Content.setPreloaded - Code Metrics - Inspection of "Rewrite Content.setPreloaded for more explicit cac..." - jf-guillou/lcds - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( aae0d8...1c2097 )

by Jeff

created 2016-12-09 13:38 UTC

Content.setPreloaded B

↳ Parent: web/js/frontend.js

Complexity

Conditions	7
Paths	4

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	7
c	1
b	0
f	0
nc	4
nop	1
dl	0
loc	20
rs	8.2222

/** global: updateScreenUrl */

/**
 * Screen class constructor
 * @param {string} updateScreenUrl global screen update checks url
 */
function Screen(updateScreenUrl) {
  this.fields = [];
  this.url = updateScreenUrl;
  this.lastChanges = null;
  this.endAt = null;
  this.nextUrl = null;
  this.stopping = false;
  this.cache = {};
}

/**
 * Ajax GET on updateScreenUrl to check lastChanges timestamp and reload if necessary
 */
Screen.prototype.checkUpdates = function() {
  var s = this;
  $.get(this.url, function(j) {
    if (j.success) {
      if (s.lastChanges == null) {
        s.lastChanges = j.data.lastChanges;
      } else if (s.lastChanges != j.data.lastChanges) {
        s.reload();
        s.nextUrl = null;
        return;
      }

      if (j.data.duration > 0) {
        // Setup next screen
        s.reload(j.data.duration * 1000);
        s.nextUrl = j.data.nextScreenUrl;
      }
    }
  });
}

/**
 * Start Screen reload procedure, checking for every field timeout
 */
Screen.prototype.reload = function(minDuration) {
  var endAt = Date.now() + (minDuration ? minDuration : 0);
  if (this.stopping && this.endAt < endAt) {
    return;
  }

  this.endAt = minDuration ? Date.now() + minDuration : 0;
  this.stopping = true;
  for (var i in this.fields) {
    if (!this.fields.hasOwnProperty(i)) {
      continue;
    }
    var f = this.fields[i];
    if (f.timeout && f.endAt > this.endAt) {
      this.endAt = f.endAt;
    }
  }

  if (this.endAt === 0) {
    this.doReload();
  }
}

/**
 * Actual Screen reload action
 */
Screen.prototype.doReload = function() {
  if (this.nextUrl) {
    window.location = this.nextUrl;
  } else {
    window.location.reload();
  }
}

/**
 * Check every field for content
 * @param  {Content} data 
 * @return {boolean} content is displayed
 */
Screen.prototype.displaysData = function(data) {
  return this.fields.filter(function(field) {
    return field.current && field.current.data == data;
  }).length > 0;
}

/**
 * Content class constructor
 * @param {array} c content attributes
 */
function Content(c) {
  this.id = c.id;
  this.data = c.data;
  this.duration = c.duration * 1000;
  this.type = c.type;
  this.src = null;

  if (this.shouldPreload()) {
    this.preload();
  }
}

/**
 * Check if content should be ajax preloaded
 * @return {boolean}
 */
Content.prototype.shouldPreload = function() {
  return this.canPreload() && !this.isPreloading() && !this.isPreloaded();
}

/**
 * Check if content has pre-loadable material
 * @return {boolean} 
 */
Content.prototype.canPreload = function() {
  return this.getResource() && this.type.search(/Video|Image|Agenda/) != -1;
}

/**
 * Extract url from contant data
 * @return {string} resource url
 */
Content.prototype.getResource = function() {
  if (this.src) {
    return this.src;
  }
  var srcMatch = this.data.match(/src="([^"]+)"/);
  if (!srcMatch) {
    return false;
  }
  var src = srcMatch[1];
  if (src.indexOf('/') === 0) {
    src = window.location.origin + src;
  }
  if (src.indexOf('http') !== 0) {
    return false;
  }

  this.src = src;
  return src;
}

/**
 * Check cache for preload status of content
 * @return {Boolean} 
 */
Content.prototype.isPreloaded = function() {
  if (!this.canPreload()) {
    return true;
  }

  var cache = screen.cache[this.getResource()]
  switch (cache) {
    case undefined: // unset
    case false: // preloading
      return false;
    case true: // preloaded without expire
      return true;
    default: // check expire
      return (new Date()).valueOf() < cache;
  }
}

