Rails 4 - Layouts only showing half the time with javascript - javascript

I made a little script in javascript to display a different image based on the day, it works fine but half the time when I load the page only the image will be displayed and not the rest of the app(no menus) and the other half everything is working perfectly.
I put the JS code in the index.html.erb file since it's really small, should I put it somewhere else or the problem is elsewhere?
EDIT :
I ended up writing it in coffeescript in the .js.coffee file with an "#" in front of the name of the function and tell call it in the view and I still got the same problem.
View file (app/view/module/index.html.erb)
<script type="text/javascript">
#myfunction();
</script>
function : in app/assets/javascripts/module.js.coffee
#day = ->
today = new Date
number = today.getDay() + 1
document.write '<img src="url' + number +'.jpg">'
return

document.write will erase everything in the html before writing to it, that's why you only see the image.
You should do something like this instead:
placeholder = document.getElementById("placeholder")
placeholder.innerHTML = '<img src="url' + number +'.jpg">'
where placeholder is an existing element in the html with id of "placeholder"

You can't use coffescript in a script tag* - sprockets will not convert the coffee script to javascript which the browser can actually run.
If you had checked the browser console you would have seen that # causes a syntax error in javascript.
SyntaxError: Unexpected token ILLEGAL
When javascript hits a syntax error it will stop executing the script.

Related

How to load a multi line text, edit it and then run as javascript like in eval()?

I need to follow these steps:
Load an script text encoded base64 using Ajax (multiline included before encode).
Edit and Decode using atob()
Run it like in eval().
But I have some issues:
eval() doesn't works because It can't have line break.
I can't use "dataType=script" in Ajax because when dataType is script I just can't edit it before run.
I've tried to remove all comments and line breaks from loaded codes but it doesn't works. I got some errors and I things it's not the best way to do it.
I've tried:
var F = new Function(atob(data));
F();
But it doesn't works.
The only way to works was:
var script = "<script type='text/javascript'> " + atob(data) + " </script>";
$('body').append(script);
But I can't use that because my project will load a lot of requests and it isn't the ideal way since will add a lot of script tags in the DOM. In addition It is not synced with my main codes.

set file attribute filesystemobject javascript

I have created a file as part of a script on a network drive and i am trying to make it hidden so that if the script is run again it should be able to see the file and act on the information contained within it but i am having trouble doing this. what i have so far is:
function doesRegisterExist(oFs, Date, newFolder) {
dbEcho("doesRegisterExist() triggered");
sExpectedRegisterFile = newFolder+"\\Register.txt"
if(oFs.FileExists(sExpectedRegisterFile)==false){
newFile = oFs.OpenTextFile(sExpectedRegisterFile,8,true)
newFile.close()
newReg = oFs.GetFile(sExpectedRegisterFile)
dbEcho(newReg.Attributes)
newReg.Attributes = newReg.Attributes+2
}
}
Windows Script Host does not actually produce an error here and the script runs throgh to competion. the only guides i have found online i have been attempting to translate from VBscript with limited success.
variables passed to this function are roughly declared as such
var oFs = new ActiveXObject("Scripting.FileSystemObject")
var Date = "29-12-2017"
var newFolder = "\\\\File-Server\\path\\to\\folder"
I know ActiveX is a dirty word to a lot of people and i should be shot for even thinking about using it but it really is a perfect fit for what i am trying to do.
Please help.
sExpectedRegisterFolder resolves to \\\\File-Server\\path\\to\\folder\\Register which is a folder and not a file.
I get an Error: file not found when I wrap the code into a try/catch block.
I tested the code on a text file as well, and there it works.
So you're either using the wrong method if you want to set the folder to hidden.
Or you forgot to include the path to the text if you want to change a file to hidden.
( Edit: Or if Register is the name of the file, add the filetype .txt ? )
If you change GetFile to GetFolder as described in https://msdn.microsoft.com/en-us/library/6tkce7xa(v=vs.84).aspx
the folder will get hidden correctly.

