stevedlawrence commented on code in PR #90: URL: https://github.com/apache/daffodil-site/pull/90#discussion_r889020956
########## site/packagingSchemas.adoc: ########## @@ -0,0 +1,84 @@ +:page-layout: page +:url-asciidoctor: http://asciidoctor.org +:keywords: schema package jar +// /////////////////////////////////////////////////////////////////////////// +// +// This file is written in AsciiDoc. +// +// If you can read this comment, your browser is not rendering asciidoc automatically. +// +// You need to install the asciidoc plugin to Chrome or Firefox +// so that this page will be properly rendered for your viewing pleasure. +// +// You can get the plugins by searching the web for 'asciidoc plugin' +// +// You will want to change plugin settings to enable diagrams (they're off by default.) +// +// You need to view this page with Chrome or Firefox. +// +// /////////////////////////////////////////////////////////////////////////// +// +// When editing, please start each sentence on a new line. +// See https://asciidoctor.org/docs/asciidoc-recommended-practices/#one-sentence-per-line[one sentence-per-line writing technique.] +// This makes textual diffs of this file useful in a similar way to the way they work for code. +// +// ////////////////////////////////////////////////////////////////////////// + += Packaging DFDL Schemas for use in Daffodil Applications + +=== Advance Summary + +- The best way to use DFDL schemas is accessing them from Jar files +- Include pre-compiled binary DFDL schema files also in the same Jar file. Review Comment: Should we suggest this? The main argument against this is that pre-compiled binaries are daffodil version specific. So if you update Daffodil you also need to rebuild the jars. ########## site/extensions.adoc: ########## @@ -0,0 +1,60 @@ +:page-layout: page +:url-asciidoctor: http://asciidoctor.org +:keywords: plugins layering UDF charset +// /////////////////////////////////////////////////////////////////////////// +// +// This file is written in AsciiDoc. +// +// If you can read this comment, your browser is not rendering asciidoc automatically. +// +// You need to install the asciidoc plugin to Chrome or Firefox +// so that this page will be properly rendered for your viewing pleasure. +// +// You can get the plugins by searching the web for 'asciidoc plugin' +// +// You will want to change plugin settings to enable diagrams (they're off by default.) +// +// You need to view this page with Chrome or Firefox. +// +// /////////////////////////////////////////////////////////////////////////// +// +// When editing, please start each sentence on a new line. +// See https://asciidoctor.org/docs/asciidoc-recommended-practices/#one-sentence-per-line[one sentence-per-line writing technique.] +// This makes textual diffs of this file useful in a similar way to the way they work for code. +// +// ////////////////////////////////////////////////////////////////////////// + += DFDL Language Extensions in Daffodil + +Daffodil contains numerous extensions to the DFDL v1.0 language. + +Many of these have been, or will be proposed for inclusion in a future version of the DFDL standard. + +This page provides a central starting point for the documentation of these extension features. + +== About Daffodil Plugins + +To provide some new advanced format capabilities such as checksums, compressed or encoded data regions, and user-defined-functions, DFDL schemas sometimes must use Daffodil-specific extensions and incorporate Daffodil plugins that provide the small algorithmic aspects needed by these formats. + +There are 2 kinds of plugins today supported by Daffodil 3.3.0 + +- Layering Transformer (e.g., unzip/zip, verify/recompute checksums) +- User Defined Function (UDF) (e.g., convert mean-sea-level elevation to height-above-ellipsoid) + +There is one additional kind of plugin that will be supported by Daffodil 3.4.0 Review Comment: We'll need to remember to update this page when we release 3.4.0. ########## site/extensions.adoc: ########## @@ -0,0 +1,60 @@ +:page-layout: page +:url-asciidoctor: http://asciidoctor.org +:keywords: plugins layering UDF charset +// /////////////////////////////////////////////////////////////////////////// Review Comment: Is there a way with adoc pages to specify the page title? That way it's added to the tab title and to the top of the page. ########## site/extensions.adoc: ########## @@ -0,0 +1,60 @@ +:page-layout: page +:url-asciidoctor: http://asciidoctor.org +:keywords: plugins layering UDF charset +// /////////////////////////////////////////////////////////////////////////// +// +// This file is written in AsciiDoc. +// +// If you can read this comment, your browser is not rendering asciidoc automatically. +// +// You need to install the asciidoc plugin to Chrome or Firefox +// so that this page will be properly rendered for your viewing