/**
 * Set content cache status
 * @param {string} expires header
 */
Content.prototype.setPreloaded = function(expires) {
  switch (expires) {
    case null:
    case undefined:
      // No Expires header, don't bother with caching
    case true:
      // Force content cache
      screen.cache[this.getResource()] = true;
      break;
    case false:
      // Discard content cache and disallow display
      delete screen.cache[this.getResource()];
      break;
    default:
      var exp = new Date(expires).valueOf();
      var diff = exp - (new Date()).valueOf();
      // Don't check short Expires and add 5 sec to valid Expires
      screen.cache[this.getResource()] = diff < 10000 ? true : exp + 5000;
  }
}

/**
 * Check cache for in progress preloading
 * @return {Boolean}
 */
Content.prototype.isPreloading = function() {
  return screen.cache[this.getResource()] === false;
}

/**
 * Set content preloading status
 * @param {boolean} state is preloading
 */
Content.prototype.setPreloading = function(state) {
  if (state) {
    screen.cache[this.getResource()] = false;
  } else if (this.isPreloading()) {
    delete screen.cache[this.getResource()];
  }
}

/**
 * Ajax call to preload content
 * @return {[type]} [description]
 */
Content.prototype.preload = function() {
  var src = this.getResource();
  if (!src) {
    this.setPreloaded(true);
    return;
  }
  this.setPreloading(true);

  var c = this;
  $.ajax(src).done(function(data, textStatus, jqXHR) {
    c.setPreloaded(jqXHR.getResponseHeader('Expires'));
  }).fail(function() {
    c.setPreloaded(false); // Discard until next Content init
  });
}

/**
 * Field class constructor
 * @param {jQuery.Object} $f field object
 */
function Field($f) {
  this.$field = $f;
  this.id = $f.attr('data-id');
  this.url = $f.attr('data-url');
  this.types = $f.attr('data-types').split(' ');
  this.canUpdate = this.url != null;
  this.contents = [];
  this.previous = null;
  this.current = null;
  this.next = null;
  this.timeout = null;
  this.endAt = null;
}

/**
 * Retrieves contents from backend for this field
 */
Field.prototype.getContents = function() {
  if (!this.canUpdate) {
    return;
  }

  var f = this;
  $.get(this.url, function(j) {
    if (j.success) {
      f.contents = j.next.map(function(c) {
        return new Content(c);
      });
      if (!f.timeout && f.contents.length) {
        f.pickNext();
      }
    } else {
      f.setError(j.message || 'Error');
    }
  });
}

/**
 * Display error in field text
 */
Field.prototype.setError = function(err) {
  this.$field.text(err);
}

/**
 * Randomize order
 */
Field.prototype.randomizeSortContents = function() {
  this.contents = this.contents.sort(function(a, b) {

    return Math.random() - 0.5;
  });
}

/**
 * Loop through field contents to pick next displayable content
 */
Field.prototype.pickNext = function() {
  if (screen.stopping && screen.endAt < Date.now()) { // Stoping screen
    screen.doReload();
    return;
  }

  this.previous = this.current;
  this.current = null;
  var pData = this.previous && this.previous.data;
  // Avoid repeat & other field same content
  this.randomizeSortContents();
  for (var i = 0; i < this.contents.length; i++) {
    var c = this.contents[i];
    // Skip too long or not preloaded content 
    if ((screen.endAt != null && c.duration + Date.now() > screen.endAt) || !c.isPreloaded()) {
      continue;
    }

    if (c.data == pData) {
      // Will repeat, avoid if enough content
      if (this.contents.length < 2) {
        this.next = c;
        break;
      }
      continue;
    }

    if (screen.displaysData(c.data)) {
      // Same content already displayed on other field, avoid if enough content
      if (this.contents.length < 3) {
        this.next = c;
        break;
      }
      continue;
    }

