Merge pull request #205 from nationalarchives/TDRD-442-adr-metadata-d…

…ownload-render-config

ADR for metadata rendering configuration

architecture-decision-records/0036-metadata-rendering-configuration.md

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+# 36. Metadata Render Configuration
+
+**Date**: 2024-11-01
+
+## Context
+
+To support user interaction with record metadata, and exporting metadata, TDR needs to render metadata in a variety of formats, for example HTML, CSV etc.
+
+The rules for rendering metadata are currently stored in a set of database table: `DisplayProperties`. The table contains a set of information to rendering, for example ordering, display name etc.
+
+This approach originally envisaged a limited set of rendering requirements and formats.
+
+With development of additional TDR features, most notably metadata upload, has highlighted a number of limitations with storing rendering rules in a database table:
+* Difficulty in extending and adapting rules with changing product requirements
+* Lack of visibility of the rules for stakeholders: product, design, user research, digital transfer advisers, other Digital Archiving services;
+* Does not fit with the use of JSON schemas for validation of metadata
+* Requires additional calls to the database via API's when rendering on the fly within the application, slowing down the application and putting additional load on TDR infrastructure
+
+## Decision
+
+To address the issues with storing metadata rendering rules within a database table the following approach will be adopted.
+
+The rendering rules will be stored in a configuration file (JSON) and this will be provided to clients as a library for use by clients to render metadata in the required format.
+
+The configuration file will be held in a GitHub repository and published as a library to Maven as with the pattern for the Digital Archiving metadata schemas.
+
+## Other Options Considered
+
+Consideration was given to creating an end to end "render engine" that would hold the configration and also render the metadata to the required format.
+
+This was rejected due the complexities of handling formatting within Excel.