Using eval also opens the door to bugs, hacks and security issues. Like Dynamic Imports you can load one or many scripts with a fetch call using promises to control order of execution for script dependencies using the Fetch Inject library:.
The jQuery library provides loading functionality in one line :. To avoid the overhead of jQuery, this is an ideal solution. The script can even reside on a different server. Furthermore, the browser evaluates the code.
Now, there is a big issue you must know about. Doing that implies that you remotely load the code. Modern web browsers will load the file and keep executing your current script because they load everything asynchronously to improve performance.
This applies to both the jQuery method and the manual dynamic script loading method. It means that if you use these tricks directly, you won't be able to use your newly loaded code the next line after you asked it to be loaded , because it will be still loading. Well, you can use the hack the author suggests in the link I gave you.
In summary, for people in a hurry, he uses an event to run a callback function when the script is loaded. So you can put all the code using the remote library in the callback function. For example:. Note that the script may execute after the DOM has loaded, or before, depending on the browser and whether you included the line script.
There's a great article on Javascript loading in general which discusses this. If anyone is looking for something more advanced, try out RequireJS. You'll get added benefits such as dependency management, better concurrency, and avoid duplication that is, retrieving a script more than once. You can write your JavaScript files in "modules" and then reference them as dependencies in other scripts.
Or you can use RequireJS as a simple "go get this script" solution. RequireJS loads plain JavaScript files as well as more defined modules. It is optimized for in-browser use, including in a Web Worker, but it can be used in other JavaScript environments, like Rhino and Node. It can be used simply to load existing JavaScript files, so you can add it to your existing project without having to re-write your JavaScript files.
There actually is a way to load a JavaScript file not asynchronously, so you could use the functions included in your newly loaded file right after loading it, and I think it works in all browsers.
You need to use jQuery. However, this method also has a problem: if an error happens in the imported JavaScript file, Firebug and also Firefox Error Console and Chrome Developer Tools as well will report its place incorrectly, which is a big problem if you use Firebug to track JavaScript errors down a lot I do.
Firebug simply doesn't know about the newly loaded file for some reason, so if an error occurs in that file, it reports that it occurred in your main HTML file, and you will have trouble finding out the real reason for the error. I also made a simple test for this at Example. It includes a main. And right after including included.
Which is also how Node. This will load targeted JavaScript file. There is a good news for you. Very soon you will be able to load JavaScript code easily. It will become a standard way of importing modules of JavaScript code and will be part of core JavaScript itself. You simply have to write import cond from 'cond.
So you don't have to rely upon any JavaScript framework nor do you have to explicitly make Ajax calls. Static module resolution. Module loaders. Note that to get this working cross-domain, the server will need to set allow-origin header in its response.
The reason why we look for the first script element instead of head or body is because some browsers don't create one if missing, but we're guaranteed to have a script element - this one. You can also assemble your scripts using PHP :. Most of solutions shown here imply dynamical loading. I was searching instead for a compiler which assemble all the depended files into a single output file.
Since I didn't find anything decent of this sort, I wrote a simple tool solving the issue. On the jQuery master branch, they simply concatenate atomic source files into a single one starting with intro. That doesn't suits me as it provides no flexibility on the source code design. Check out how it works with jsic:. For instance:. You just need to be careful when you are including scripts in an HTML file.
The order should be as in below:. I use Sprockets I don't know if there are others. You build your JavaScript code in separate files and include comments that are processed by the Sprockets engine as includes. For development you can include files sequentially, then for production to merge them I had to use a variable myVar1 defined in one JavaScript file myvariables.
As you saw, I had use a variable in one JavaScript file in another JavaScript file, but I didn't need to include one in another. I just needed to ensure that the first JavaScript file loaded before the second JavaScript file, and, the first JavaScript file's variables are accessible in the second JavaScript file, automatically.
The import syntax for achieving CSS-like JavaScript importing is possible using a tool such as Mixture via their special. I assume the application does this via one of above-mentioned methods. Mix files are simply. A mix file simply extends the functionality of a normal style or script file and allows you to import and combine.
Mixture outputs this as scripts-global. Note: I'm not in any way affiliated with Mixture, other than using it as a front-end development tool. I came across this question upon seeing a. Then I realized that it was an application-specific file type somewhat disappointing, agreed. Nevertheless, figured the knowledge might be helpful for others.
You can define a start script in your package. Run npm run to see available scripts. JavaScript versions are not mentioned here. View all posts by publicaffairs Website. Activate JavaScript in Google Chrome. Open Chrome on your computer. Click Privacy and security. Click Site settings. Click JavaScript. Turn on Allowed recommended. How run js file in shell script? How to run JavaScript in Terminal. How is JavaScript run? How do I run JavaScript on Windows? To try it:. Open the Console. The Console immediately displays the result 4 on the next line while you type.
The Eager evaluation feature helps you write valid JavaScript. How do I run JavaScript on a website? How do I open a. JS file? How do I run JavaScript in Termux? Follow these steps to run TypeScript in Termux. Install Termux app from Play Store. Install Node. Install TypeScript node module on Termux using command npm install typescript. Install code editor like Micro using command pkg install micro. How do I run a node js file?
React Native. Python Design Patterns. Python Pillow. Python Turtle. Verbal Ability. Interview Questions. Company Questions. Artificial Intelligence. Cloud Computing. Data Science. Angular 7. Machine Learning. Data Structures.
Operating System. Computer Network. Compiler Design. Computer Organization. Discrete Mathematics.
0コメント