Coverage for portality/view/openurl.py: 91%

1import re 

2from flask import Blueprint, request, redirect, url_for, render_template, abort 

3from portality.models import OpenURLRequest 

4from portality.lib import plausible 

5from portality.core import app 

6from urllib.parse import unquote 

7 

8blueprint = Blueprint('openurl', __name__) 

9 

10 

11@blueprint.route("/openurl", methods=["GET", "POST"]) 

12def openurl(): 

13 # check that we've been given some arguments at all 

14 if len(request.values) == 0: 

15 abort(404) 

16 

17 # Decode and unquote the query string, which comes in as bytes. 

18 qs = unquote(request.query_string.decode('utf-8')) 

19 

20 # Validate the query syntax version and build an object representing it 

21 parser_response = parse_query(query=qs, req=request) 

22 

23 # theoretically this can return None, so catch it 

24 if parser_response is None: 

25 abort(404) 

26 

27 # If it's not parsed to an OpenURLRequest, it's a redirect URL to try again. 

28 if type(parser_response) != OpenURLRequest: 

29 return redirect(parser_response, 301) 

30 

31 # Log this request to analytics 

32 plausible.send_event(app.config.get('GA_CATEGORY_OPENURL', 'OpenURL'), 

33 action=parser_response.genre, 

34 label=qs) 

35 

36 # Get the OpenURLRequest object to issue a query and supply a url for the result 

37 result_url = parser_response.get_result_url() 

38 if result_url: 

39 return redirect(result_url) 

40 else: 

41 abort(404) 

42 

43 

44def parse_query(query, req): 

45 """ 

46 Create the model which holds the query 

47 :param query: The query string from the request URL (separated for the sake of analytics) 

48 :param req: an incoming OpenURL request 

49 :return: an object representing the query, or a redirect to the reissued query, or None if failed. 

50 """ 

51 # Check if this is new or old syntax, translate if necessary 

52 if "url_ver=Z39.88-2004" not in query: 

53 app.logger.info("Legacy OpenURL 0.1 request: " + unquote(req.url)) 

54 return old_to_new(req) 

55 

56 app.logger.info("OpenURL 1.0 request: " + unquote(req.url)) 

57 

58 # Wee function to strip of the referent namespace prefix from parameters 

59 rem_ns = lambda x: re.sub('rft.', '', x) 

60 

61 # Pack the list of parameters into a dictionary, while un-escaping the string. 

62 dict_params = {rem_ns(key): value for (key, value) in req.values.items()} 

63 

64 # Create an object to represent this OpenURL request. 

65 try: 

66 query_object = OpenURLRequest(**dict_params) 

67 except: 

68 query_object = None 

69 app.logger.info("Failed to create OpenURLRequest object") 

70 

71 return query_object 

72 

73 

74def old_to_new(req): 

75 """ 

76 Translate the OpenURL 0.1 syntax to 1.0, to provide a redirect. 

77 :param req: An incoming OpenURL request 

78 :return: An OpenURL 1.0 query string 

79 """ 

80 

81 # The meta parameters in the preamble. 

82 params = {'url_ver': 'Z39.88-2004', 'url_ctx_fmt': 'info:ofi/fmt:kev:mtx:ctx', 'rft_val_fmt': 'info:ofi/fmt:kev:mtx:journal'} 

83 

84 # In OpenURL 0.1, jtitle is just title. This function substitutes them. 

85 sub_title = lambda x: re.sub('^title', 'jtitle', x) 

86 

87 # Add referent tags to each parameter, and change title tag using above function 

88 rewritten_params = {"rft." + sub_title(key): value for (key, value) in req.values.items()} 

89 

90 # Add the rewritten parameters to the meta params 

91 params.update(rewritten_params) 

92 

93 return url_for('.openurl', **params) 

94 

95 

96@blueprint.route("/openurl/help") 

97def help(): 

98 return render_template("openurl/help.html") 

99 

100 

101@blueprint.errorhandler(404) 

102def bad_request(e): 

103 return render_template("openurl/404.html"), 404