Call methods in other HTML page - javascript

I am relatively new to web programming (just started html, javascript, php). I wanted to create a database manager for a website I am building. Now, in ios I would create a .h file called DBManager, with a list og methods I can call, and then import this file in any other .m file and do something like:
[DBManager uploadInage: image with completition...];
How can I do this for the web?

There is not a direct equivalent in the languages you mention.
HTML is a markup language and as such does not have funcitons at all.
Javascript and PHP are both interpreted languages, which can be used inline in your HTML. You will find that they aren't as structured in some ways as compiled languages like Objective-C. You can use different approaches to structuring your code, but there is no compiler enforcing them.
So for example, you can deploy some Javascript with your HTML which makes a method call, and it doesn't matter if that method was even written yet. As long as it can be found at runtime, it will work.
The same goes for PHP. Nothing will prevent you from writing and deploying your code making any method calls you like. As long as those methods can be found in some file that's included when the script runs, the code will work.
include() and require() are the commands used to pull in other .php scripts which contain the classes or functions you need. You could write a "header" script which includes all of your dependencies if you like to structure things that way. There are also dependency management tools like Composer - but these are entirely optional.

I don't think its safe (and even possible? Nah, I'm pretty sure it isn't possible ;) ) to directly communicate with a database from HTML / JavaScript / ... .
Objective - C is a language that has a good MVC pattern. (Model / View / Controller). HTML is a markup - language (VIEW - only). You can call a webservice from this view, (With the aid of AJAX or other..), and that webservice can communicate with a database, and provide you the needed information. ==> Anyhow, there is a need to create a webservice here!
You can also integrate everything in a Web-application. You can build a webapp on (I like Java, others like .NET, and there are many more...). This is an application that (just like Objective-C) uses an MVC pattern. The HTML page acts as the view, (Storyboard in XCode), you have a controller that builds and fills/returns the view to the user, (just as the ViewControllers).
You should look at both options, depending at what you want to do, both choices work.
I'm happy to help you with further questions or remarks.

Related

How to not duplicate files for each language on a multilingual website

I'm currently working on a website that it meant to be translated in multiple languages. I've did a lot of research but I might have missed something because I really don't get ho my structure should be organised.
To put some context in, my website is developed using html, css, js + jquery, has a MySQL database and use a Java EE backend as a rest API to fetch data from the database.
I would like the urls to look like this (as suggested on a lot of websites) :
www.example.com/fr/page1
www.example.com/en/page1
But does it means my file directory should look like this?
index.html
fr/
----index.html
----page1.html
----page2.html
en/
----index.html
----page1.html
----page2.html
js/
----page1.js
----page2.js
If so, then I need to copy my index.html (and every other page) in every single language directory. This seems very bad since every time I will have to change something in the code, I will have to change it in every single files...
What I would love to have is just one copy of each files (index.html, page1.html, etc) then a file containing all translations for each language and then use these files to populate the html template.
The structure being something like this :
index.html
page1.html
page2.html
language/
----fr.json
----en.json
js/
----page1.js
----page2.js
Something simple like that. In this example I would only have a copy of each files but then how to work with the url to still make it like www.example.com/fr/page1 even though there isn't such directories?
I don't know if all of this makes sense, I'm pretty new to this and I'm really lost with this multilingual website problem... I would like to make it the cleanest way possible to be able to expand it to other languages later really easily.

How can I access embedded ASP.NET GlobalResources in JavaScript?

I'm working on a legacy ASP.NET project, which I'm trying to massage into shape slowly, but I can't make significant changes without it all collapsing like a chocolate finger house....
I've tried to find a solution for this, but failed miserably due to the specific mix of terminology ("javascript", "embedded" and/or "resource" just give me information as to how to embed a .js file...), and the fact that it's probably a weird way of doing things.
The project makes use of App_GlobalResources for translatable strings, which is used in C# code behind, the markup and in some of the JavaScript. For example:
HTML:
Text="<%$Resources: Resources, MeasuresLabel %>"
JS:
setDialogTitle('summaryDialog', physicalElementName, Resources.Resources.Summary);
This was all working fine, until we started using NUnit for some integration testing. To make the Resources.resx available to NUnit I've followed Scott Allen's suggestion, which works for NUnit but means that the above Resources.Resources is undefined.
So, my question is with this embedded file, how can I make it accessible to the JavaScript (or is there a better way I can make it available to NUnit)?
There's an the added complication due to the code I want to access it with being in separate .js files, rather than within script tags in the .aspx files.
EDIT
After looking at it some more, the real challenge is the properties that are accessed in the JS are static. Due to the number of places these are referenced, it's not practical to add a variable for each string that's being used.
I think that JS files aren't going through the ASP.NET engine and they are served as they are, that's why Resources.Resources.Summary isn't defined in your case, while it will work when embedded inside <script> tag in .aspx file.
The only way I know around this would be to store the used resource values in global javascript variables on the .aspx page and then use them in loaded JS files.

