I am trying to find a string in a javascript array in the transformer of a mirth channel. Mirth throws an error when I try to use indexOf function. My understanding is that indexOf is something that browsers add in, rather than a native part of the javascript language itself. ( How do I check if an array includes an object in JavaScript? )
So is array.indexOf just not supported in Mirth? Is there any way to use .indexOf in Mirth? Maybe an alternate syntax? Or do I need to just loop thru the array to search?
This is how I search arrays in a Mirth js transformer:
var Yak = [];
Yak.push('test');
if(Yak.indexOf('test') != -1)
{
// do something
}
Does this give you error?
Mirth uses the Rhino engine for Javascript, and on some earlier versions of the JVM, indexOf appeared to not be supported on arrays. Since upgrading our JVM to 1.6.23 (or higher), indexOf has started working. However, we still have legacy code that, when searching arrays of strings, I just use a loop each time:
var compareString = "blah";
var index = -1;
for (var i = 0; i < myArray.length; ++i)
{
if (myArray[i] == compareString)
{
index = i;
break;
}
}
If you need to do this frequently, you should be able to use a code template to manually add the indexOf function to Array.
Set the code template to global access, and try out something like this (untested code):
Array.prototype.indexOf = function(var compareObject)
{
for (var i = 0; i < myArray.length; ++i)
{
// I don't think this is actually the right way to compare
if (myArray[i] == compareObject)
{
return i;
}
}
return -1;
}
var arr = ['john',1,'Peter'];
if(arr.indexOf('john') > -1)
{
//match. what to do?
console.log("found");
}
else
{
console.log("not found");//not found .. do something
}
var i = ['a', 'b', 'c']
if(i.indexOf('a') > -1)
{
///do this, if it finds something in the array that matches what inside the indexOf()
}
else
{
//do something else if it theres no match in array
}
Related
imagine I have a list of translations which I want to apply to the same object.
for instance, a list which defines rotation and translation
list = [[10,20],[30,45]]
how to I apply them in a for loop to one object?
I am looking for something like
for (i=list) {
translate([i[0],0,0])
rotate([i[1],0,0])
}
cube([10,1,1]);
obviously, that is the wrong approach...
any ideas?
This could be done by defining a module that steps through the list recursively.
list = [[10,20],[30,45]];
module transform(list, idx = 0) {
if (idx >= len(list)) {
children();
} else {
translate([list[idx][0],0,0])
rotate([list[idx][1],0,0])
transform(list, idx + 1)
children();
}
}
transform(list) cube([10,1,1]);
In programming, there are multiple ways of doing the same problem. The following problem is in regards to palindrome. Though I feel that I am on the right track, I am not able to completely solve the problem to get to requested solution.
What is a palindrome? A word written forward or backward is the same and returns true. Example, "racecar". Hence, I designed the following code in Javascript...
function palindrome(string) {
string = string.toLowerCase();
lowString = string.toLowerCase().split("").reverse().join("");
for (var i=0; i<string.length; i++) {
if (string[i] !== lowString[i]) {
return false;
}
}
}
return true;
}
The above code returns true if Palindrome exists and returns false if not.
Then, the problem says - Given various palindrome in a string or array, please return the longest palindrome. So, I wrote the following:
function longestPalindrome(newstring) {
splitString = newString.split(" ");
for (var i=0; i < splitString; i++) {
if (splitString[i] == palindrome(splitString[i]) {
console.log(splitString[i]);
}
}
}
longestPalindrome("This is a racecar ada");'
But in the above code, I am not able to get the required outcome because I believe I am not calling the function correctly.
I would appreciate clear directions or even a solution built off of my track as well as the track you deem fittest.
I'm using getElementsByTagName to return all the select lists on a page - is it possible to then filter these based upon an option value, ie of the first or second item in the list?
The reason is that for reasons I won't go into here there are a block of select lists with number values (1,2,3,4,5 etc) and others which have text values (Blue and Black, Red and Black etc) and I only want the scripting I have to run on the ones with numerical values. I can't add a class to them which would more easily let me do this however I can be certain that the first option value in the list will be "1".
Therefore is there a way to filter the returned list of selects on the page by only those whose first option value is "1"?
I am pretty sure that there is a better solution, but for the moment you can try something like:
var allSelect = document.getElementsByTagName("select");
var result = filterBy(allSelect, 0/*0 == The first option*/, "1"/* 1 == the value of the first option*/);
function filterBy(allSelect, index, theValue) {
var result = [];
for (var i = 0; i < allSelect.length; i++) {
if(allSelect[i].options[index].value == theValue ) {
result.push(allSelect[i]);
}
}
return result;
}
I managed to get this working by wrapping a simple IF statement around the action to be performed (in this case, disabling options) as follows:
inputs = document.getElementsByTagName('select');
for (i = 0; i < inputs.length; i++) {
if (inputs[i].options[1].text == 1) {
// perform action required
}
}
No doubt there is a slicker or more economic way to do this but the main thing is it works for me.
I have been using CouchDB for quite sometime without any issues. That is up until now. I recently saw something in my map/reduce results which I had overlooked!
This is before performing a sum on the "avgs" variable. I'm basically trying to find the average of all values pertaining to a particular key. Nothing fancy. The result is as expected.
