41:null 42:["$","title",null,{"children":"Chicago Board of Elections | Hugh | Observable"}] 48:T565,// 3-dimensional array (ward x precinct x candidate) suitable for fast data access and compact serialization to json parseElectionResult = function(doc) { const returnValue = []; const tables = doc.evaluate('//table[position()>1]', doc, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE); for(var i=0; i < tables.snapshotLength; i++) { const table = tables.snapshotItem(i); const tdWard = doc.evaluate('.//tr[1]//td[1]', table, null, XPathResult.FIRST_ORDERED_NODE_TYPE); const ward = parseInt(tdWard.singleNodeValue.innerHTML.replace(/<\/?b>/g, '').split(' ')[1]); returnValue[ward] = []; const trs = doc.evaluate('.//tr[position()>1]', table, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE); for(var j=0; j < trs.snapshotLength; j++) { const tr = trs.snapshotItem(j); const tdPrecinct = doc.evaluate('.//td[1]', tr, null, XPathResult.FIRST_ORDERED_NODE_TYPE); const precinct = parseInt(tdPrecinct.singleNodeValue.innerHTML); returnValue[ward][precinct] = []; const tds = doc.evaluate('.//td[position() mod 2 = 1]', tr, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE); // skip %s for(var k=0; k < tds.snapshotLength - 1; k++) { // skip total const td = tds.snapshotItem(k + 1); const votes = parseInt(td.innerHTML); returnValue[ward][precinct][k] = votes; } } } return returnValue; };49:[{"id":"bbedbf5323d604b39f94e7388b8215020b929783e8682cd1f6ac06598502ea5b78ef30d3d73c980e5ed1da112a468582ce3a2290a0836e8a59026f94d9dcf7de","href":"https://static.observableusercontent.com/files/bbedbf5323d604b39f94e7388b8215020b929783e8682cd1f6ac06598502ea5b78ef30d3d73c980e5ed1da112a468582ce3a2290a0836e8a59026f94d9dcf7de","name":"dataexport.xls","type":"application/octet-stream","lastModified":1606058993405.617,"size":3774574}] 46:{"id":"ed0d145380bb75b5","slug":"chicago-board-of-elections","title":"Chicago Board of Elections","thumbnail":"ce4a99da9b0295baba8f5ff6209486e611e332f48dafa0502ff24ce5db2807e0","access_level":"public","create_time":"$D2020-11-19T20:29:38.388Z","update_time":"$D2024-11-06T20:50:15.285Z","view_time":null,"first_public_time":"$D2020-11-22T00:18:44.433Z","has_unpublished_edits":null,"fork":true,"stars":0,"starred":false,"owner":{"type":"team","id":"19d63ba1bb706983","login":"hughdevlin","name":"Hugh","avatar_url":"https://avatars-next.observableusercontent.com/3855a0736872056a5d9935eac93135690611be581eecc094283af2704b215a2b","tier":"starter_2024","bio":"","following":false},"version":826,"publish_version":826,"role":null,"authored":false,"authors":[{"type":"individual","id":"ee6e4e8d8597a695","login":"hughdevlin","name":"Hugh","avatar_url":"https://avatars-next.observableusercontent.com/3855a0736872056a5d9935eac93135690611be581eecc094283af2704b215a2b","tier":null,"bio":"","following":false}],"members":[{"type":"individual","id":"ee6e4e8d8597a695","login":"hughdevlin","name":"Hugh","avatar_url":"https://avatars-next.observableusercontent.com/3855a0736872056a5d9935eac93135690611be581eecc094283af2704b215a2b","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"titling":"auto","title":"Chicago Board of Elections","cells":[{"id":0,"value":"md`# Chicago Board of Elections`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":514,"value":"md` The [Chicago Board of Election Commissioners (CBOE)](http://chicagoelections.gov) offers election result data as downloads. Tabs and drop-downs at the CBOE [Election Results](https://chicagoelections.gov/en/election-results.html) page, inplemented as [Active Server Pages](https://dotnet.microsoft.com/apps/aspnet), allow customization of the download by year, contest, ward, and precinct.