Displaying java variable on html page

I really did not want to be posting this, but here I am. It looks like I have been unable to find any way to simply display a java variable in an html doc. I have a feeling this isn't possible and I should be using javascript or something else but I would love it if someone could point me in the right direction.
My Java code is simple and basically just creates a single int that I would like to use in my html doc. For arguments sake let's imagine this:
JAVA CODE
public class Counter {
public static void main(String[] args) {
int number = 24;
}
}
Once again for argument sake
HTML CODE
<HEAD>
<script src="java/counter.java"></script>
</HEAD>
I've looked into things like document.write() and Element.innerHTML but I believe these things are probably associated with Javascript and/or JSP. I'm expecting more of an explanation rather than some simple code since I'm sure I'm going about this wrong. Just want to know how I should create my "counter", whether it be in Javascript or something else. I am using PHP and CSS so I also am also not sure if I should be using those to access my programs final int. First dive in to multi language programming so be gentle. Thanks!
you have to write your variable like this
"<%= variable name here %>"
in your JSP file
The first thing i have to mention is "YOU CANNOT DO IT WITHOUT AN APPLET OR JAVA WEB SERVER" with live updates of your variable.
If you don't want to live update your web page, you can create a .html file with java and open it through your browser.
If you are free to use another programming option you can use javascript instead of java.
If you need both live update of variable and java as programming language, you should use one of java applets and jsp page with server. I recommend to use jsp since it is highly available of resources.
First of all, lets clear smth here. Java is an interpreting language, which means you cannot run java without calling its executable interpreter or a web container or application deployment platform.
If you run java code, very firstly you should compile it and get compiled byte code. This would be a ".class" file. Then if you want to run it as standalone application then you should use platform dependent interpreter. For Windows OS, it is "java.exe", for linux platforms it would be "java" executable. For WEB applications there are some sort of containers like Jetty, Tomcat which can run class files and compile (JSP files not java).
Lets assume that, you are using Tomcat with your web application. Then with your app, you can run your code with JSP file or with async call it is difficult in your case.
Find a very simple JSP tutorial and try howto run your code.

