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Tag: node.js

Javascript ascii string to hex byte array

I am trying to convert an ASCII string into a byte array. Problem is my code is converting from ASCII to a string array and not a Byte array: This results in: But what I am looking for is: How can I convert to a byte rather than a byte string ? This array is being streamed to a USB

Module not found error in node.js

I am new to node.js, this is my first node application so, please excuse me if I’m asking obvious question. I have a file called utils.js and I need to have functions defined in that file to be available in main.js. So I tried giving require(utils.js) But it is throwing me this error: My main.js is unde…

Catch express bodyParser error

I want to catch the error from the bodyParser() middleware when I send a json object and it is invalid because I want to send a custom response instead of a generic 400 error. This is what I have and it works: But this seems to me a very ugly approach because I’m comparing the error message which could …

assertEqual error on nodeJs

I just started nodejs development. I am testing mongodb driver but repeatedly getting assertEquals has no method. code from sourceRepo Error has no method ‘assertEquals’ How to reolve it? Answer You can use Node’s Assert for this (where it is called equal rather than equal*s*): However, for …

setImmediate vs. nextTick

Node.js version 0.10 was released today and introduced setImmediate. The API changes documentation suggests using it when doing recursive nextTick calls. From what MDN says it seems very similar to process.nextTick. When should I use nextTick and when should I use setImmediate? Answer Use setImmediate if you …

Extract image src from a string

I’m trying to match all the images elements as strings, This is my regex: This works, but I want to extract the src of all the images. So when I execute the regular expression on this String: <img src=”http://static2.ccn.com/ccs/2013/02/img_example.jpg /> it returns: “http://static2.cc…

Get name and line of calling function in node.js

How can one get the name and line of a function that called the current one? I would like to have a rudimentary debugging function like this (with npmlog defining log.debug): When called from another function it would be something like this: For clarity, what I want is essentially analogous to this in Python:…

Copy folder recursively in Node.js

Is there an easier way to copy a folder and all its content without manually doing a sequence of fs.readir, fs.readfile, fs.writefile recursively? I am just wondering if I’m missing a function which would ideally work like this: Regarding this historic question. Note that fs.cp and fs.cpSync can copy fo…

Multiple populates – mongoosejs

Just a simple query, for example with a double ref in the model. Schema / Model Query I already tried something like In fact only one of the populates works. So, how do is get two populates working ? Answer You’re already using the correct syntax of: Perhaps the meal ObjectId from the order isn’t …