pleasure. +// +// You can get the plugins by searching the web for 'asciidoc plugin' +// +// You will want to change plugin settings to enable diagrams (they're off by default.) +// +// You need to view this page with Chrome or Firefox. +// +// /////////////////////////////////////////////////////////////////////////// +// +// When editing, please start each sentence on a new line. +// See https://asciidoctor.org/docs/asciidoc-recommended-practices/#one-sentence-per-line[one sentence-per-line writing technique.] +// This makes textual diffs of this file useful in a similar way to the way they work for code. +// +// ////////////////////////////////////////////////////////////////////////// + += DFDL Language Extensions in Daffodil Review Comment: We already have a https://daffodil.apache.org/dfdl-extensions, should this content be merged with that page? ########## site/packagingSchemas.adoc: ########## @@ -0,0 +1,84 @@ +:page-layout: page +:url-asciidoctor: http://asciidoctor.org +:keywords: schema package jar +// /////////////////////////////////////////////////////////////////////////// +// +// This file is written in AsciiDoc. +// +// If you can read this comment, your browser is not rendering asciidoc automatically. +// +// You need to install the asciidoc plugin to Chrome or Firefox +// so that this page will be properly rendered for your viewing pleasure. +// +// You can get the plugins by searching the web for 'asciidoc plugin' +// +// You will want to change plugin settings to enable diagrams (they're off by default.) +// +// You need to view this page with Chrome or Firefox. +// +// /////////////////////////////////////////////////////////////////////////// +// +// When editing, please start each sentence on a new line. +// See https://asciidoctor.org/docs/asciidoc-recommended-practices/#one-sentence-per-line[one sentence-per-line writing technique.] +// This makes textual diffs of this file useful in a similar way to the way they work for code. +// +// ////////////////////////////////////////////////////////////////////////// + += Packaging DFDL Schemas for use in Daffodil Applications + +=== Advance Summary + +- The best way to use DFDL schemas is accessing them from Jar files +- Include pre-compiled binary DFDL schema files also in the same Jar file. +- Include any Daffodil plugins (class files for compiled scala/java code) required by the DFDL schema also in the same Jar file (with the appropriate META-INF files) and optionally with the source code for the plugins. +- Create _glue_ DFDL schemas that combine other DFDL schemas using managed dependencies (e.g., maven/sbt) on the Jar files of the dependency DFDL schemas. +- Managed dependencies can be used to obtain specific versions of DFDL schemas for applications in the same way that applications obtain and depend upon Java libraries. +- Digital signatures (signed jars) can enhance security by providing trust in the creator of the packaged DFDL schema jar. +- Standard sbt tools facilitate all of this. + + +=== Introduction to DFDL Schema Packaging + +DFDL schemas can be large collections of files. +There are DFDL schemas with over 100 files spread over numerous directories. + +The organization of the files into these directory structures is not arbitrary. +It can be needed to avoid file name clashes and serves the same role as the Java package-name directory structure does for Java programs. +The directory hierarchy defines a Java package-like namespace structure for DFDL schemas. Review Comment: Aren't we trying to move away from this hierarchy? ########## site/packagingSchemas.adoc: ########## @@ -0,0 +1,84 @@ +:page-layout: page +:url-asciidoctor: http://asciidoctor.org +:keywords: schema package jar +// /////////////////////////////////////////////////////////////////////////// +// +// This file is written in AsciiDoc. +// +// If you can read this comment, your browser is not rendering asciidoc automatically. +// +// You need to install the asciidoc plugin to Chrome or Firefox +// so that this page will be properly rendered for your viewing pleasure. +// +// You can get the plugins by searching the web for 'asciidoc plugin' +// +// You will want to change plugin settings to enable diagrams (they're off by default.) +// +// You need to view this page with Chrome or Firefox. +// +// /////////////////////////////////////////////////////////////////////////// +// +// When editing, please start each sentence on a new line. +// See https://asciidoctor.org/docs/asciidoc-recommended-practices/#one-sentence-per-line[one sentence-per-line writing technique.] +// This makes textual diffs of this file useful in a similar way to the way they work for code. +// +// ////////////////////////////////////////////////////////////////////////// + += Packaging DFDL Schemas for use in Daffodil Applications Review Comment: I wonder if this page wants to be