Develop Reference

images not getting loaded

I'm trying to load a bunch of png images that are in a folder in my project. I'm using a function that takes in an array of strings that signify the name of the actual images.
The actual html that comes up in the console seems correct, however the images don't get loaded. The weird thing is, if I hard code in the html with the src of one of the images, the src in the inspector comes up as 'name.93439.png' with random numbers in between the name and the file extension, and the image shows up. But the source I am injecting in the javascript using template strings is no different than what I am putting into the html when I hard code it.
So is there something I'm missing here with loading images? Why does hard coding it in work, but when I try using JS it doesn't give the same results? Code below:
FILE STRUCTURE:
index.html
/src
index.js
/assets
/images
...{all of the images}.png
function loadImages(names) {
names.forEach((name) => {
let image = document.createElement('img');
image.src = `src/assets/images/${name}.png`;
let newDiv = document.createElement('div');
newDiv.appendChild(image);
document.getElementById('images').appendChild(newDiv);
});
}

This happens because parcel hashes your assets during building. When executing the js, ${name} is not aware of the (parcel) hash and therefore doesn't finds the correct file. Try to take out the assets from the build process and copy them to your dist folder (you'll probably want to automate this at some point). So the assets file names do not get hashed.

Using external JavaScript files in a WinForms/WPF WebBrowser control

I found a cool feature on a website, implemented in JavaScript, I'd like to use it as is in my desktop application (for personal use).
During my experiments I managed to generate custom HTML on the fly, feed it to the browser using webBrowser1.DocumentText = [my generated HTML]
I've managed to put some inline JavaScript into the HTML, and hook it up via a ScriptManager so that I can call the JavaScript from my C# code, pass a value to it, and get a return value.
But the feature I'm trying to use is a bit more complicated: it's no less than 10 JavaScript files. 2 of them are referenced directly in the web page the usual way <script src="/js/script1.js" type="text/javascript"></script>
The other 8 are loaded in one of the scripts:
var elem = document.createElement("script");
elem.type = "text/javascript";
elem.src = "/js/" + filename;
document.body.appendChild(elem);
These 8 files are in fact data files, even though the data is represented in JavaScript. They're pretty large, over 1MB each. Stuffing it all into the HTML file seems quite stupid. Also, the script that loads the data creates a "file map" and further refers to the data based on which file it's in:
var fileMap = [
[/[\u0020-\u00ff]/, 'file1.js'],
[/[\u3000-\u30ff]/, 'file2.js'],
[/[\u4e00-\u5dff]/, 'file3.js'],
...
I don't want to resort to modifying the JavaScript, because it's not exactly my strong point. So the browser needs to "see" the js files in order to be able to use them. I thought of creating the file structure locally, and navigating the browser there. But I don't want any loose files in my solution. I'd like to have everything embedded if possible. And I doubt I can get the browser to navigate to an embedded resource, and see other embedded resources as files. Any idea how I could get around this?
EDIT:
I've tried to do it with local files. No luck. I get the HTML to load properly, but when I try to invoke a JavaScript call, nothing happens. I tried pointing the browser to those js files, to make sure they're there. They are. I tried an element with src attribute pointing to an image in the same subfolder as the script files. It gets rendered. It's as if external js files refuse to load.

