marc

README

go-marc

Go package for working with MARC records.

Important

Not all of MARC. Probably not ever. Just the 034 field so far. If you are looking for a general-purpose library for working with MARC records I'd recommend looking at miku/marc21.

Documentation

Tools

$> make cli
go build -mod vendor -o bin/marc-034 cmd/marc-034/main.go
go build -mod vendor -o bin/marc-034d cmd/marc-034d/main.go
go build -mod vendor -o bin/marc-034-convert cmd/marc-034-convert/main.go

marc-034

Parse one or more MARC 034 strings and emit a (S, W, N, E) bounding box for each.

$> ./bin/marc-034 -h
Parse one or more MARC 034 strings and emit a (S, W, N, E) bounding box for each.
Usage:
	 ./bin/marc-034 MARC034(N) MARC034(N)

Currently this only supports hdddmmss (hemisphere-degrees-minutes-seconds) and dddmmss (degrees-minutes-seconds) notation. For example:

$> ./bin/marc-034 '1#$aa$b22000000$dW1800000$eE1800000$fN0840000$gS0700000'
-70,-180,84,180

marc-034-convert

$> ./bin/marc-034-convert -h
Process one or more CSV files containing MARC 034 data and append bounding box information to a new CSV document.
Usage:
	 ./bin/marc-034-convert csv-file(N) csv-file(N)
  -marc-034-column string
    	The name of the CSV column where MARC 034 data is stored. (default "marc_034")
  -max-x-column string
    	The name of the CSV column where the right-side coordinate (max x) of the bounding box should be stored. (default "max_x")
  -max-y-column string
    	The name of the CSV column where the top-side coordinate (max y) of the bounding box should be stored. (default "max_y")
  -min-x-column string
    	The name of the CSV column where the left-side coordinate (min x) of the bounding box should be stored. (default "min_x")
  -min-y-column string
    	The name of the CSV column where the bottom-side coordinate (min y) of the bounding box should be stored. (default "min_y")
  -to-file string
    	The path where your new CSV file should be created.
  -to-stdout
    	Output CSV data to STDOUT.

For example, given in an input CSV file that looks this:

$> cat test.csv
id,marc_034,name
123,1#$aa$b22000000$dW1800000$eE1800000$fN0840000$gS0700000,example
456,1#$aa$b80000$dW0825500$eW0822000$fN0273000$gN0265000,another example

Passing it to the marc-034-convert tool would yield:

$> ./bin/marc-034-convert -to-stdout ./test.csv
id,marc_034,max_x,max_y,min_x,min_y,name
123,1#$aa$b22000000$dW1800000$eE1800000$fN0840000$gS0700000,180,84,-180,-70,example
456,1#$aa$b80000$dW0825500$eW0822000$fN0273000$gN0265000,-82.33333333333333,27.5,-82.91666666666667,26.833333333333332,another example

marc-034d

A web application for converting MARC 034 strings in to bounding boxes (formatted as GeoJSON)

$> ./bin/marc-034d -h
marc-034d is a web application for converting MARC 034 strings in to bounding boxes (formatted as GeoJSON).
Usage:
	 ./bin/marc-034d [options]
  -nextzen-api-key string
    	A valid Nextzen API key (default "xxxxxx")
  -nextzen-style-url string
    	A valid Nextzen style URL (default "/tangram/refill-style.zip")
  -nextzen-tilepack-database string
    	The path to a valid MBTiles database (tilepack) containing Nextzen MVT tiles.
  -nextzen-tilepack-uri string
    	The relative URI to serve Nextzen MVT tiles from a MBTiles database (tilepack). (default "/tilezen/vector/v1/512/all/{z}/{x}/{y}.mvt")
  -server-uri string
    	A valid aaronland/go-http-server URI (default "http://localhost:8080")

For example:

$> ./bin/marc-034d -nextzen-api-key {APIKEY}

2018/01/12 09:12:44 listening on localhost:8080

The marc-034d server exposes the following endpoints:

/ (or "root")

The / (or default) endpoint will display a handy web interface for converting MARC 034 records in to bounding boxes. For example, here's what it looks like querying for 1#$aa$b80000$dW0825500$eW0822000$fN0273000$gN0265000:

/bbox

The /bbox endpoint will return a bounding box for a MARC 034 field as GeoJSON.