merged into the standard project layout? There's seems to be quite a bit of overlap? Also, a normal markdown file seems reasonable. This doesn't use any adoc features. ########## site/extensions.adoc: ########## @@ -0,0 +1,60 @@ +:page-layout: page +:url-asciidoctor: http://asciidoctor.org +:keywords: plugins layering UDF charset +// /////////////////////////////////////////////////////////////////////////// +// +// This file is written in AsciiDoc. +// +// If you can read this comment, your browser is not rendering asciidoc automatically. +// +// You need to install the asciidoc plugin to Chrome or Firefox +// so that this page will be properly rendered for your viewing pleasure. +// +// You can get the plugins by searching the web for 'asciidoc plugin' +// +// You will want to change plugin settings to enable diagrams (they're off by default.) +// +// You need to view this page with Chrome or Firefox. +// Review Comment: Do we need this blurb? All our asciidoc is rendered to HTML, no one should need an extension to view this. Also, it looks like all of this content could just be down with markdown, there's nothing adoc graphs or anything complicated. ########## site/extensions.adoc: ########## @@ -0,0 +1,60 @@ +:page-layout: page +:url-asciidoctor: http://asciidoctor.org +:keywords: plugins layering UDF charset +// /////////////////////////////////////////////////////////////////////////// +// +// This file is written in AsciiDoc. +// +// If you can read this comment, your browser is not rendering asciidoc automatically. +// +// You need to install the asciidoc plugin to Chrome or Firefox +// so that this page will be properly rendered for your viewing pleasure. +// +// You can get the plugins by searching the web for 'asciidoc plugin' +// +// You will want to change plugin settings to enable diagrams (they're off by default.) +// +// You need to view this page with Chrome or Firefox. +// +// /////////////////////////////////////////////////////////////////////////// +// +// When editing, please start each sentence on a new line. +// See https://asciidoctor.org/docs/asciidoc-recommended-practices/#one-sentence-per-line[one sentence-per-line writing technique.] +// This makes textual diffs of this file useful in a similar way to the way they work for code. +// +// ////////////////////////////////////////////////////////////////////////// + += DFDL Language Extensions in Daffodil + +Daffodil contains numerous extensions to the DFDL v1.0 language. + +Many of these have been, or will be proposed for inclusion in a future version of the DFDL standard. + +This page provides a central starting point for the documentation of these extension features. + +== About Daffodil Plugins + +To provide some new advanced format capabilities such as checksums, compressed or encoded data regions, and user-defined-functions, DFDL schemas sometimes must use Daffodil-specific extensions and incorporate Daffodil plugins that provide the small algorithmic aspects needed by these formats. + +There are 2 kinds of plugins today supported by Daffodil 3.3.0 + +- Layering Transformer (e.g., unzip/zip, verify/recompute checksums) +- User Defined Function (UDF) (e.g., convert mean-sea-level elevation to height-above-ellipsoid) + +There is one additional kind of plugin that will be supported by Daffodil 3.4.0 + +- Character Set Definitions (e.g., a specific 5-bit charset used only by a certain format) + +One needs to think of plugins as being part of the DFDL schema of a format, not part of Daffodil. + +Different DFDL schemas for different kinds of data will need their own such plugins. +Hence the plugins, like the DFDL schema files themselves, are used in applications as part of a specific data-processing flow. + +Keeping in the spirit of DFDL in describing a format declaratively, plugins need to be very small pieces of code (ex: a character set definition should be 10 lines of code.) + +Plugins are compiled from Java/Scala code and would commonly be packaged into a jar file which may or may not also contain the DFDL schema files. +The loading of the plugin is enabled using a standard Java technique for class loading where a special META-INF file identifies the jar as containing a particular type of plug-in. + +Configuring an application must put these jar files on the CLASSPATH so that the executing instance of Daffodil for a specific configured data processing flow finds them on the class path for the data format(s) that flow is processing. + +For greater assurance/trust, the plugin jars could be digitally signed by their creators, and applications could verify these signatures (using public keys) as a startup condition. Review Comment: This all seems reasonable. Do you imagine additional pages will be created for and linked to that describe the different plugins in more detail? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