I had a similar need as your scenario and I addressed it using two key points embedded in two other Stack Overflow answers. As noted by SLaks' answer here the first key is using the syntax file:/// as the prefix for an absolute path to external files. The second is using .Replace("\\", "/") for an absolute file path as listed in Adam Plocher's answer and one of his follow-up comments here.
In short, the final output for each external file in an HTML page will look something like:
<link href="file:///c:/users/david/myApp/styles/site.css" rel="stylesheet" type="text/css">
or
<script src="file:///c:/users/david/myApp/scripts/JavaScript1.js"></script>
Using the format in the samples above in my HTML file resulted in the WebBrowser control loading external CSS, image or script files.
The details and solving the scenario in the question
In the womd's answer in the first referenced SO answer above he used the method System.IO.File.ReadAllText() to load script files and embedded the text of the script files into the <head> tag. As you indicated in your question loading script files directly into the HTML page is not what you're looking to do.
The solution below involves using the same System.IO.File.ReadAllText() method but loads the text of the HTML page instead. The premise works similar to the Razor View Engine in ASP.NET.
The main idea in the solution below involves adding a temporary string in an HTML page that will be loaded into the WebBrowser control and then replacing this temporary string in a C# method in my app just before the HTML page is set to be loaded into the WebBrowser control.
Here are the basic steps to my solution:
Add a temporary string for each external reference in the HTML file.
Declare a variable for the absolute path in a script tag within the HTML file. This step is not necessary unless you're going to use the absolute path elsewhere within your JavaScript code. Your scenario involves delay loading external script files via JavaScript code so this step was necessary.
Modify the src property in the JavaScript code that delay loads the other script files with the absolute path variable.
Add a method in your app to loads the HTML page file as a text string and then replaces all temporary string instances with an absolute path containing the prefix 'file:///'. The absolute path should have forward slashes.
Set the 'DocumentText' property on the WebBrowser control to the updated HTML.
Set the 'Copy to Output Directory' of each external file in your project to 'Copy always' or 'Copy if newer'. This step may not be necessary if you have a fixed location to your external files and that location is not within the build or publish directory used by Visual Studio.
The following are the details for each step. I added a lot of detail that you can skip. I was verbose to reduce any confusion since the steps make changes to several places in the project.
1. Using a temporary string
I used the string "/ReplaceWithAbsolutePath/" but you can use any distinct text. Each reference to an external file in the HTML page looks like:
<!DOCTYPE html>
<html lang="en" xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="utf-8" />
<title></title>
<link href="/ReplaceWithAbsolutePath/styles/site.css" rel="stylesheet" type="text/css">
<script type="text/javascript">
var absolutePath = "/ReplaceWithAbsolutePath/";
</script>
</head>
<body>
<p>My web page</p>
<script src="/ReplaceWithAbsolutePath/scripts/JavaScript1.js"></script>
</body>
</html>
2. Declare absolute path variable
Note in the above HTML page I listed a <script> tag with the declared variable 'absolutePath' set to the temporary string. (In the HTML page above the variable is added a global variable and that is not necessarily best practice. You can declare the variable within a namespace instead of declaring it in the global namespace.)
3. Modify the delay load script to include absolute path variable
Add the 'absolutePath' variable to your JavaScript file that delay loads other JavaScript files containing your data.
elem.src = absolutePath + "/js/" + filename;
4. C# method to replace all temporary string instances
Within your project add the following line to your form load event handler or place this line somewhere in your initialization of the WebBrowser control.
webBrowser1.DocumentText = GetUpdatedHtmlWithAbsolutePaths("/ReplaceWithAbsolutePath/", "HTMLPage1.html");
Add the following method to your code. Update the call to the method in the line above with the name of the class instance where the following method is placed.
// The result of this method will look like the following example:
// <script src="file:///c:/users/david/documents/myApp/scripts/JavaScript1.js"></script>
public string GetUpdatedHtmlWithAbsolutePaths(string tempPathString, string htmlFilename)
{
// Get the directory as the application
// stackoverflow.com/questions/674857/should-i-use-appdomain-currentdomain-basedirectory-or-system-environment-current
// Note that the 'BaseDirectory' property will return a string with trailing backslashes ('\\')
string appDirectory = AppDomain.CurrentDomain.BaseDirectory;
// Replace '//' with '/' in the appDirectory string
appDirectory = appDirectory.Replace("\\", "/");
// Read all of the HTML text from the HTML page file
string html = System.IO.File.ReadAllText(appDirectory + #"\" + htmlFilename);
// Replace all '/ReplaceWithAbsolutePath/' strings within the HTML text with
// the absolute path on the local machine
html = html.Replace(tempPathString, "file:///" + appDirectory);
return html;
}
5. Set the DocumentText property of the WebBrowser control
I added the initialization of the WebBrowser control in the form load event handler but you can, of course, add the line that sets the DocumentText property wherever you initialize your WebBrowser control.
private void Form1_Load(object sender, EventArgs e)
{
// Set the document text of the web browser control with the updated HTML
webBrowser1.DocumentText = GetUpdatedHtmlWithAbsolutePaths("HTMLPage1.html");
}
6. Set the 'Copy to Output Directory' of each external file
Take a look at the answer posted by Matthew Watson in this Stack Overflow question if you want your external files included in your solution/project file structure.
You can add files to your project and select their properties: "Build
Action" as "Content" and "Copy to output directory" as "Copy Always"
or Copy if Newer (the latter is preferable because otherwise the
project rebuilds fully every time you build it).
Then those files will be copied to your output folder.
This is better than using a post build step because Visual Studio will
know that the files are part of the project. (That affects things like
ClickOnce applications which need to know what files to add to the
clickonce data.)
In short, add the external file to your project. You can add the external to any subfolder in your project. (In Visual Studio 2013 or 2015 -- I don't have VS2012) Right-click on the external file in the Solution Explorer and select Properties from the context menu. The Properties pane will be displayed. In the Properties pane change the setting for 'Copy to Output Directory' to 'Copy always' or 'Copy if newer'.
Use View Source to verify absolute path strings
Run your project and it should load your external files in the WebBrowser control. Assuming you have not set the property wbChartContainer.IsWebBrowserContextMenuEnabled = false; in code or in the Properties pane for WebBrowser control you can right-click on the WebBrowser control when your form is running. Click 'View Source' from the context menu and check the paths to your external resources in the View Source window.