    this.next = c;
  }

  this.display();
}

/**
 * Display next content in field html
 */
Field.prototype.display = function() {
  var f = this;
  if (this.next && this.next.duration > 0) {
    this.current = this.next
    this.next = null;
    this.$field.html(this.current.data);
    this.$field.show();
    if (this.$field.text() != '') {
      this.$field.textfill({
        maxFontPixels: 0,
      });
    }
    if (this.timeout) {
      clearTimeout(this.timeout);
    }
    this.timeout = setTimeout(function() {
      f.pickNext();
    }, this.current.duration);
    this.endAt = this.current.duration + Date.now()
  } else {
    this.timeout = setTimeout(function() {
      f.pickNext();
    }, 2000);
  }
}

/**
 * jQuery.load event
 * Initialize Screen and Fields
 * Setup updates interval timeouts
 */
var screen = null;

function onLoad() {
  screen = new Screen(updateScreenUrl);
  // Init
  $('.field').each(function() {
    var f = new Field($(this));
    f.getContents();
    screen.fields.push(f);
  });

  // Setup content updates loop
  setInterval(function() {
    for (var f in screen.fields) {
      if (screen.fields.hasOwnProperty(f)) {
        screen.fields[f].getContents();
      }
    }
    screen.checkUpdates();
  }, 60000);
  screen.checkUpdates();
}

// Run
$(onLoad);


