Finally published journal DOI added

In the project's 'metadata.conf', we also have an option to store the
journal DOI of the project (that will later be printed in the output file
products). So now that the paper's DOI has been set by the journal, it was
time to add it in the project too.

While looking at the usage of the metadata, I noticed that the "Publication
checklist" of 'README-hacking.md' didn't talk about it. In fact, the part
about putting metadata went into a lot of detail without even mentioning
the generic 'print-general-metadata' variable (previously called
'print-copyright') that is created in 'initialize.mk'. So I removed those
extra points and just recommended using this variable for plain-text files
and putting similar info in other formats.

Some other minor changes were made:

 - The metadata now doesn't need the fixed 'https://doi.org/' prefix (to
   make it consistent with the arXiv identifier). Inside 'initialize.mk',
   there are now two variables called 'doi-prefix-url' and
   'arxiv-prefix-url' that contain the fixed prefix.

 - The 'print-copyright' name was clearly outdated for all the extra
   metadata that this variable created (including the copyright). So its
   name was changed to 'print-general-metadata'.

The generic Maneage changes will be taken into Maneage after this (they
were tested here).

3 files changed, 11 insertions, 9 deletions

diff --git a/reproduce/analysis/config/metadata.conf b/reproduce/analysis/config/metadata.conf
index f77ec70..470e429 100644
--- a/reproduce/analysis/config/metadata.conf
+++ b/reproduce/analysis/config/metadata.conf
@@ -13,10 +13,10 @@
 metadata-title = Towards Long-term and Archivable Reproducibility
 
 # DOIs and identifiers.
-metadata-arxiv = 2006.03018
-metadata-doi-zenodo = https://doi.org/10.5281/zenodo.4291207
-metadata-doi-journal =
-metadata-doi = $(metadata-doi-zenodo)
+metadata-arxiv          = 2006.03018
+metadata-doi-zenodo     = 10.5281/zenodo.4291207
+metadata-doi-journal    = 10.1109/MCSE.2021.3072860
+metadata-doi            = $(metadata-doi-journal)
 metadata-git-repository = http://git.maneage.org/paper-concept.git
 
 # DATA Copyright owner and license information.
diff --git a/reproduce/analysis/make/demo-plot.mk b/reproduce/analysis/make/demo-plot.mk
index df7fabc..53e1918 100644
--- a/reproduce/analysis/make/demo-plot.mk
+++ b/reproduce/analysis/make/demo-plot.mk
@@ -45,7 +45,7 @@ $(a2mk20f1c): $(mk20tab3) | $(tex-publish-dir)
 	echo "# Column 3: NUM_PAPERS [count, u32] Total number of papers studied in that year." \
 	     >> $@.tmp
 	echo "# " >> $@.tmp
-	$(call print-copyright, $@.tmp)
+	$(call print-general-metadata, $@.tmp)
 
 
         # Find the maximum number of papers.
diff --git a/reproduce/analysis/make/initialize.mk b/reproduce/analysis/make/initialize.mk
index 168010f..8af3199 100644
--- a/reproduce/analysis/make/initialize.mk
+++ b/reproduce/analysis/make/initialize.mk
@@ -463,16 +463,18 @@ $(data-publish-dir):; mkdir $@
 # This statement can be used in published datasets that are in plain-text
 # format. It assumes you have already put the data-specific statements in
 # its first argument, it will supplement them with general project links.
-print-copyright = \
+doi-prefix-url = https://doi.org
+arxiv-prefix-url = https://arxiv.org/abs
+print-general-metadata = \
 	echo "\# Project title: $(metadata-title)" >> $(1); \
 	echo "\# Git commit (that produced this dataset): $(project-commit-hash)" >> $(1); \
 	echo "\# Project's Git repository: $(metadata-git-repository)" >> $(1); \
 	if [ x$(metadata-arxiv) != x ]; then \
-	  echo "\# Pre-print server: https://arxiv.org/abs/$(metadata-arxiv)" >> $(1); fi; \
+	  echo "\# Pre-print: $(arxiv-prefix-url)/abs/$(metadata-arxiv)" >> $(1); fi; \
 	if [ x$(metadata-doi-journal) != x ]; then \
-	  echo "\# DOI (Journal): $(metadata-doi-journal)" >> $(1); fi; \
+	  echo "\# DOI (Journal): $(doi-prefix-url)/$(metadata-doi-journal)" >> $(1); fi; \
 	if [ x$(metadata-doi-zenodo) != x ]; then \
-	echo "\# DOI (Zenodo): $(metadata-doi-zenodo)" >> $(1); fi; \
+	echo "\# DOI (Zenodo): $(doi-prefix-url)/$(metadata-doi-zenodo)" >> $(1); fi; \
 	echo "\#" >> $(1); \
 	echo "\# Copyright (C) $$(date +%Y) $(metadata-copyright-owner)" >> $(1); \
 	echo "\# Dataset is available under $(metadata-copyright)." >> $(1); \