InAngularJs, ng-src for img doesn't show for local files

I have an ng-repeat that, among other thing, outputs on image:
<div class="installation" get-products install-index="{{$index}}" ng-repeat="installation in installations track by $index">
...
<img ng-src="{{installation.logo}}" />
...
</div>
When my app starts it downloads needed images and stores their location in a local database. When the page is viewed the installations are populated:
<div class="installation ng-scope" ng-repeat="installation in installations track by $index" install-index="43" get-products="">
...
<img src="C:/Users/.../AppData/Local/Packages/.../LocalState/installations/.../...png" ng-src="C:/Users/.../AppData/Local/Packages/.../LocalState/installations/.../...png">
...
</div>
(dots used to hide person and client data)
If I paste the src location into my browser I see the image so I know it's saved at that location. However, in my app it's not showing. This is a constant issue through the app with the downloaded files. I know the image are in the correct area and the src location is correct but none of them show.
--- EDIT ---
I do have white listing applied as I was getting an unsafe for file:///. Also, when I was using a relative path it was working fine. I had a preloaded database that pointed to file inside the app files.
I don't think it's an access issue since I have a .db file at the same location that all my data is being pulled from.
--- EDIT ---
I set it as file:///C:/... and I'm having the same issue.
I also tried file:///C:/... , http://localhost/..., http://localhost:/..., http://localhost:C/..., C:/..., and file:///.... None of witch give me anything. The first two localhost items do give me a broken image icon, that's about it. I'm not running a local server, just thought I'd try it.

You can do this in two different ways:
1) Use the file protocol
2) use a local host server to store the picture and access it from the local host
for security reasons you cannot use your file system path for images. you shouldn't even use it at all, because when your app gets hosted, you wouldn't be accessing the image via such paths.
method 1:
just add file:/// in place of the c:/. file is the protocol for your file system, just as http or HTTPS is a web protocol.
NB: I haven't tested or used this before so I'm not really certain. I'm posting this from a small mobile device. but I believe it should work.
method 2:
start your wampserver or python server or any local server you have. put the image in a folder where your server can access (if wampserver, this would be a folder or directory in your WWW). say the name of the folder is "my_images" and your wampserver is running on localhost.. you can access the image like so:
http://localhost/my_images/image_name
use this path for your ng-src.

