1 | (function ($) {
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2 | /***
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3 | * A sample AJAX data store implementation.
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4 | * Right now, it's hooked up to load Hackernews stories, but can
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5 | * easily be extended to support any JSONP-compatible backend that accepts paging parameters.
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6 | */
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7 | function RemoteModel() {
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8 | // private
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9 | var PAGESIZE = 10;
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10 | var data = {length: 0};
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11 | var h_request = null;
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12 | var req = null; // ajax request
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13 |
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14 | // events
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15 | var onDataLoading = new Slick.Event();
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16 | var onDataLoaded = new Slick.Event();
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17 |
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18 |
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19 | function init() {
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20 | }
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21 |
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22 |
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23 | function isDataLoaded(from, to) {
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24 | for (var i = from; i <= to; i++) {
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25 | if (data[i] == undefined || data[i] == null) {
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26 | return false;
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27 | }
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28 | }
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29 |
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30 | return true;
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31 | }
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32 |
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33 |
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34 | function clear() {
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35 | for (var key in data) {
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36 | delete data[key];
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37 | }
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38 | data.length = 0;
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39 | }
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40 |
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41 | function ensureData(from, to) {
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42 | if (req) {
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43 | req.abort();
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44 | for (var i = req.fromPage; i <= req.toPage; i++) {
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45 | data[i * PAGESIZE] = undefined;
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46 | }
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47 | }
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48 |
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49 | if (from < 0) {
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50 | from = 0;
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51 | }
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52 |
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53 | if (data.length > 0) {
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54 | to = Math.min(to, data.length - 1);
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55 | }
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56 |
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57 | var fromPage = Math.floor(from / PAGESIZE);
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58 | var toPage = Math.floor(to / PAGESIZE);
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59 |
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60 | while (data[fromPage * PAGESIZE] !== undefined && fromPage < toPage)
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61 | fromPage++;
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62 |
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63 | while (data[toPage * PAGESIZE] !== undefined && fromPage < toPage)
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64 | toPage--;
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65 |
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66 | if (fromPage > toPage || ((fromPage == toPage) && data[fromPage * PAGESIZE] !== undefined)) {
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67 | // TODO: look-ahead
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68 | onDataLoaded.notify({from: from, to: to});
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69 | return;
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70 | }
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71 |
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72 | var recStart = (fromPage * PAGESIZE);
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73 | var recCount = (((toPage - fromPage) * PAGESIZE) + PAGESIZE);
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74 |
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75 | var url = "https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20rss"
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76 | + "(" + recStart + "%2C" + recCount + ")"
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77 | + "%20where%20url%3D%22http%3A%2F%2Frss.news.yahoo.com%2Frss%2Ftopstories%22"
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78 | + "&format=json";
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79 |
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80 | if (h_request != null) {
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81 | clearTimeout(h_request);
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82 | }
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83 |
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84 | h_request = setTimeout(function () {
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85 | for (var i = fromPage; i <= toPage; i++)
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86 | data[i * PAGESIZE] = null; // null indicates a 'requested but not available yet'
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87 |
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88 | onDataLoading.notify({from: from, to: to});
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89 |
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90 | req = $.jsonp({
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91 | url: url,
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92 | callbackParameter: "callback",
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93 | cache: true,
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94 | success: function (json, textStatus, xOptions) {
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95 | onSuccess(json, recStart);
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96 | },
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97 | error: function () {
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98 | onError(fromPage, toPage);
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99 | }
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100 | });
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101 |
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102 | req.fromPage = fromPage;
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103 | req.toPage = toPage;
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104 | }, 50);
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105 | }
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106 |
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107 |
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108 | function onError(fromPage, toPage) {
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109 | alert("error loading pages " + fromPage + " to " + toPage);
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110 | }
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111 |
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112 | // SAMPLE DATA
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113 | // {
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114 | // "query": {
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115 | // "count": 40,
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116 | // "created": "2015-03-03T00:34:00Z",
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117 | // "lang": "en-US",
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118 | // "results": {
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119 | // "item": [
