Grammar generator from XML

[angelozerr]

Grammar generator from XML

Fixes #778

Signed-off-by: azerr azerr@redhat.com

[angelozerr]

@datho7561 @xorye @fbricon I created a draft PR with the generator (XML -> XSD, XML -> DTD).

The generation is not perfect because it misses some features (like managing maxOccurs, etc), but as it's a big PR, you can start to review the code, the API and comments.

To see what the generator can do it, I suggest you that you read tests for generating XSD and DTD). I will continue to improve the generation of those grammar, but any review feedback are welcome!

[xorye]

Maybe we could have a method ElementDeclaration#addAttribute instead? Just an idea

[angelozerr]

I need to improve attributes cardinality, so please keep like this to get the attribute declaration.

[xorye]

The PR looks good

[angelozerr]

I have improved this PR to consume teh generation in code action for generating xsd and dtd.

Here a demo with noNamespaceSchemaLocation:

Here a demo with DTD

[xorye]

For this example:

<!DOCTYPE root PUBLIC "public-id" "file.dtd">
<root>
    <a>
        <b>hello</b>
        text
    </a>
</root>

after the code action, I have validation errors on the dtd file and xml file:

dtd:

xml:

[datho7561]

I opened issue #788 about multiplicity. @angelozerr, do you think that it makes sense to try to fix this now or in a future PR?

[angelozerr]

For this example:

<!DOCTYPE root PUBLIC "public-id" "file.dtd">
<root>
    <a>
        <b>hello</b>
        text
    </a>
</root>

after the code action, I have validation errors on the dtd file and xml file:

Good catch, fixed!

[angelozerr]

I opened issue #788 about multiplicity. @angelozerr, do you think that it makes sense to try to fix this now or in a future PR?

Fixed!

[datho7561]

Should we also worry about something like this?

<root
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="zero-one-schema.xsd">
    <a>
        <b />
    </a>
    <a></a>
</root>

Generates:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="root">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="a" maxOccurs="unbounded">
          <xs:complexType>
            <xs:sequence>
              <xs:element name="b" />
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

Which makes the second occurrence of <a> invalid.

[angelozerr]

Should we also worry about something like this?

Yes, it was a bug which should be fixed.

The

<root
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="zero-one-schema.xsd">
    <a>
        <b />
    </a>
    <a></a>
</root>

generates now <xs:sequence minOccurs="0"> like this:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="root">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="a" maxOccurs="unbounded">
          <xs:complexType>
            <xs:sequence minOccurs="0">
              <xs:element name="b" minOccurs="0" />
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>