@@ -6,6 +6,11 @@ module Agents |
||
6 | 6 |
class WebsiteAgent < Agent |
7 | 7 |
cannot_receive_events! |
8 | 8 |
|
9 |
+ default_schedule "every_12h" |
|
10 |
+ |
|
11 |
+ UNIQUENESS_LOOK_BACK = 200 |
|
12 |
+ UNIQUENESS_FACTOR = 3 |
|
13 |
+ |
|
9 | 14 |
description <<-MD |
10 | 15 |
The WebsiteAgent scrapes a website, XML document, or JSON feed and creates Events based on the results. |
11 | 16 |
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@@ -34,17 +39,15 @@ module Agents |
||
34 | 39 |
|
35 | 40 |
Can be configured to use HTTP basic auth by including the `basic_auth` parameter with `username:password`. |
36 | 41 |
|
37 |
- Set `expected_update_period_in_days` to the maximum amount of time that you'd expect to pass between Events being created by this Agent. |
|
42 |
+ Set `expected_update_period_in_days` to the maximum amount of time that you'd expect to pass between Events being created by this Agent. This is only used to set the "working" status. |
|
43 |
+ |
|
44 |
+ Set `uniqueness_look_back` to limit the number of events checked for uniqueness (typically for performance). This defaults to the larger of #{UNIQUENESS_LOOK_BACK} or #{UNIQUENESS_FACTOR}x the number of detected received results. |
|
38 | 45 |
MD |
39 | 46 |
|
40 | 47 |
event_description do |
41 | 48 |
"Events will have the fields you specified. Your options look like:\n\n #{Utils.pretty_print options['extract']}" |
42 | 49 |
end |
43 | 50 |
|
44 |
- default_schedule "every_12h" |
|
45 |
- |
|
46 |
- UNIQUENESS_LOOK_BACK = 30 |
|
47 |
- |
|
48 | 51 |
def working? |
49 | 52 |
event_created_within?(options['expected_update_period_in_days']) && !recent_error_logs? |
50 | 53 |
end |
@@ -54,7 +57,7 @@ module Agents |
||
54 | 57 |
'expected_update_period_in_days' => "2", |
55 | 58 |
'url' => "http://xkcd.com", |
56 | 59 |
'type' => "html", |
57 |
- 'mode' => :on_change, |
|
60 |
+ 'mode' => "on_change", |
|
58 | 61 |
'extract' => { |
59 | 62 |
'url' => {'css' => "#comic img", 'attr' => "src"}, |
60 | 63 |
'title' => {'css' => "#comic img", 'attr' => "title"} |
@@ -63,31 +66,44 @@ module Agents |
||
63 | 66 |
end |
64 | 67 |
|
65 | 68 |
def validate_options |
69 |
+ # Check for required fields |
|
66 | 70 |
errors.add(:base, "url and expected_update_period_in_days are required") unless options['expected_update_period_in_days'].present? && options['url'].present? |
67 | 71 |
if !options['extract'].present? && extraction_type != "json" |
68 | 72 |
errors.add(:base, "extract is required for all types except json") |
69 | 73 |
end |
74 |
+ |
|
75 |
+ # Check for optional fields |
|
76 |
+ if options['mode'].present? |
|
77 |
+ errors.add(:base, "mode must be set to on_change or all") unless %w[on_change all].include?(options['mode']) |
|
78 |
+ end |
|
79 |
+ |
|
80 |
+ if options['expected_update_period_in_days'].present? |
|
81 |
+ errors.add(:base, "Invalid expected_update_period_in_days format") unless is_positive_integer?(options['expected_update_period_in_days']) |
|
82 |
+ end |
|
83 |
+ |
|
84 |
+ if options['uniqueness_look_back'].present? |
|
85 |
+ errors.add(:base, "Invalid uniqueness_look_back format") unless is_positive_integer?(options['uniqueness_look_back']) |
|
86 |
+ end |
|
70 | 87 |
end |
71 | 88 |
|
72 | 89 |
def check |
73 | 90 |
hydra = Typhoeus::Hydra.new |
74 | 91 |
log "Fetching #{options['url']}" |
75 |
- request_opts = {:followlocation => true} |
|
76 |
- if options['basic_auth'].present? |
|
77 |
- request_opts[:userpwd] = options['basic_auth'] |
|
78 |
- end |
|
92 |
+ request_opts = { :followlocation => true } |
|
93 |
+ request_opts[:userpwd] = options['basic_auth'] if options['basic_auth'].present? |
