will be possible, to set tag to NULL to register a global attribute, but for now the method will crash. The method SH_Validator_deregister_attr removes a tag-attr combination registered earlier. Note, that deregistering a non existent combination will result in an error. This behaviour is arguable and might be subject to change. When setting only tag to NULL, all tags for this attribute are deregistered. When setting only attr to NULL, all attrs for this tag are deregistered. This might suffer from problems, if this involves some attrs, that are global. Also this will use the internal method remove_tag_for_all_attrs, which has the problem, that it might fail partially. Normally when failing all functions revert the program to the same state, as it was before the call. This function however is different, as if it fails there might be some combinations, that haven't been removed, but others are already. Nevertheless, the validator is still in a valid state, so it is possible to call this function a second time, but it is not sure, which combinations are already deregistered. As the attrs also use the internal strings of the tags, it must be ensured, when a tag is deregistered, that all remaining references are removed, otherwise there would be dangling pointers. Note, that for this also remove_tag_for_all_attrs is used, so the method SH_Validator_deregister_tag suffers from the same problems listed above. Also if this internal method fails, the tag won't be removed at all. Furthermore, the tests for deregistering a tag are still missing.
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- sefht.geany 6 additions, 6 deletionssefht.geany
- src/lib/sefht/validator_attr.c 358 additions, 14 deletionssrc/lib/sefht/validator_attr.c
- src/lib/sefht/validator_attr.h 4 additions, 1 deletionsrc/lib/sefht/validator_attr.h
- src/lib/sefht/validator_attr_data.h 7 additions, 0 deletionssrc/lib/sefht/validator_attr_data.h
- src/lib/sefht/validator_tag.c 19 additions, 0 deletionssrc/lib/sefht/validator_tag.c
- tests/test_validator_attr.c 492 additions, 42 deletionstests/test_validator_attr.c
- todo.txt 5 additions, 0 deletionstodo.txt
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