Very large single page application design problems

I am currently writing whats going to be a very, very large single page web/javascript application.
Technologies I am using are ASP.NET MVC4, jquery, knockout.js and amplify.js.
The problem I am having is that most if not all of the single page application examples are for smaller applications where having all of the script templates (be it jquery, handlbars, etc...) are all in the same file along with the rest of the html code. This is fine for smaller apps but the application I am building is an entire maintenance logistics application with many, many, many screens.
The approach I took so far is I have an outer shell (my main index.cshtml file) and I am using jquery's load() method to load or rather inject the particular file I need when a user makes a certain selection.
example:
function handleLoginClick(){
App.mainContentContainer.delegate('#btnLogin', 'click', function() {
App.loadModule('Home/ProductionControlMenu', App.MainMenuView.render());
});
}
here's the code for the App.loadModule function:
App.loadModule = function(path, callback){
App.mainContentContainer.load(App.siteRoot + path, callback);
};
All was going well until I needed to actually start interacting with the various form elements on the newly loaded screen. jquery can't seem to get a handle on them directly. I can't use .live() or .delegate() because they aren't events, they are textboxes and buttons and sometimes I need to change their css classes.
They only way I found is to get a handle on an element from the outer shell (something that wasn't loaded via .load() ) and use jquery's .find() method like so:
App.mainContentContainer.find('#btnLogin').addClass('disabled');
clearly I don't want to have to do something like this everytime I need to interact with or even retrieve values from a form element.
Does anybody have any ideas as to how I can create a maintainable very large single page application with potentially hundreds of .html files without having to have all that html code located in a single file and still get around this .load() issue I am having?
Any thoughts would be greatly appreciated. :-)
V/R
Chris
UPDATE
I thought I'd post an update and as to how things went and what worked. After much research I decided to go with Google's AngularJS Javascript framework. It simplified the ordeal exponentially and I would definitely, definitely advise all who are looking into making a large SPA to give it a look.
Links:
Main Site
http://angularjs.org/
Awesome free short videos on Angular:
http://www.egghead.io/
This is actually a very complicated question as it really gets down to the design of your architecture.
For large-scale single-page applications, it's best to use some sort of front-end MV* style framework such as backbone.js, which ties in to jQuery quite usefully. You should also think about using some sort of dependency management framework such as require.js in order to load your scripts and dependencies asynchronously, and even better -- use the AMD pattern in your application design to make your architecture modular and easier to manage.
As far as how this relates to your MVC4 project, you have some options:
Do you want to use MVC as a "service layer" of sorts, that simply returns JSON objects, allowing your front-end to do the markup/template creation (think handlebars.js), or
Do you want your MVC project to return partial views (HTML) as a response, where you leverage the Razor templating system and simply use the front end to display what comes back from the server?
Either way, you will have to devise a way to handle front-end events and navigation (backbone provides both of these things when coupled with jQuery). Even more complicated is the pattern you choose to notify one view of another view's activities (there are many ways to do this) -- a publish/subscribe pattern for example.
I hope I have helped a bit, I know I'm not fully answering the question, but the answer could get really long!
Lots of things are wrong with your approach. What I'd recommend is to watch some presentations on how people build Single Page Applications and what tooling is mostly used.
This seems like something reasonable: http://singlepageappbook.com/
You will at least want
some kind of modules system (I recommend AMD – http://requirejs.org)
an MV* framework (Backbone, Ember.js etc.)
DOM/AJAX Framework (jQuery, Mootools etc.). Some frameworks offer this and all of the above (Dojo, YUI, Sencha)
build solution (to have different environment in development / production)
Couple of good links:
http://nerds.airbnb.com/slides-and-video-from-spike-brehms-tech-talk
http://video.copenhagenjs.dk/video/3413395/simon-hjberg-swipely-building
http://backstage.soundcloud.com/2012/06/building-the-next-soundcloud/
http://www.youtube.com/watch?v=vXjVFPosQHw
If you don't need a complicated truly SOFEA Single Page App then I recommend you go the PJAX route.
Then you just write your app as a normal web 1.0 app with the performance benefits of a single page load. I urge you to consider this an option as it allows you to do most of your validation work server side.
The idea is very simple on every response your sending the whole page back minus the header and footer (which contains the javascript and css includes). DOM rendering time is incredible fast these days... whats not is a full page reload, So don't worry about the size of the HTML your returning back.
Also the "PJAX way" is much easier to cache, Google SEO friendly and is in fact what the new Basecamp does.
Note: Wanted this to be a comment not an answer but don't have enough exp to post comments ;(
[any corrections by community members welcome!]
Important points to consider for single page apps:
Lazy loading is vital as you don't want hundreds of js files loaded straight away as user first loads the page (very slow load time).
Good File organisation,- helps making changes easier, reduces complexity a bit and promotes reusable components. Makes testing of components easier.
Testing,- Since single page apps have a lot of javascript going on under the hood you would need a test framework for automatically testing components. This testing is on top of the tests you would use to confirm if certain user controls are rendered etc as you wouldn't want a viewless component making an ajax call to server when it shouldn't etc.
+1 for gryzzly's point about using a framework.
Sencha have a nice MVC like framework for their ExtJs product. They have data stores, ajax, lazy loading, class hierarchies and a lot more all bundled into the package. They have a good api page also to lookup object properties and methods (handy since there doesn't seem to be any intellisense for javascript :/ ). Their api page is; as far as I know, an example of a single page app. I know much of the stuff ExtJs does you can find an open source alternative but I like that it's just the one library and I don't have to download a couple of different frameworks to do various operations. [note: I have no affiliation to Sencha except for being a customer of theirs and like their stuff.]