|
79 | 94 |
request = Typhoeus::Request.new(options['url'], request_opts) |
95 |
+ |
|
80 | 96 |
request.on_failure do |response| |
81 | 97 |
error "Failed: #{response.inspect}" |
82 | 98 |
end |
99 |
+ |
|
83 | 100 |
request.on_success do |response| |
84 | 101 |
doc = parse(response.body) |
85 | 102 |
|
86 | 103 |
if extract_full_json? |
87 |
- result = doc |
|
88 |
- if store_payload? result |
|
89 |
- log "Storing new result for '#{name}': #{result.inspect}" |
|
90 |
- create_event :payload => result |
|
104 |
+ if store_payload!(previous_payloads(1), doc) |
|
105 |
+ log "Storing new result for '#{name}': #{doc.inspect}" |
|
106 |
+ create_event :payload => doc |
|
91 | 107 |
end |
92 | 108 |
else |
93 | 109 |
output = {} |
@@ -116,6 +132,7 @@ module Agents |
||
116 | 132 |
return |
117 | 133 |
end |
118 | 134 |
|
135 |
+ old_events = previous_payloads num_unique_lengths.first |
|
119 | 136 |
num_unique_lengths.first.times do |index| |
120 | 137 |
result = {} |
121 | 138 |
options['extract'].keys.each do |name| |
@@ -125,7 +142,7 @@ module Agents |
||
125 | 142 |
end |
126 | 143 |
end |
127 | 144 |
|
128 |
- if store_payload? result |
|
145 |
+ if store_payload!(old_events, result) |
|
129 | 146 |
log "Storing new parsed result for '#{name}': #{result.inspect}" |
130 | 147 |
create_event :payload => result |
131 | 148 |
end |
@@ -138,16 +155,43 @@ module Agents |
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138 | 155 |
|
139 | 156 |
private |
140 | 157 |
|
141 |
- def store_payload? result |
|
142 |
- !options['mode'] || options['mode'].to_s == "all" || (options['mode'].to_s == "on_change" && !previous_payloads.include?(result.to_json)) |
|
158 |
+ # This method returns true if the result should be stored as a new event. |
|
159 |
+ # If mode is set to 'on_change', this method may return false and update an existing |
|
160 |
+ # event to expire further in the future. |
|
161 |
+ def store_payload!(old_events, result) |
|
162 |
+ if !options['mode'].present? |
|
163 |
+ return true |
|
164 |
+ elsif options['mode'].to_s == "all" |
|
165 |
+ return true |
|
166 |
+ elsif options['mode'].to_s == "on_change" |
|
167 |
+ result_json = result.to_json |
|
168 |
+ old_events.each do |old_event| |
|
169 |
+ if old_event.payload.to_json == result_json |
|
170 |
+ old_event.expires_at = new_event_expiration_date |
|
171 |
+ old_event.save! |
|
172 |
+ return false |
|
173 |
+ end |
|
174 |
+ end |
|
175 |
+ return true |
|
176 |
+ end |
|
177 |
+ raise "Illegal options[mode]: " + options['mode'].to_s |
|
143 | 178 |
end |
144 | 179 |
|
145 |
- def previous_payloads |
|
146 |
- events.order("id desc").limit(UNIQUENESS_LOOK_BACK).pluck(:payload).map(&:to_json) if options['mode'].to_s == "on_change" |
|
180 |
+ def previous_payloads(num_events) |
|
181 |
+ if options['uniqueness_look_back'].present? |
|
182 |
+ look_back = options['uniqueness_look_back'].to_i |
|
183 |
+ else |
|
184 |
+ # Larger of UNIQUENESS_FACTOR * num_events and UNIQUENESS_LOOK_BACK |
|
185 |
+ look_back = UNIQUENESS_FACTOR * num_events |
|
186 |
+ if look_back < UNIQUENESS_LOOK_BACK |
|
187 |
+ look_back = UNIQUENESS_LOOK_BACK |
|
188 |
+ end |
|
189 |
+ end |
|
190 |
+ events.order("id desc").limit(look_back) if options['mode'].present? && options['mode'].to_s == "on_change" |
|
147 | 191 |
end |
148 | 192 |
|
149 | 193 |
def extract_full_json? |
150 |
- (!options['extract'].present? && extraction_type == "json") |
|
194 |
+ !options['extract'].present? && extraction_type == "json" |
|
151 | 195 |
end |
152 | 196 |
|
153 | 197 |
def extraction_type |