1			/** global: updateScreenUrl */
2
3			/**
4			* Screen class constructor
5			* @param {string} updateScreenUrl global screen update checks url
6			*/
7			function Screen(updateScreenUrl) {
8			this.fields = [];
9			this.url = updateScreenUrl;
10			this.lastChanges = null;
11			this.endAt = null;
12			this.nextUrl = null;
13			this.stopping = false;
14			this.cache = {};
15			}
16
17			/**
18			* Ajax GET on updateScreenUrl to check lastChanges timestamp and reload if necessary
19			*/
20			Screen.prototype.checkUpdates = function() {
21			var s = this;
22			$.get(this.url, function(j) {
23			if (j.success) {
24			if (s.lastChanges == null) {
25			s.lastChanges = j.data.lastChanges;
26			} else if (s.lastChanges != j.data.lastChanges) {
27			s.reload();
28			s.nextUrl = null;
29			return;
30			}
31
32			if (j.data.duration > 0) {
33			// Setup next screen
34			s.reload(j.data.duration * 1000);
35			s.nextUrl = j.data.nextScreenUrl;
36			}
37			}
38			});
39			}
40
41			/**
42			* Start Screen reload procedure, checking for every field timeout
43			*/
44			Screen.prototype.reload = function(minDuration) {
45			var endAt = Date.now() + (minDuration ? minDuration : 0);
46			if (this.stopping && this.endAt < endAt) {
47			return;
48			}
49
50			this.endAt = minDuration ? Date.now() + minDuration : 0;
51			this.stopping = true;
52			for (var i in this.fields) {
53			if (!this.fields.hasOwnProperty(i)) {
54			continue;
55			}
56			var f = this.fields[i];
57			if (f.timeout && f.endAt > this.endAt) {
58			this.endAt = f.endAt;
59			}
60			}
61
62			if (this.endAt === 0) {
63			this.doReload();
64			}
65			}
66
67			/**
68			* Actual Screen reload action
69			*/
70			Screen.prototype.doReload = function() {
71			if (this.nextUrl) {
72			window.location = this.nextUrl;
73			} else {
74			window.location.reload();
75			}
76			}
77
78			/**
79			* Check every field for content
80			* @param {Content} data
81			* @return {boolean} content is displayed
82			*/
83			Screen.prototype.displaysData = function(data) {
84			return this.fields.filter(function(field) {
85			return field.current && field.current.data == data;
86			}).length > 0;
87			}
88
89			/**
90			* Content class constructor
91			* @param {array} c content attributes
92			*/
93			function Content(c) {
94			this.id = c.id;
95			this.data = c.data;
96			this.duration = c.duration * 1000;
97			this.type = c.type;
98			this.src = null;
99
100			if (this.shouldPreload()) {
101			this.preload();
102			}
103			}
104
105			/**
106			* Check if content should be ajax preloaded
107			* @return {boolean}
108			*/
109			Content.prototype.shouldPreload = function() {
110			return this.canPreload() && !this.isPreloading() && !this.isPreloaded();
111			}
112
113			/**
114			* Check if content has pre-loadable material
115			* @return {boolean}
116			*/
117			Content.prototype.canPreload = function() {
118			return this.getResource() && this.type.search(/Video\|Image\|Agenda/) != -1;
119			}
120
121			/**
122			* Extract url from contant data
123			* @return {string} resource url
124			*/
125			Content.prototype.getResource = function() {
126			if (this.src) {
127			return this.src;
128			}
129			var srcMatch = this.data.match(/src="([^"]+)"/);
130			if (!srcMatch) {
131			return false;
132			}
133			var src = srcMatch[1];
134			if (src.indexOf('/') === 0) {
135			src = window.location.origin + src;
136			}
137			if (src.indexOf('http') !== 0) {
138			return false;
139			}
140
141			this.src = src;
142			return src;
143			}
144
145			/**
146			* Check cache for preload status of content
147			* @return {Boolean}
148			*/
149			Content.prototype.isPreloaded = function() {
150			if (!this.canPreload()) {
151			return true;
152			}
153
154			var cache = screen.cache[this.getResource()]
155			switch (cache) {
156			case undefined: // unset
157			case false: // preloading
158			return false;
159			case true: // preloaded without expire
160			return true;
161			default: // check expire
162			return (new Date()).valueOf() < cache;
163			}
164			}
165
166			/**
167			* Set content cache status
168			* @param {string} expires header
169			*/
170			Content.prototype.setPreloaded = function(expires) {
171			switch (expires) {
172			case null:
173			case undefined:
174			// No Expires header, don't bother with caching
175			case true:
176			// Force content cache
177			screen.cache[this.getResource()] = true;
178			break;
179			case false:
180			// Discard content cache and disallow display
181			delete screen.cache[this.getResource()];
182			break;
183			default:
184			var exp = new Date(expires).valueOf();
185			var diff = exp - (new Date()).valueOf();
186			// Don't check short Expires and add 5 sec to valid Expires
187			screen.cache[this.getResource()] = diff < 10000 ? true : exp + 5000;
188			}
189			}
190
191			/**
192			* Check cache for in progress preloading
193			* @return {Boolean}
194			*/
195			Content.prototype.isPreloading = function() {
196			return screen.cache[this.getResource()] === false;
197			}
198
199			/**
200			* Set content preloading status
201			* @param {boolean} state is preloading
202			*/
203			Content.prototype.setPreloading = function(state) {
204			if (state) {
205			screen.cache[this.getResource()] = false;
206			} else if (this.isPreloading()) {