\nThe downloads are nominally spreadsheets, but are delivered as \\`\\`html\\`\\` files with an \\`\\`.xls\\`\\` file extension which triggers import to a desktop spreadsheet program. These scripts demonstrate creating a [document object model (DOM)](https://www.w3.org/TR/WD-DOM/) from the \\`\\`html\\`\\` and parsing using [xPath](https://www.w3.org/TR/xpath/).\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":677,"value":"md `## Live results`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":681,"value":"md ` This sections demonstrates import of \"live\" data reflecting the most recent results to date as the CBOE tabulates votes.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":2,"value":"proxyUrl = \"https://observable-cors.glitch.me/\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"electionsResultUrl = 'https://chicagoelections.gov/en/data-export.asp?election=251&race=11'","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":566,"value":"md` Two approaches to capturing the download are demonstrated:\n1. using [d3](https://github.com/d3/d3-fetch) and \n2. using browser native [fetch](https://fetch.spec.whatwg.org/).`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":7,"value":"doc = d3.html(proxyUrl + electionsResultUrl) // d3 wrapper for fetch and DOM creation","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":720,"value":"text = fetch(proxyUrl + electionsResultUrl).then(response => response.text())","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":499,"value":"doc2 = (new DOMParser()).parseFromString(text, \"text/html\");","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":575,"value":"md`When all wards and precincts for a contest are selected for download, the resulting payload is an \\`\\`html\\`\\` page with 51 \\`\\`html\\`\\` tables, a City-wide grand totals table followed by a table for each of Chicago's 50 wards.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":249,"value":"tables = doc.evaluate('//table', doc, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE) // grand totals then wards","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":254,"value":"nTables = tables.snapshotLength","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":645,"value":"md `## Parsers`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":643,"value":"md `Two parsers, one for the candidates and one for the wards, using browser-native [xPath](https://www.w3.org/TR/xpath/) but otherwise dependency-free, are the main contributions of this notebook.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":364,"value":"parseCandidates = function(doc) {\n function decode(s) {\n return s.replace(/<\\/?b>/g, '').replace(/&/g, 'and').replace(/''/g, '\"').trim();\n }\n \n const returnValue = [];\n const tds = doc.evaluate('//table[1]//tr[1]//td[position() mod 2 = 0]', doc, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE);\n for(var i=0; i\n\n\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":467,"value":"// 1-dimensional array of objects suitable for tabular presentations\nflatten = function(wpcMatrix, candidates) {\n const returnValue = [];\n for(var ward=1; ward acc + cur);\n returnValue.push(row);\n } \n return returnValue;\n};","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":478,"value":"flattened = flatten(wardPrecinctCandidateMatrix, candidates);","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":641,"value":"md `## Tests`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":692,"value":"md`A sample CBOE \\`\\`dataexport.xls\\`\\`, that of the 2020 Presidential election for all wards and precincts, as of November 9, 2020, is attached for illustration and testing purposes.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":727,"value":"testText = FileAttachment(\"dataexport.xls\").text()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":699,"value":"testDoc = (new DOMParser()).parseFromString(testText, \"text/html\");","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":744,"value":"testCandidates = parseCandidates(testDoc); ","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":746,"value":"assertEqual(testCandidates.length, 6)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":749,"value":"assertEqual(testCandidates[0], \"Joseph R. Biden and Kamala D. Harris\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":755,"value":"testWardPrecinctCandidateMatrix = parseElectionResult(doc2);","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":759,"value":"assertEqual(testWardPrecinctCandidateMatrix.length, 51) // 50 wards and an empty 0th element","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":771,"value":"assertEqual(testWardPrecinctCandidateMatrix[1].length, 45) // 44 precincts in the 1st ward","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":780,"value":"assertEqual(testWardPrecinctCandidateMatrix[1][1].length, 6) // number of candidates","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":788,"value":"assertEqual(testWardPrecinctCandidateMatrix[1][1][0], 667) // votes for 1st candidates in 1st precinct of 1st ward","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":793,"value":"testFlattened = flatten(testWardPrecinctCandidateMatrix, testCandidates)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":797,"value":"assertEqual(testFlattened.length, 2069) // number of precincts","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":811,"value":"assertEqual(testFlattened.find(row => row.ward == 1 && row.precinct == 1)[\"Joseph R. Biden and Kamala D. Harris\"], 667)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":653,"value":"md `## Usage\n\\`\\`import {parseElectionResult, parseCandidates, flatten} from \"@hughdevlin/chicago-board-of-elections\"\\`\\``","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":105,"value":"md `## Libraries`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":43,"value":"d3 = require(\"d3@6\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":636,"value":"import {assertEqual} from '@ariofrio/assert'","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":542,"value":"md `## License `","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":560,"value":"html `\n

This work by Hugh J Devlin CC BY 4.0

`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W49","stdlib":"1"}} 47:"$46:body"