read value from txt file in javascript

I have a simple html file in which there's javascript code referring to google charts.
The code I use is this (I'll show the important part):
function drawChart(){
var data = google.visualization
.arrayToDataTable([ ['Label', 'Value'],['Temp', 22.75],]);
// etc...
}
I use a bash command (sed) to replace that 22.75 value with a new one from the last line of a .txt file. However, this throws some errors which I haven't been able to neither correct nor ever identify.
So is there any javascript code that takes that file, extracts the last value and simply displays it on the right place of the code?
UPDATE:
Sorry for the lack of info in this question, I really appreciate all the people that took the time on reading my question. I'll try to fill with more information in the next minutes.
I am able to extract the last line of the .txt file, extract the value on the right part of the '-' symbol and store it in a variable. Then that value is taken to update the html file with a sed command. The error comes when the value is updated but with no value. I guess that happends due to a failed record of temperature in the txt file, then the extracted value is a null. Finally is the html fiel with javascrit code happens to be like this:
(...)['Temp', ],]);
Then the updater can't update the value since due to the way that sed command is written I guess there's no way that it can detect a no-number-value in there. So the html remains without a value all the time.
TXT File structure:
(...)
20:25:03-23.312
20:26:02-23.312
20:27:03-23.375
20:28:03-23.375
20:29:02-23.375
20:30:02-23.312
Bash script:
# (...code...)
lastRecord=`cat /home/pi/scripts/temp_control/logs/"$today".log | awk 'END{print}'`
function rightNow {
lastTemp=`echo $lastRecord | cut -d'-' -f2`
timeOfTemp=`echo $lastRecord | cut -d'-' -f1` # Not used yet
#Command used to update
sed -i "s/['Temp', [0-9]\{1,2\}.[0-9]\{1,3\}]/$lastTemp]/" /var/www/rightnow.html
}
rightNow
You cud get your file just like any other ajax request.
Using javascript
var request = new XMLHttpRequest();
request.open('GET', 'public_path_to_file.txt', false);
request.send();
var textFileContent = request.responseText
Using jQuery
var textFileContent;
$.get('public_path_to_file.txt', function(data) {
textFileContent = data;
});
Whats left is to get the right part from textFileContent. Dependent of the structure of the file we can do this in different ways. Without an example file you are on your own but here is some examples.
If you need the last line
var lines = textFileContent.split("\n");
var lastLine = lines[lines.length - 1];
If you need to use regex
var regex = //* some regex to get your content*//gm;
var result = regex.exec(textFileContent);
// result should now the content who matches your regex
First I'll assume that you ultimately want to read a local file with your browser and your current workflow is something like a local 'bash-script' that
first updates/modifies an inline piece of javascript (inside a locally stored html
file) with the last occurring value retrieved from a local txt-file (using sed)
opens the (just modified html-) file (via commandline) inside a common browser.
Then I assume the sed-route once worked but now doesn't work anymore (probably because the html file has changed?) and now you'd like the inline javascript (in the html file) to fetch that value from the textfile itself and subsequently use it (thus without the need for the 'bash-script'/sed solution.
Thus, the answer (based on above assumptions) to your final question: 'is there any javascript code that takes that file, extracts the last value and simply displays it on the right place of the code?', depends on your final requirement:
are you ok with a file-input where you select the text-file every time you view the html-file?
If your answer is YES, then, (depending on the browser you use) you can read a local file (and work your magic on it's contents).
In modern browsers, using the File API (which was added to the DOM in HTML5) it's now possible for web content to ask the user to select local files, then read the contents of those files.
For example, using FireFox's 'FileReader' you could do:
html:
<input type="file" id="fileinput" multiple />
javascript:
function readAllFiles(evt){
var files = evt.target.files, i = 0, r, f;
if(files){
for(; f = files[i++]; ){
r = new FileReader();
r.onload = (function(f){
return function(e){
alert(e.target.result);
};
})(f);
r.readAsText(f);
}
} else {
alert("Error loading files");
}
}
document.getElementById('fileinput')
.addEventListener('change', readAllFiles, false);
Note that for accessing local files in Chrome you must start Chrome with this switch: chrome --disable-web-security
However,
if the answer is NO (so you want to specify the file, and more importantly it's path, inside the 'code', so you don't have to select the text-file every time your local app runs) then you (usually) can't (because you can't get/set the path, thank the great maker)...
Unless you choose a specific older/unpatched browser (specifically for this task) where you know of a (hack) way to do this anyway (like the IE xml vulnerability or the XMLHTTP vulnerability or etc... you get the picture..).
