1 | 'use strict'
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2 |
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3 | module.exports = search
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4 |
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5 | var toString = require('mdast-util-to-string')
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6 | var visit = require('unist-util-visit')
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7 | var is = require('unist-util-is')
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8 | var slugs = require('github-slugger')()
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9 |
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10 | var HEADING = 'heading'
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11 |
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12 |
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13 | function search(root, expression, settings) {
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14 | var length = root.children.length
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15 | var depth = null
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16 | var lookingForToc = expression !== null
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17 | var maxDepth = settings.maxDepth || 6
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18 | var parents = settings.parents || root
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19 | var map = []
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20 | var headingIndex
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21 | var closingIndex
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22 |
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23 | if (!lookingForToc) {
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24 | headingIndex = -1
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25 | }
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26 |
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27 | slugs.reset()
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28 |
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29 |
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30 |
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31 | visit(root, HEADING, onheading)
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32 |
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33 | if (headingIndex && !closingIndex) {
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34 | closingIndex = length + 1
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35 | }
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36 |
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37 | if (headingIndex === undefined) {
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38 | headingIndex = -1
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39 | closingIndex = -1
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40 | map = []
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41 | }
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42 |
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43 | return {index: headingIndex, endIndex: closingIndex, map: map}
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44 |
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45 | function onheading(child, index, parent) {
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46 | var value = toString(child)
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47 | var id = child.data && child.data.hProperties && child.data.hProperties.id
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48 |
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49 | if (!is(parents, parent)) {
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50 | return
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51 | }
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52 |
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53 | if (lookingForToc) {
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54 | if (isClosingHeading(child, depth)) {
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55 | closingIndex = index
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56 | lookingForToc = false
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57 | }
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58 |
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59 | if (isOpeningHeading(child, depth, expression)) {
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60 | headingIndex = index + 1
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61 | depth = child.depth
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62 | }
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63 | }
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64 |
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65 | if (!lookingForToc && value && child.depth <= maxDepth) {
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66 | map.push({
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67 | depth: child.depth,
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68 | children: child.children,
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69 | id: slugs.slug(id || value)
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70 | })
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71 | }
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72 | }
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73 | }
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74 |
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75 |
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76 | function isOpeningHeading(node, depth, expression) {
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77 | return (
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78 | depth === null &&
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79 | node &&
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80 | node.type === HEADING &&
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81 | expression.test(toString(node))
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82 | )
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83 | }
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84 |
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85 |
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86 | function isClosingHeading(node, depth) {
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87 | return depth && node && node.type === HEADING && node.depth <= depth
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88 | }
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