Source: search/Search.js

  1. import { EventObject } from "../events/EventObject.js";
  3. export { Search }
  5. /**
  6.  * Full-text search base class. Listen on events "prepare", "process", "finished" or "failed"
  7.  * for processing UI preparations and search results. The finished() method is fired
  8.  * even in case of errors.
  9.  *
  10.  * @author rkoppe <roland.koppe@awi.de>
  11.  * @author rhess <robin.hess@awi.de>
  12.  * 
  13.  * @memberof vef.search
  14.  */
  15. class Search extends EventObject {
  17. 	// initialize properties
  18. 	baseUrl = "";
  19. 	searchRequest = null;
  20. 	searchResult = null;
  21. 	page = 0;
  22. 	pages = 0;
  24. 	/**
  25. 	 * Initializes the search aganist the given base URL.
  26. 	 * 
  27. 	 * @param {string} baseUrl 
  28. 	 */
  29. 	constructor(baseUrl) {
  31. 		if (!baseUrl) throw new Error("baseUrl is not set");
  32. 		if (!baseUrl.endsWith('/')) baseUrl += '/';
  34. 		// Initialize EventObject
  35. 		super({
  36. 			"prepare": [],   // pre-processes the given data. Example: create a table header,
  37. 			"process": [],   // Processes the given object record of the search result.
  38. 			"finished": [],  // Fired when the search request finished
  39. 			"failed": []     // Fired if there was an error during the search request.
  40. 		});
  42. 		// Initialize baseUrl
  43. 		this.baseUrl = baseUrl;
  44. 	}
  46. 	/**
  47. 	 * Processes the responseText from the ajax request and
  48. 	 * fires the necessary events for processing
  49. 	 * 
  50. 	 * @private
  51. 	 */
  52. 	processResult_(responseText) {
  53. 		try {
  54. 			// parse respons
  55. 			const data = JSON.parse(responseText);
  56. 			this.searchResult = data;
  58. 			// prepare pages
  59. 			this.page = Math.ceil(data.offset / this.searchRequest.hits) + 1;
  60. 			this.pages = Math.ceil(data.totalHits / this.searchRequest.hits);
  62. 			this.fire("prepare", data);
  64. 			// process
  65. 			const objects = data.records;
  66. 			for (let i = 0; i < objects.length; ++i) {
  67. 				this.fire("process", objects[i]);
  68. 			}
  70. 			this.fire("finished", data);
  71. 		} catch (e) {
  72. 			this.fire("failed", e);
  73. 		}
  74. 	}
  76. 	/**
  77. 	 * Performs the given searchRequest
  78. 	 * 
  79. 	 * @param {SearchRequest} request
  80. 	 * @returns {XMLHttpRequest}
  81. 	 */
  82. 	request(request) {
  83. 		// reset properties
  84. 		this.searchRequest = request;
  85. 		this.searchResult = null;
  86. 		this.page = 0;
  87. 		this.pages = 0;
  89. 		// create request
  90. 		const http = new XMLHttpRequest();
  91. 		http.open("POST", this.baseUrl, true);
  92. 		http.setRequestHeader("Content-Type", 'application/json');
  94. 		http.onreadystatechange = (e) => {
  95. 			if (http.readyState == 4) {
  96. 				if (http.status === 200) {
  97. 					this.processResult_(http.responseText);
  98. 				} else {
  99. 					this.fire("failed", e);
  100. 				}
  101. 			}
  102. 		}
  104. 		http.onerror = (e) => this.fire("failed", e);
  105. 		http.send(JSON.stringify(request));
  107. 		return http;
  108. 	}
  110. 	/**
  111. 	 * Returns the current page number.
  112. 	 * 
  113. 	 * @returns {number} page number
  114. 	 */
  115. 	getPage() {
  116. 		return this.page;
  117. 	}
  119. 	/**
  120. 	 * Returns the previous page number.
  121. 	 * 
  122. 	 * @returns {number} page number
  123. 	 */
  124. 	getPreviousPage() {
  125. 		return this.page == 1 ? 1 : this.page - 1;
  126. 	}
  128. 	/**
  129. 	 * Returns the next page number lower or equals pages.
  130. 	 * 
  131. 	 * @returns {number} page number
  132. 	 */
  133. 	getNextPage() {
  134. 		return this.page >= this.pages ? this.pages : this.page + 1;
  135. 	}
  137. }