Some alternative solutions (that don't require you to select the correct textfile over and over again)
Setup a fullblown web (LAMP) server (to use the XMLHttpRequest way as used in aross answer, but this might feel like shooting at a mosquito with a cannon..)
Explore different script languages (but effectively still do the same as your now broken sed-solution)
Combine 1 and 2, choosing from php (the latest version has a small webserver included, you might start/stop it when needed (even in the bash-script workflow) OR using node.js (which is 'javascript' and where you can program/control a small task-specific server in just a couple of lines).
Hope this helps!
Update:
Based on your updated question, comments and request for recommendation, I'd like to suggest to use PHP to dynamically fetch the value from your log txt file and have it generate your html code with inline javascript on the fly (every time you visit the page).
The browser will never see the php code, only what php inserted to your page (in this example the last found value or 0).
You'd rename the rightnow.html file to rightnow.php and modify it (something like) this:
<!DOCTYPE html>
<html><head>
<!-- your header code -->
<script type="text/javascript">
//parts of your javascript
<?php // start php script
$logFile= '/pathToYour/logFile.log'; // <-Modify
if( $fp= #fopen($logFile, "r") ){ // if logfile succesfully opened,
fseek($fp, -30, SEEK_END); // set pointer 30 chars from EOF
$val= array_pop(explode("-", rtrim(fread($fp, 30)))); //get last value
fclose($fp); // close file
}
?> // end php script
function drawChart(){
var data=google.visualization
.arrayToDataTable([ ['Label', 'Value'],
['Temp', <?php echo $val? $val : "0"; ?>],
]); // ^php above inserts value or 0
// etc...
}
//parts of your javascript
</script>
</head><body>
<!-- your body code -->
</body></html>
Note that fopen in combination with setting the filepointer via fseek and sequentially fread-ing from the pointer to EOF does not load the complete logfile (60min * 24hour=1440 lines of 16 bytes=22.5kB at the end of the day) into memory (good for this purpose), but only the last 30 chars (as in this example).
The variable to your logfile and path must still be modified to your situation (I don't know the format of your $today variable).
Depending on your further needs you might want to perform some extra checks/logic on the array of values that explode returns (instead of popping the last value). Or what about modifying the html a little so you could also include the last temperature's time reading, etc. (But this tested piece of code should get you started and explains the procedure of going the php way).
Update:
Since you have chosen to place the last known value of your logfile as in textfile placed inside your public www-root (with a bash script I assume, every minute of the day?), you can now indeed go the 'ajax' way, as answered by aross!
However I want to hint that the code/solutions in all current answers here could be mixed (since you now also have ajax working): instead of ajax-ing (loading) a txt file, you could have php fetch and send this value to the browser on-the-fly/on-demand!
So, instead of requesting http://url_to_my_rpi/file_to_download.txt, you could request http://url_to_my_rpi/read_last_temperature.PHP which should fetch the last known value out of the log-file (set proper security/access) and send it to the browser (set proper headers), just like your text-file did. You wouldn't have to change anything in the html/javascript except the url you request.
The advantage would be (depending on how your current bash-scripts works) that your PI now only does this 'work' (of getting the last value of your logfile) when you are viewing your monitor-page. And that you are not writing that file in your www-root every minute of every day (as I suspect).
The solution achieved, finally, was like this:
I did it with a jQuery statement and reusing the javascript code of Google Charts.
First I added javascript and jQuery tags in the html file:
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script type='text/javascript' src='https://www.google.com/jsapi'></script>
Then I merged jquery code and javascript code that I had in one script:
<script type='text/javascript'>
// Needed this var so that I could use it in other places of the code
var t;
jQuery.get('http://url_to_my_rpi/file_to_download.txt',function(data){
console.log(data)
t=data;
},'text');
google.load('visualization', '1', {packages:['gauge']});
google.setOnLoadCallback(drawChart);
function drawChart() {
t=eval(t);
var data = google.visualization.arrayToDataTable([
['Label', 'Value'],
['Temp', t],]);
// (... more javascript with Google Charts options, display parameters..)
</script>
Finally, and even if it's not listed as the main question, be sure to enable *mod_headers* on your apache and add Header set to apache2.conf file (In my case: /etc/apache2/apache2.conf)
1) Enable the module:
a2enmod headers
2) Add the line on your configuration file
Header set Access-Control-Allow-Origin "*"
3) Restart apache 2
4) In case the 3 steps above didn't work, follow the instrcutions by entering in this website or reinstall apache2.