207			delete screen.cache[this.getResource()];
208			}
209			}
210
211			/**
212			* Ajax call to preload content
213			* @return {[type]} [description]
214			*/
215			Content.prototype.preload = function() {
216			var src = this.getResource();
217			if (!src) {
218			this.setPreloaded(true);
219			return;
220			}
221			this.setPreloading(true);
222
223			var c = this;
224			$.ajax(src).done(function(data, textStatus, jqXHR) {
225			c.setPreloaded(jqXHR.getResponseHeader('Expires'));
226			}).fail(function() {
227			c.setPreloaded(false); // Discard until next Content init
228			});
229			}
230
231			/**
232			* Field class constructor
233			* @param {jQuery.Object} $f field object
234			*/
235			function Field($f) {
236			this.$field = $f;
237			this.id = $f.attr('data-id');
238			this.url = $f.attr('data-url');
239			this.types = $f.attr('data-types').split(' ');
240			this.canUpdate = this.url != null;
241			this.contents = [];
242			this.previous = null;
243			this.current = null;
244			this.next = null;
245			this.timeout = null;
246			this.endAt = null;
247			}
248
249			/**
250			* Retrieves contents from backend for this field
251			*/
252			Field.prototype.getContents = function() {
253			if (!this.canUpdate) {
254			return;
255			}
256
257			var f = this;
258			$.get(this.url, function(j) {
259			if (j.success) {
260			f.contents = j.next.map(function(c) {
261			return new Content(c);
262			});
263			if (!f.timeout && f.contents.length) {
264			f.pickNext();
265			}
266			} else {
267			f.setError(j.message \|\| 'Error');
268			}
269			});
270			}
271
272			/**
273			* Display error in field text
274			*/
275			Field.prototype.setError = function(err) {
276			this.$field.text(err);
277			}
278
279			/**
280			* Randomize order
281			*/
282			Field.prototype.randomizeSortContents = function() {
283			this.contents = this.contents.sort(function(a, b) {
			0 ignored issues – show Unused Code introduced 2016-12-09 13:41 UTC by Report Bug Copy Issue Report The parameter `b` is not used and could be removed. This check looks for parameters in functions that are not used in the function body and are not followed by other parameters which are used inside the function. Loading history... Unused Code introduced 2016-12-09 13:41 UTC by Report Bug Copy Issue Report The parameter `a` is not used and could be removed. This check looks for parameters in functions that are not used in the function body and are not followed by other parameters which are used inside the function. Loading history...
284			return Math.random() - 0.5;
285			});
286			}
287
288			/**
289			* Loop through field contents to pick next displayable content
290			*/
291			Field.prototype.pickNext = function() {
292			if (screen.stopping && screen.endAt < Date.now()) { // Stoping screen
293			screen.doReload();
294			return;
295			}
296
297			this.previous = this.current;
298			this.current = null;
299			var pData = this.previous && this.previous.data;
300			// Avoid repeat & other field same content
301			this.randomizeSortContents();
302			for (var i = 0; i < this.contents.length; i++) {
303			var c = this.contents[i];
304			// Skip too long or not preloaded content
305			if ((screen.endAt != null && c.duration + Date.now() > screen.endAt) \|\| !c.isPreloaded()) {
306			continue;
307			}
308
309			if (c.data == pData) {
310			// Will repeat, avoid if enough content
311			if (this.contents.length < 2) {
312			this.next = c;
313			break;
314			}
315			continue;
316			}
317
318			if (screen.displaysData(c.data)) {
319			// Same content already displayed on other field, avoid if enough content
320			if (this.contents.length < 3) {
321			this.next = c;
322			break;
323			}
324			continue;
325			}
326
327			this.next = c;
328			}
329
330			this.display();
331			}
332
333			/**
334			* Display next content in field html
335			*/
336			Field.prototype.display = function() {
337			var f = this;
338			if (this.next && this.next.duration > 0) {
339			this.current = this.next
340			this.next = null;
341			this.$field.html(this.current.data);
342			this.$field.show();
343			if (this.$field.text() != '') {
344			this.$field.textfill({
345			maxFontPixels: 0,
346			});
347			}
348			if (this.timeout) {
349			clearTimeout(this.timeout);
350			}
351			this.timeout = setTimeout(function() {
352			f.pickNext();
353			}, this.current.duration);
354			this.endAt = this.current.duration + Date.now()
355			} else {
356			this.timeout = setTimeout(function() {
357			f.pickNext();
358			}, 2000);
359			}
360			}
361
362			/**
363			* jQuery.load event
364			* Initialize Screen and Fields
365			* Setup updates interval timeouts
366			*/
367			var screen = null;
368
369			function onLoad() {
370			screen = new Screen(updateScreenUrl);
371			// Init
372			$('.field').each(function() {
373			var f = new Field($(this));
374			f.getContents();
375			screen.fields.push(f);
376			});
377
378			// Setup content updates loop
379			setInterval(function() {
380			for (var f in screen.fields) {
381			if (screen.fields.hasOwnProperty(f)) {
382			screen.fields[f].getContents();
383			}
384			}
385			screen.checkUpdates();
386			}, 60000);
387			screen.checkUpdates();
388			}
389
390			// Run
391			$(onLoad);
392

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