@@ -174,5 +218,13 @@ module Agents |
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174 | 218 |
raise "Unknown extraction type #{extraction_type}" |
175 | 219 |
end |
176 | 220 |
end |
221 |
+ |
|
222 |
+ def is_positive_integer?(value) |
|
223 |
+ begin |
|
224 |
+ Integer(value) >= 0 |
|
225 |
+ rescue |
|
226 |
+ false |
|
227 |
+ end |
|
228 |
+ end |
|
177 | 229 |
end |
178 | 230 |
end |
@@ -15,15 +15,31 @@ describe Agents::WebsiteAgent do |
||
15 | 15 |
'title' => {'css' => "#comic img", 'attr' => "title"} |
16 | 16 |
} |
17 | 17 |
} |
18 |
- @checker = Agents::WebsiteAgent.new(:name => "xkcd", :options => @site) |
|
18 |
+ @checker = Agents::WebsiteAgent.new(:name => "xkcd", :options => @site, :keep_events_for => 2) |
|
19 | 19 |
@checker.user = users(:bob) |
20 | 20 |
@checker.save! |
21 | 21 |
end |
22 | 22 |
|
23 | 23 |
describe "#check" do |
24 |
- it "should check for changes" do |
|
24 |
+ |
|
25 |
+ it "should validate the integer fields" do |
|
26 |
+ @checker.options['expected_update_period_in_days'] = "nonsense" |
|
27 |
+ lambda { @checker.save! }.should raise_error; |
|
28 |
+ @checker.options['expected_update_period_in_days'] = "2" |
|
29 |
+ @checker.options['uniqueness_look_back'] = "nonsense" |
|
30 |
+ lambda { @checker.save! }.should raise_error; |
|
31 |
+ @checker.options['mode'] = "nonsense" |
|
32 |
+ lambda { @checker.save! }.should raise_error; |
|
33 |
+ @checker.options = @site |
|
34 |
+ end |
|
35 |
+ |
|
36 |
+ it "should check for changes (and update Event.expires_at)" do |
|
25 | 37 |
lambda { @checker.check }.should change { Event.count }.by(1) |
38 |
+ event = Event.last |
|
39 |
+ sleep 2 |
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26 | 40 |
lambda { @checker.check }.should_not change { Event.count } |
41 |
+ update_event = Event.last |
|
42 |
+ update_event.expires_at.should_not == event.expires_at |
|
27 | 43 |
end |
28 | 44 |
|
29 | 45 |
it "should always save events when in :all mode" do |
@@ -35,6 +51,30 @@ describe Agents::WebsiteAgent do |
||
35 | 51 |
}.should change { Event.count }.by(2) |
36 | 52 |
end |
37 | 53 |
|
54 |
+ it "should take uniqueness_look_back into account during deduplication" do |
|
55 |
+ @site['mode'] = 'all' |
|
56 |
+ @checker.options = @site |
|
57 |
+ @checker.check |
|
58 |
+ @checker.check |
|
59 |
+ event = Event.last |
|
60 |
+ event.payload = "{}" |
|
61 |
+ event.save |
|
62 |
+ |
|
63 |
+ lambda { |
|
64 |
+ @site['mode'] = 'on_change' |
|
65 |
+ @site['uniqueness_look_back'] = 2 |
|
66 |
+ @checker.options = @site |
|
67 |
+ @checker.check |
|
68 |
+ }.should_not change { Event.count } |
|
69 |
+ |
|
70 |
+ lambda { |
|
71 |
+ @site['mode'] = 'on_change' |
|
72 |
+ @site['uniqueness_look_back'] = 1 |
|
73 |
+ @checker.options = @site |
|
74 |
+ @checker.check |
|
75 |
+ }.should change { Event.count }.by(1) |
|
76 |
+ end |
|
77 |
+ |
|
38 | 78 |
it "should log an error if the number of results for a set of extraction patterns differs" do |
39 | 79 |
@site['extract']['url']['css'] = "div" |
40 | 80 |
@checker.options = @site |
@@ -79,7 +119,7 @@ describe Agents::WebsiteAgent do |
||
79 | 119 |
'expected_update_period_in_days' => 2, |
80 | 120 |
'type' => "html", |
81 | 121 |
'url' => "http://xkcd.com", |
82 |
- 'mode' => :on_change, |
|
122 |
+ 'mode' => "on_change", |
|
83 | 123 |
'extract' => { |
84 | 124 |
'url' => {'css' => "#topLeft a", 'attr' => "href"}, |
85 | 125 |
'title' => {'css' => "#topLeft a", 'text' => "true"} |
@@ -216,5 +256,4 @@ describe Agents::WebsiteAgent do |
||
216 | 256 |
end |
217 | 257 |
end |
218 | 258 |
end |
219 |
- |
|
220 |
-end |
|
259 |
+end |