Flask app for stackview.

app.py

import os

from flask import Flask, url_for
from flask import request, current_app
from flask import jsonify
from flask import render_template
from functools import wraps

from fetch_data import stackview_data, get_by_bib

app = Flask(__name__)

def jsonp(func):
    """
    Taken from:  https://gist.github.com/1094140
    Wraps JSONified output for JSONP requests.
    """
    @wraps(func)
    def decorated_function(*args, **kwargs):
        callback = request.args.get('callback', False)
        if callback:
            data = str(func(*args, **kwargs).data)
            content = str(callback) + '(' + data + ')'
            mimetype = 'application/javascript'
            return current_app.response_class(content, mimetype=mimetype)
        else:
            return func(*args, **kwargs)
    return decorated_function

@app.route('/', methods=['GET'])
@app.route('/<bib>', methods=['GET'])
def stack(bib=None):
    if bib is not None:
        record = get_by_bib(str(bib))
        callnumber = record.get('callnumber')
        #Add shelf location.
        this_title = "%s -- %s" % (record.get('title'), callnumber)
    else:
        callnumber = str(request.args.get('cn', None))
    return render_template(
                'stackview.html',
                callnumber=callnumber,
                title=this_title
            )

@app.route('/data', methods=['GET'])
@jsonp
def stack_view():
    callnumber = str(request.args.get('query', None))
    #import pdb; pdb.set_trace()
    out = stackview_data(callnumber)
    return jsonify(out)

if __name__ == '__main__':
    if os.getenv('DEVBOX') == 'true':
        app.run(
            host='0.0.0.0',
            debug=True
        )
    else:
        app.run()

fetch_data.py

"""
Run Z3950 searches to get the items sorted by call number.

Example Stackview data objects.  
{
            "title": "Blankets",
            "creator": [
                "Craig Thompson"
            ],
            "measurement_page_numeric": 582,
            "measurement_height_numeric": 25,
            "shelfrank": 13,
            "pub_date": "2003",
            "link": "http://holliscatalog.harvard.edu/?itemid=|library/m/aleph|009189638"
        },
        {
            "title": "Persepolis",
            "creator": [
                "Marjane Satrapi"
            ],
            "measurement_page_numeric": 153,
            "measurement_height_numeric": 24,
            "shelfrank": 64,
            "pub_date": "2003",
            "link": "http://holliscatalog.harvard.edu/?itemid=|library/m/aleph|009098946"
        }
"""
import os
import sys
import re

from PyZ3950 import zoom
from PyZ3950.z3950 import ConnectionError
import pymarc 


Z39_SERVER = {
    'host': os.getenv('ZHOST'),
    'port': int(os.getenv('ZPORT')),
    'db': os.getenv('ZDB'),
    'qsyntax': 'PQF',
    'rsyntax': 'OPAC',
    'element_set': 'F',
    'charset': 'utf-8',
} 

PUB_YEAR = re.compile('(?:2[0-9]0u|\?)?[0-9]{3}u|\?')

class Z39Result(object):
    """
        Converts the Z39.50 result to a stackview response.
    """
    def __init__(self, result_set):
        self.result = result_set
    
    def callnumber(self, record):
        """
        Call number routine.  Brown specific.
        """
        call_number = None
        if record['090']:
           call_number = record['090'].format_field()
        elif record['050']:
           call_number = record['050'].format_field()
        return {'callnumber': call_number}

    def get_publication_date(self, record):
        """
        Try to find pub date and convert to Python date object.
        """
        from datetime import datetime, date
        #=008  100315s2010\\\\it\a\\\\\b\\\\001\0\ita\\
        o08 = record['008'].data
        date1 = o08[7:11]
        if PUB_YEAR.search(date1):
            date1 = date1.replace('u', '0')
        #Will convert to date object even though we will report 
        #just the year string.  This will return null for 19uu
        #fields which we don't want to appear in facets. 
        try:
            date_obj = date(year=int(date1), month=1, day=1)
            #Throw out bad data for years greater than two years in 
            #advance. 
            if date_obj.year > (date.today().year + 2):
                return
        except ValueError:
            return
        return str(date_obj.year)

    def physical(self, bib):
        """
        Try to assign a numeric page size. 
        Default to 250 pages.
        """
        phys = bib['300']
        try: 
            pages = phys['a']
            if pages is not None:
                try:
                    pages = int(re.findall(r'[0-9]+', pages)[0])
                except IndexError:
                    pages = 250
            else:
                pages = 250
            try:
                height = int(re.findall(r'[0-9]+', phys['c'])[0]) 
            except IndexError:
                height = 10
            if phys is None:
                return {}
        except TypeError:
            pages = 250
            height = 10