Note the result for timestamp 1308474660000 (4th row in the table):
Now I sum the "avgs" array. Now here is something that is peculiar about the result. The sum for the key with timestamp 1308474660000 is a null!! Why is CouchDB spitting out nulls for a simple sum? I tried with a custom addition function and its the same problem.
Can someone explain to me why is there this issue with my map/reduce result?
CouchDB version: 1.0.1
UPDATE:
After doing a rereduce I get a reduce overflow error!
Error: reduce_overflow_error
Reduce output must shrink more rapidly: Current output: '["001,1,1,1,1,1,11,1,1,1,1,1,1,11,1,1,1,1,1,1,11,1,1,1,1,1,1,11,1,1,1,1,1,101,1,1,1,1,1,1,11,1,1,1,1'... (first 100 of 396 bytes)
This is my modified reduce function:
function (key, values, rereduce) {
if(!rereduce) {
var avgs = [];
for(var i=values.length-1; i>=0 ; i--) {
avgs.push(Number(values[i][0])/Number(values[i][1]));
}
return avgs;
} else {
return sum(values);
};
}
UPDATE 2:
Well now it has gotten worse. Its selectively rereducing. Also, the ones it has rereduced show wrong results. The length of the value in 4th row for timestamp (1308474660000) should be 2 and not 3.
UPDATE 3:
I finally got it to work. I hadn't understood the specifics of rereduce properly. AFAIK, Couchdb itself decides how to/when to rereduce. In this example, whenever the array was long enough to process, Couchdb would send it to rereduce. So I basically had to sum twice. Once in reduce, and again in rereduce.
function (key, values, rereduce) {
if(!rereduce) {
var avgs = [];
for(var i=values.length-1; i>=0 ; i--) {
avgs.push(Number(values[i][0])/Number(values[i][1]));
}
return sum(avgs);
} else {
return sum(values); //If my understanding of rereduce is correct, it only receives only the avgs that are large enough to not be processed by reduce.
}
}
Your for loop in the reduce function is probably not doing what you think it is. For example, it might be throwing an exception that you did not expect.
You are expecting an array of 2-tuples:
// Expectation
values = [ [value1, total1]
, [value2, total2]
, [value3, total3]
];
During a re-reduce, the function will get old results from itself before.
// Re-reduce values
values = [ avg1
, avg2
, avg3
]
Therefore I would begin by examining how your code works if and when rereduce is true. Perhaps something simple will fix it (although often I have to log() things until I find the problem.)
function(keys, values, rereduce) {
if(rereduce)
return sum(values);
// ... then the same code as before.
}
I will elaborate on my count/sum comment, just in case you are curious.
This code is not tested, but hopefully you will get the idea. The end result is always a simple object {"count":C, "sum":S} and you know the average by computing S / C.
function (key, values, rereduce) {
// Reduce function
var count = 0;
var sum = 0;
var i;
if(!rereduce) {
// `values` stores actual map output
for(i = 0; i < values.length; i++) {
count += Number(values[i][1]);
sum += Number(values[i][0]);
}
return {"count":count, "sum":sum};
}
else {
// `values` stores count/sum objects returned previously.
for(i = 0; i < values.length; i++) {
count += values[i].count;
sum += values[i].sum;
}
return {"count":count, "sum":sum};
}
}
I use the following code to do average. Hope it helps.
function (key, values) {
return sum(values)/values.length;
}
In KRL, I'd like to detect whether a variable is an array or hash so that I know if I need to use the decode or encode operator on it. Is that possible?
I'd like to do something like this:
my_var = var.is_array => var.decode() | my_var
Update
The best way to do this is with the typeof() operator. This is new since the answer, but with the early interpretation of variables, the old way listed in the answer will no longer work.
Another useful operator for examining your data is isnull()
myHash.typeof() => "hash"
myArray.typeof() => "array"
...
The only way that I have figured out how to detect the data structure type is by coercing to a string and then checking to see if the resulting pointer string contains the word 'array' or 'hash'.
'One liner'
myHashIsHash = "#{myHash}".match(re/hash/gi);
myHashIsHash will be true/1
Example app built to demonstrate concept
ruleset a60x547 {
meta {
name "detect-array-or-hash"
description <<
detect-array-or-hash
>>
author "Mike Grace"
logging on
}
global {
myHash = {
"asking":"Mike Farmer",
"question":"detect type"
};
myArray = [0,1,2,3];
}
rule detect_types {
select when pageview ".*"
pre {
myHashIsArray = "#{myHash}".match(re/array/gi);
myHashIsHash = "#{myHash}".match(re/hash/gi);
myArrayIsArray = "#{myArray}".match(re/array/gi);
myArrayIsHash = "#{myArray}".match(re/hash/gi);
hashAsString = "#{myHash}";
arrayAsString = "#{myArray}";
}
{
notify("hash as string",hashAsString) with sticky = true;
notify("array as string",arrayAsString) with sticky = true;
notify("hash is array",myHashIsArray) with sticky = true;
notify("hash is hash",myHashIsHash) with sticky = true;
notify("array is array",myArrayIsArray) with sticky = true;
notify("array is hash",myArrayIsHash) with sticky = true;
}
}
}
Example app in action!