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120 | // {
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121 | // "title": "Netanyahu assails Iran deal, touts US-Israel ties",
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122 | // "description": "<p><a href=\"http://news.yahoo.com/netanyahu-us-officials-face-off-iran-133539021--politics.html\"><img src=\"http://l2.yimg.com/bt/api/res/1.2/4eoBxbJStrbGAKbmBYOJfg--/YXBwaWQ9eW5ld3M7Zmk9ZmlsbDtoPTg2O3E9NzU7dz0xMzA-/http://media.zenfs.com/en_us/News/ap_webfeeds/2f3a20c2d46d9f096f0f6a706700d430.jpg\" width=\"130\" height=\"86\" alt=\"Israeli Prime Minister Benjamin Netanyahu addresses the 2015 American Israel Public Affairs Committee (AIPAC) Policy Conference in Washington, Monday, March 2, 2015. (AP Photo/Cliff Owen)\" align=\"left\" title=\"Israeli Prime Minister Benjamin Netanyahu addresses the 2015 American Israel Public Affairs Committee (AIPAC) Policy Conference in Washington, Monday, March 2, 2015. (AP Photo/Cliff Owen)\" border=\"0\" /></a>WASHINGTON (AP) — Seeking to lower tensions, Benjamin Netanyahu and U.S. officials cast their dispute over Iran as a family squabble on Monday, even as the Israeli leader claimed President Barack Obama did not — and could not — fully understand his nation's vital security concerns.</p><br clear=\"all\"/>",
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123 | // "link": "http://news.yahoo.com/netanyahu-us-officials-face-off-iran-133539021--politics.html",
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124 | // "pubDate": "Mon, 02 Mar 2015 19:17:36 -0500",
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125 | // "source": {
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126 | // "url": "http://www.ap.org/",
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127 | // "content": "Associated Press"
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128 | // },
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129 | // "guid": {
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130 | // "isPermaLink": "false",
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131 | // "content": "netanyahu-us-officials-face-off-iran-133539021--politics"
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132 | // },
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133 | // "content": {
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134 | // "height": "86",
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135 | // "type": "image/jpeg",
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136 | // "url": "http://l2.yimg.com/bt/api/res/1.2/4eoBxbJStrbGAKbmBYOJfg--/YXBwaWQ9eW5ld3M7Zmk9ZmlsbDtoPTg2O3E9NzU7dz0xMzA-/http://media.zenfs.com/en_us/News/ap_webfeeds/2f3a20c2d46d9f096f0f6a706700d430.jpg",
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137 | // "width": "130"
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138 | // },
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139 | // "text": {
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140 | // "type": "html",
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141 | // "content": "<p><a href=\"http://news.yahoo.com/netanyahu-us-officials-face-off-iran-133539021--politics.html\"><img src=\"http://l2.yimg.com/bt/api/res/1.2/4eoBxbJStrbGAKbmBYOJfg--/YXBwaWQ9eW5ld3M7Zmk9ZmlsbDtoPTg2O3E9NzU7dz0xMzA-/http://media.zenfs.com/en_us/News/ap_webfeeds/2f3a20c2d46d9f096f0f6a706700d430.jpg\" width=\"130\" height=\"86\" alt=\"Israeli Prime Minister Benjamin Netanyahu addresses the 2015 American Israel Public Affairs Committee (AIPAC) Policy Conference in Washington, Monday, March 2, 2015. (AP Photo/Cliff Owen)\" align=\"left\" title=\"Israeli Prime Minister Benjamin Netanyahu addresses the 2015 American Israel Public Affairs Committee (AIPAC) Policy Conference in Washington, Monday, March 2, 2015. (AP Photo/Cliff Owen)\" border=\"0\" /></a>WASHINGTON (AP) — Seeking to lower tensions, Benjamin Netanyahu and U.S. officials cast their dispute over Iran as a family squabble on Monday, even as the Israeli leader claimed President Barack Obama did not — and could not — fully understand his nation's vital security concerns.</p><br clear=\"all\"/>"
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142 | // },
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143 | // "credit": {
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144 | // "role": "publishing company"
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145 | // }
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146 | // },
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147 | // {... },
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148 | // {... },
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149 | // ]
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150 | // }
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151 | // }
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152 | // }
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153 |
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154 | function onSuccess(json, recStart) {
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155 | var recEnd = recStart;
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156 | if (json.query.count > 0) {
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157 | var results = json.query.results.item;
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158 | recEnd = recStart + results.length;
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159 | data.length = 100;// Math.min(parseInt(results.length),1000); // limitation of the API
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160 |
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161 | for (var i = 0; i < results.length; i++) {
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162 | var item = results[i];
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163 |
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164 | item.pubDate = new Date(item.pubDate);
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165 |
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166 | data[recStart + i] = { index: recStart + i };
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167 | data[recStart + i].pubDate = item.pubDate;
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168 | data[recStart + i].title = item.title;
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169 | data[recStart + i].url = item.link;
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170 | data[recStart + i].text = item.description;
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171 | }
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172 | }
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173 | req = null;
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174 |
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175 | onDataLoaded.notify({from: recStart, to: recEnd});
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176 | }
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177 |
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178 |
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179 | function reloadData(from, to) {
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180 | for (var i = from; i <= to; i++)
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181 | delete data[i];
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182 |
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183 | ensureData(from, to);
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184 | }
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185 |
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186 | init();
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187 |
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188 | return {
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189 | // properties
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190 | "data": data,
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191 |
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192 | // methods
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193 | "clear": clear,
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194 | "isDataLoaded": isDataLoaded,
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195 | "ensureData": ensureData,
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196 | "reloadData": reloadData,
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197 |
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198 | // events
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199 | "onDataLoading": onDataLoading,
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200 | "onDataLoaded": onDataLoaded
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201 | };
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202 | }
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203 |
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204 | // Slick.Data.RemoteModel
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205 | $.extend(true, window, { Slick: { Data: { RemoteModel: RemoteModel }}});
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206 | })(jQuery);
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