        return {
                "measurement_page_numeric": pages,
                "measurement_height_numeric": height
            }

    def response(self):
        results = {}
        holdings_set = [1]
        for rec in self.result:
            #Read details into pymarc Record object.
            try:
                bib = pymarc.Record(data=rec.data.bibliographicRecord.encoding[1])
            except AttributeError:
                continue
            results['title'] = bib.title()
            #Assuming the record id is in 907 and follows III convention
            results['id'] = bib['907']['a'].lstrip('.')[:8]
            results['link'] = os.getenv('OPAC') + results['id']
            results['pub_date'] = self.get_publication_date(bib)
            results['callnumber'] = self.callnumber(bib)
            au = bib.author()
            if au:
                creator = [au]
            else:
                creator = []
            results['creator'] = creator
            #Get physical description
            results.update(self.physical(bib))
            results.update(self.callnumber(bib))
            #Get item count for shelfrank.
            try:
                holdings_set = rec.data.holdingsData
            except AttributeError:
                pass

        results['items'] = len(holdings_set)
        #Computer a shelfrank based on the number of items in
        #the catalog.
        results['shelfrank'] = self.shelfrank(results['items'])
        return results

    def shelfrank(self, item_count):
        """
        Make a shelf rank based off the number 
        of items/copies held of a given title.
        """
        if item_count == 1:
            sr = 10
        elif (item_count > 1) and (item_count < 3):
            sr = 50
        elif (item_count >= 3) and (item_count < 4):
            sr = 70
        else:
            sr = 100
        return sr


def stackview_data(call_number):
    """
    Run a Z39.50 scan for a particular call number.
    """
    server = Z39_SERVER
    #Open Z39.50 connection
    conn = zoom.Connection(
                server['host'],
                server['port'],
                preferredRecordSyntax=server['rsyntax'],
                elementSetName=server['element_set'],
                databaseName=server['db'],
                charset='utf-8',
                numberOfEntries=int(os.getenv('STACK_SIZE')),
                responsePosition=int(os.getenv('ITEM_POS'))
        )

    params = '@attr 1=16 "%s"' % call_number
    query = zoom.Query(server['qsyntax'], params)
    #Do a scan by call number
    docs = []
    results = conn.scan(query)
    for count, bib in enumerate(results):
        call = bib.get('term')[1]
        csearch = '@attr 1=13 "%s"' % call
        lookup = zoom.Query(server['qsyntax'], csearch)
        result = conn.search(lookup)
        r = Z39Result(result).response()
        docs.append(r)

    conn.close()

    out = {"start": "-1", "limit": 50, "num_found": count}
    out["docs"] = docs
    return out


def get_by_bib(bib_number):
    """
    Get the bibliographic data for a given id number.
    """
    server = Z39_SERVER
    #Open Z39.50 connection
    conn = zoom.Connection(server['host'],
                            server['port'],
                            preferredRecordSyntax=server['rsyntax'],
                            elementSetName=server['element_set'],
                            databaseName=server['db'],
                            charset='utf-8',
                    )
    params = '@attr 1=12 "%s"' % bib_number
    query = zoom.Query(server['qsyntax'], params)
    result = conn.search(query)
    r = Z39Result(result).response()
    conn.close()

    return r

stackview.html

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!-- saved from url=(0068)http://librarylab.law.harvard.edu/projects/stackview/demo/basic.html -->
<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8">


<title>StackView Basic</title>

<link rel="icon" href="http://librarylab.law.harvard.edu/projects/stackview/demo/favicon.ico" type="image/x-icon">

<!-- stackview.css to style the stack -->
<link rel="stylesheet" href="http://librarylab.law.harvard.edu/projects/stackview/demo/lib/jquery.stackview.css" type="text/css">

<!-- stackview.js and all js dependencies -->
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js"></script>
<script type="text/javascript" src="http://librarylab.law.harvard.edu/projects/stackview/demo/lib/jquery.stackview.min.js"></script>


</head>

<body>
        
<div id="stackview"></div>
    
<script type="text/javascript">
    $(function () { 
            $('#stackview').stackView(
                {
                    'url': './data', 
  	    'books_per_page': "1",
		    'start': "30",
                    'ribbon': "Stackview -- {{title}}",
                    'jsonp': true,
                    'search_type': 'cn',
		    'query': "{{callnumber}}",
		    //'search_type': 'loc_sort_order'
                }
            );
    });
</script>


</body>
</html>