I thought it’d be interesting to consider Javascript objects which can modify their own behavior over time. A use case for this (what I’m doing) is pages of data, where data is first looked up, then cached in memory, then cleared. A simple case (demonstrated below) is memoization.<\/p>\n
The following query will do an ajax lookup of some data:<\/p>\n
\nfunction loadData() {\n var data;\n\n $.ajax({\n url: \"blocks\/\" + this.block,\n async: false\n }).done(function(blockData) {\n data = blockData.split(\"\\n\")\n for (var i = 0; i < data.length; i++) {\n data[i] = data[i].split(\"\\t\")\n }\n });\n\n return data;\n}\n\nvar x = {block: 'xabnh', getData: loadData}\n\nx.getData();\nArray[2501]\n<\/pre>\nThis shows how one might trigger caching the results. Once retrieved, the cached data is hidden within a closure, and the mechanism for retrieving data is updated. In the case of a memory manager, these pages are later cleared out by replacing the memoization function with a third function, which starts the process all over again.<\/p>\n
\nvar x = {block: 'xabnh', getData: memoize(loadData)}\n\nfunction memoize(getData) {\n return function() {\n console.log('loading');\n var data = getData.apply(this);\n function savedData() {\n console.log('memoized');\n return data;\n }\n this.getData = savedData;\n \n return data;\n }\n}\n\nx.getData()\nloading\nArray[2501]\nx.getData()\nmemoized\nArray[2501]\n<\/pre>\nThere are a few downsides to this approach; data in the closure is hidden from inspection, the current state of the object is hidden, and can change quickly. A generalized approach to this problem might pass an object into the getData function to show state or trigger a debug mode.<\/p>\n","protected":false},"excerpt":{"rendered":"
I thought it’d be interesting to consider Javascript objects which can modify their own behavior over time. A use case for this (what I’m doing) is pages of data, where data is first looked up, then cached in memory, then cleared. A simple case (demonstrated below) is memoization. The following query will do an ajax … <\/p>\n