how do I dump an html page as XML with watir & JavaScript?

I have been trying to create a simple script in FireWatir that will convert the entire current document DOM's (including javascript generated code) to XML representation .
following leads on the web I've came up with this script
require 'rubygems'
require 'firewatir'
browser = Watir::Browser.new
browser.goto('http://www.google.com/')
browser.text_field(:id, 'lst-ib').set('hello')
browser.button(:name, 'btnG').click
puts browser.execute_script("new XMLSerializer().serializeToString(document)")
however, running it in Firefox 3.6 , resulted in this error :
c:/Ruby192/lib/ruby/gems/1.9.1/gems/firewatir-1.9.2/lib/firewatir/jssh_socket.rb
:19:in js_eval': XMLSerializer is not defined (JsshSocket::JSReferenceError)
from c:/Ruby192/lib/ruby/gems/1.9.1/gems/firewatir-1.9.2/lib/firewatir/firefox.rb:136:inexecute_script' from test.rb:9:in `'
if I enter this line:
javascript:window.open('aout:blank').document.write('<pre>' + unescape((new XMLSerializer()).serializeToString(document).replace(/</g, '<')) + '</pre>')
into FF location box, I get a page with the desired XML. so XMLSerializer has to be defined somewhere, its just seems out of reach for my JS code.
how can I get this to work?
Not sure what you mean by "location box", but if that is address bar (the one that says http://stackoverflow.com/... at this page), then try this:
browser.goto "javascript:window.open('aout:blank').document.write('<pre>' + unescape((new XMLSerializer()).serializeToString(document).replace(/</g, '<')) + '</pre>')"
A t the core of it, I suspect this might be an FF thing to do with boundaries of the 'sandbox' that javascript is running in. The browser itself may know about the serializer, but not choose to give javascript any access to it.
However, there may be more than one way to skin the cat. If your second bit of code provides you with a page that is rendered as text in XML syntax, why not do that first, and then just use the resulting page via
puts browser.text

An other way to load a js file in js code

I opened a javaScript file in a javaScript time....
document.write("<script src='newnote.js' type='text/javascript'></script>");
is there an other way to load the js in js code..?
(this file is for loading a popup menu js code , which is loaded after delay by clock js code ... so i want an othe way to loaded it)
When opening a JS file, its code is executed at once - functions are created, code is run, events are set. The only way to 'unload' a Javascript file is to manually undo all the code that has been run as a result of loading the unwanted file: setting all new functions, variables and prototype aditions to undefined (e.g. window.badFunction = undefined, unset all events, remove all new DOM elements..
If you wanted to unload another JS file every time when opening a page, it could in theory be done, but not very easily and if the loaded JS file should change, you would have to update your invalidating file.
What you did isn't like opening a local file in a programming language like C++ or Java. You don't need to close anything.
Is it possible that the script that you are adding to the page (in this case newnote.js) is causing the error you are experiencing?
Instead of the line you used starting with document.write use this instead:
var newnote = document.createElement('script');
newnote.src = "newnote.js";
newnote.type = "text/javascript";
document.documentElement.firstChild.appendChild( newnote );
If you still get your quotes error, then the code inside of newnote.js is messed up.
Don't think this was really what you were asking, but if you used the code I listed above you could then remove this file from your page by calling this:
document.documentElement.firstChild.removeChild( newnote );
One more thought:
If your path to newnote.js is not correct (because it is not in the same directory as the calling page) then the server would return a 404 error page instead of the file. If your browser tried to execute it like javascript, it could throw an error. Try supplying the full URL: http://yoursite.com/js/newnote.js or a root relative one: /js/newnote.js
you are not opening a javascript file, in fact you cannot open any file from local file system, so there is no question of closing. You are inserting a script tag replacing all contents of the document. This would result in fetching newnote.js using the current url with newnote.js replacing anything after last slash.
To include a script you could try this:
var s = document.createElement('script');
s.src = 'newnote.js';
s.type = 'text/javascript';
var head = document.getElementsByTagName('head')[0]
head.appendChild(s);
or like that:
document.write("<script type='text/javascript' src='newnote.js'><\/sc" + "ript>");

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