Receive input via base64 encoded JSON

Drop reading grammar from input, because we'd never use it anyway

Dockerfile

@@ -5,6 +5,7 @@ WORKDIR /workdir
 # Install dependencies
 RUN apt-get update && apt-get install -y \
     ca-certificates \
+    jq \
     xvfb \
     && rm -rf /var/lib/apt/lists/*
 

README.md

@@ -26,7 +26,9 @@ To parse a sentence using xle-docker, you need two things:
 You can then execute the following command:
 
 ```bash
-sudo docker run -i xle "in der Arena veranstalten die Ritter ein Turnier ." < /home/mustermann/grammatik.lfg
+sudo docker run \
+     --mount type=bind,source=/home/mustermann/grammatik.lfg,target=/grammar.lfg \
+     xle "in der Arena veranstalten die Ritter ein Turnier ."
 ```
 
 This will take a few seconds. The parses will then be output to the command line using XLE's own XML export format. If you want to store the output in a file, append `> name_of_your_file.xml` at the end of the command.
@@ -38,15 +40,21 @@ Note that the `xle` specified in the `docker run` command is the name of the tag
 </details>
 
 <details>
-<summary>Alternative using mounts</summary>
+<summary>Alternative using a Base64-encoded JSON</summary>
+
+If you don't want to use mounts, you can also create a JSON file that contains the attributes `sentence` and `grammar`, like this (shortened version, we just want to illustrate how to deal with newlines):
+
+```json
+{"sentence":"in der Arena veranstalten die Ritter ein Turnier", "grammar":"DEMO GERMAN CONFIG (1.0)\n    ROOTCAT IP.\n    LEXENTRIES (DEMO GERMAN).\n    RULES (DEMO GERMAN).\n    GOVERNABLERELATIONS SUBJ OBJ OBJ-TH OBL-TH.\n    SEMANTICFUNCTIONS ADJ.\n    NONDISTRIBUTIVES NUM PERS GEND.\n----\n\nDEMO GERMAN RULES (1.0)\n\nIP --> NP: (^ SUBJ) = !;\n       I'\n       (PUNCT).\n\nNP --> { Det N | NP PP: ! $ (^ ADJ); }.\n\nI' --> I VP.\n\n..."} 
+```
 
-The container also allows the Grammar file to be mounted as `/grammar.lfg`, if this is more useful for your specific use case:
+Store the file as `data.json`. You can then run the container like this:
 
 ```bash
-sudo docker run \
-     --mount type=bind,source=/home/mustermann/grammatik.lfg,target=/grammar.lfg \
-     xle "in der Arena veranstalten die Ritter ein Turnier ."
+sudo docker container run xle $(cat data.json | base64 -w0)
 ```
+
+The idea to implement it that way came from [Christian Heusel](https://christian.heusel.eu/), thank you very much!
 </details>
 
 ## :page_with_curl: About

entrypoint.sh

@@ -2,19 +2,22 @@
 #
 # Entrypoint for the xle Docker image.
 # 
-# You need to provide the following information:
-# 1. A sentence to parse as first (and only) command line argument ($1)
-# 2. A grammar to parse with. The grammar is searched first at /grammar.lfg. If no such file exists, the grammar is read from stdin.
+# XLE needs a sentence and a grammar. You can use either of the following two ways to provide them to an xle container:
+# 1) Mount grammar as /grammar.lfg, pass sentence as first and only command line argument ($1)
+# 2) Pass a base64-encoded JSON containing the attributes "sentence" and "grammar" as first and only command line argument ($1) 
 
 if [[ ! -f /grammar.lfg ]]
 then
-    # Use "cat" to read everything stdin has to offer and then use Bash to write it to a file
-    cat > /grammar.lfg
+    JSON=$(echo $1 | base64 -d)
+    SENTENCE=$(echo $JSON | jq -r .sentence)
+    echo $JSON | jq -r .grammar > /grammar.lfg
+else
+    SENTENCE=$1
 fi
 
 # Write xlerc containing instructions to parse
 echo "create-parser /grammar.lfg" > xlerc
-echo "packed-xml-fs { $1 } packed-parses.xml" >> xlerc
+echo "packed-xml-fs { $SENTENCE } packed-parses.xml" >> xlerc
 echo "exit" >> xlerc
 
 # Start XLE (under the X server), this will automatically load xlerc, let it complete the parse and end