Because I Cordova File and Windows weren't playing nice using the call for cordova.file.dataDirectory didn't work. Instead I used the fs object returned by window.requestFileSystem(...,function(fs){...});
When generating my save to path as well as the path to create directories and location data I used fs.winpath which returned C:/.... The web (which Cordova basically is) won't allow you to have access to local files not associated with the site/apps structure, which is now obvious.
I dug in to the fs object and found fs.root.nativeURL points to ms-appdata:///local/. Switching everything over to this still downloaded all files and directories to the same location but stored that to the database as the file location. When the app loaded the ms-appdata path instead of the C:/ path the images displayed.

oh, a Cordova app.. why don't you place the file in an images folder In your project. since all files will be loaded using index.html (I assume). you can easily refer to the file relative to the location of index.html. how I would normally organize my project is that, my index.html and folders containing resources like js, CSS etc would be on thesame level, so I can easily get the image files using ng-src="img/image_name". so I could have a structure like this
index.HTML
img
..image_name.ext
..image2.ext
css
..style.css test it in a browser location if it works, it will work on the device. Cordova would know how to translate d into something it can recognise.
This is some sample code, i quickly put together. I tested it and it worked. Firstly i create a directory using file plugin and then download to this directory using file transfer. Replace the url parameter of file transfer with the url you wish to download from.
$ionicPlatform.ready(function() {
$cordovaFile.createDir(cordova.file.externalDataDirectory,
file_location,false).then(
function(success){
return success;
},function(error){
return error;
}).then(function(value){
var url = material.file_uri;
var targetPath = cordova.file.externalDataDirectory
+ "/" +file_location + "/" + file_name;
var trustHosts = true
var options = {};
$cordovaFileTransfer.download(url, targetPath, options, trustHosts)
.then(function(result) {
console.log(result)
}, function(err) {
console.log(err)
}, function (progress) {
$timeout(function () {
console.log(Math.floor((progress.loaded / progress.total) * 100));
})
});
})
})

MVC5 and Javascript relative image paths confusion

My mvc5 webApp can´t seem to display images if I run it on the virtual server, however if I run it locally it works.
So I have tried several approaches and none that allowed me to run the app on the virtual server or on my pc worked I have tried:
(these worked if I was running this locally)
Images/arrow.png
/Images/arrow.png
This path works for the virtual server but not locally.
webAPP/Images/arrow.png
I know about #Url.Action but I have a lot of different images, around 15, and I don´t know if using #Url.Action is a good idea for that many.
any small example would help tremendously!

If you know the path to the images from the site root you can do the following in MVC:
#Url.Content("~/images/my-image.jpg")
The "~/" will map from the site root.
EDIT:
If you're working within a JS file and struggling with relative paths maybe you could add a 'basepath' variable to the top of the file and work with that:
var basePath = "http://www.mywebsite.com/images";
Then in your code, your image URL returned would be something like:
var imgUrl = basePath + "/my-image.jpg";

try this:
#Url.Content("~/Images/arrow.png")

javascript file not loading

Trying to import my js file from my page.
My page is in webcontent/mydomain/templates/page.xhtml
My js is in webcontent/mydomain/test/scripts
In page.xhtml
<script type="text/javascript" src="../test/scripts/test.js"></script>
But still the script is not getting picked.
Can anyone tell how I need to give the path in src.

Try this:
<script src="/test/scripts/test.js"></script>

Provided that webcontent is the root of public web content and thus /mydomain is also a public folder and thus your JavaScript is standalone available by http://localhost:8080/context/mydomain/test/scripts/test.js, assuming a domain of http://localhost:8080 and a context path of /context, then the following should do:
<script src="#{request.contextPath}/mydomain/test/scripts/test.js"></script>
This will generate a domain-relative URL with a dynamically inlined context path, which is much more robust than fiddling with ../ which would make the URI relative to the current request URI (as you see in browser's address bar) and not to the physical location of the template file as many starters incorrectly assume.