$> curl -s 'http://localhost:8080/bbox?034=1%23%24aa$b22000000%24dW1800000%24eE1800000%24fN0840000%24gS0700000' | python -mjson.tool

{
    "bbox": [
        -180,
        -70,
        180,
        84
    ],
    "geometry": {
        "coordinates": [
            [
                [
                    -180,
                    -70
                ],
                [
                    -180,
                    84
                ],
                [
                    180,
                    84
                ],
                [
                    180,
                    -70
                ],
                [
                    -180,
                    -70
                ]
            ]
        ],
        "type": "Polygon"
    },
    "properties": {
        "marc:034": "1#$aa$b22000000$dW1800000$eE1800000$fN0840000$gS0700000"
    },
    "type": "Feature"
}

Note the way the 034 parameter is URL-encoded.

Nextzen, Nextzen API keys and Nextzen "tilepacks"

The default behaviour for the marc-034d application is to use the TangramJS rendering engine in combination with the freely available Nextzen vector tiles. Use of the Nextzen vector tiles requires a valid API key which can be created at:

• https://developers.nextzen.org/.

It is also possible to configure the marc-034d application to use Nextzen vector tile "tilepacks" to serve tile data locally. The tilepacks are just MBTiles databases containing vector tile data compiled using the tilezen/go-tilepacks package.

To use a local tilepack with the marc-034d application pass the path to your database to the -nextzen-tilepack-database flag. For example:

$> ./bin/marc-034d -nextzen-tilepack-database tiles/nextzen-world-2019-1-10.db 
2021/10/23 14:27:33 listening on http://localhost:8080

The application won't perform any differently but if you look "under the hood" you'll see that the vector tile data is being served from the marc-034d application itself.

Notes

It is currently only possible to serve tiles from a single "tilepack" database.

It is not possible to dynamically limit the map to the zoom range and tile extent of a given "tilepack" database. Yet. I'm working on it.

There are precompiled databases with global tile coverage for zoom levels 1-10, 11 and 12 available on the Internet Archive:

• Global tiles, zoom levels 1 through 10 (1.8GB)
• Global tiles, zoom level 11 (3.5GB)
• Global tiles, zoom level 12 (7.9GB)

Command-line flags and environment variables

Command line flags can be set also be set from environment variables. Environment variables for any given command line flag should be formatted as follows:

• Replace all - characters with _
• Upper case the flag name
• Prepend the string with MARC_

For example the equivalent environment variable for the nextzen-api-key flag would be MARC_NEXTZEN_API_KEY.

Docker

Yes, for marc-034d at least.

$> docker build -t marc-034d .

$> docker run -it -p 8080:8080 marc-034d \
	/usr/local/bin/marc-034d \
	-server-uri http://0.0.0.0:8080 \
	-nextzen-api-key {APIKEY} 

The Dockerfile will copy any "tilepacks" (ending in .db) in this package's tiles folder in to the container's /usr/local/data/tiles folder. This allows you to bundle and load local vector tile data with your container application. For example:

$> docker run -it -p 8080:8080 marc-034d \
	/usr/local/bin/marc-034d \
	-server-uri http://0.0.0.0:8080 \
	-nextzen-tilepack-database /usr/local/data/tiles/nextzen-world-2019-1-10.db 

Note that any files ending in .db in the tiles folder are explicitly excluded from any Git commits.

See also

• https://www.loc.gov/marc/bibliographic/bd034.html
• https://github.com/aaronland/go-http-tangramjs
• https://github.com/aaronland/go-http-bootstrap
• https://github.com/aaronland/go-http-server
• https://developers.nextzen.org/

Documentation

Overview

package marc provides methods for working with MARC records.