Conclusion:
I'd say it would be quite difficult to manage a large single page app without using some client side framework; whether open source or not, and without using some architectural pattern like a client side MVC.
Single page apps I think are more complicated so your team would need to be quite handy at understanding the concept of a single page app and how to implement it. If you pull it off the site will be amazing in terms of user experience.
I would recommend to use Sammy.js and split various viewmodels in knockout to a separate url. And if you're using asp.net mvc 4, use partial views (user controls) so that you put all code in one file. And name all and split all js-code in a meaningful way, filename and namespace in js. That will help a lot in maintainability and your own sanity in the long run.
And use common sense!
The way I did it was to include javascript code related to the template along with the template itself. And then load the whole template+script thing using ajax. If you want to try this be warned that most browsers don't execute <script> tags injected into the page. Especially if done using innerHTML. As such you should eval the script tags yourself (alternatively you can use document.createElement to inject the script but this does not offer any additional advantages compared to eval since the browser will blindly execute the script anyway).
In my case, to make it easier to grab the html and script portions of the template I store my templates in XML files instead of plain old HTML. That way I can simply use .responseXML of the ajax request to parse the template. My template has the following basic structure:
<template options...>
<title>Optional</title>
<html><![CDATA[
Template body
]]></html>
<init><![CDATA[
// code that only needs to execute once
]]></init>
<script><![CDATA[
// code that needs to run every time
// the template loads
]]></script>
</template>
You also need to remember to configure your server to reply with the correct content type for you templates. Otherwise resultXML won't work. This is not the only way to implement this system of course. You could simply save your templates as HTML and then parse that HTML to extract scripts to execute.
The main bulk of your code, the functions, constructors, objects etc. can be included in a js file. The template script only need to call those functions to tell the rest of the page how to work with the template.
If you further separate your data from your template and only populate the template with data on the page or make a separate ajax request for JSON data then you can configure your server to make the browser cache your templates. This is especially useful for often used templates (such as templates for dialog boxes). This allows the browser to download the template only once and use the cached version the next time you call the template.
Anyway, that's how I did it last time. It scaled well enough to serve facebook users (the web app was a facebook app). Just sharing my experience. Hope it helps.
I've written a few huge single page application using Dojo Toolkit. I'm pretty sure whatever JavaScript framework you choose will probably work for you. I use Dojo because it provides me with features that makes huge single page application development easier to manage.
You can use Dojo's widget system to help you define all your screens and forms as widgets and then when you need them you can just instantiate and insert them wherever you need it. When ever you want to get rid of it, you can simply call destroy or destroyRecursive on that particular widget and its gone. Dojo's widget system also help you separate your HTML from your JavaScript, but still keep it together so that they are not located all over the place.
I've include a simple widget definition for a Login form.
This is the HTML template.
/* mine/forms/Login.html */
<div>
${form_name}
<label>Username</label>
<input data-dojo-type="dijit.form.TextBox"
data-dojo-attach-point="_usrfld" />
<br />
<label>Password</label>
<input data-dojo-type="dijit.form.TextBox"
data-dojo-props="type: 'password'"
data-dojo-attach-point="_pwdfld" />
<br />
<input data-dojo-type="dijit.form.Button"
data-dojo-props="label: 'Login'"
data-dojo-attach-event="onClick:_handleLogin" />
</div>
This is the JavaScript portion for the widget.
/* mine/forms/Login.js */
define([
"dojo/_base/declare",
"dijit/_Widget",
"dijit/_Templated",
"dijit/_WidgetsInTemplateMixin",
"dijit/form/Button",
"dijit/form/TextBox",
"dojo/text!./Login.html"
], function(
declare,
_Widget,
_Templated,
_WidgetsInTemplateMixin,
Button,
TextBox,
template
) {
return declare("mine.forms.Login", [_Widget, _Templated, _WidgetsInTemplateMixin], {
// assign the template
templateString: template,
// signal that we will have widgets within our template and the parser should
// locate them and instantiate them
widgetsInTemplate: true,
form_name: "My Login Form",
// place holders that will be referencing the corresponding widgets
// that I have placed a data-dojo-attach-point on
_usrfld: null,
_pwdfld: null,
_lgbtn: null,
// a call back function that will be trigger when the Login button is clicked
_handleLogin: function() {
var usr = this._usrfld.get('value');
var pwd = this._pwdfld.get('value');
// now you have the username & password
// you can use it to login
}
});
});
There are a few benefits that the widget system provides:
The HTML template will be loaded for you when needed
You can have widgets within widgets. Dojo takes care of instantiating and even destroying those widgets for you
You can use dojo's simple template language to help with inserting strings. The example above uses ${form_name}. If you want to use a more sophisticate facility dojo also supports a Django similar syntax templating language. This will allow you to use most of the tags available with Django like for, if-then-else, etc.
data-dojo-attach-point is very helpful. If you use this, you will never need to assign id to a DOM element anymore. You will not need to locate the element in your HTML DOM tree. The variable you name in data-dojo-attach-point will be auto assign to reference the widget or DOM element you have defined in your template. The example above uses the _usrfld, _pwdfld, and _lgbtn.
data-dojo-attach-event is also very helpful. If you use this, you will not have to manully add an event hook to the button, Dojo's widget system will hook it for you and will also clear the hook when your widget is destroyed.
If you use Dojo's build system, which is a system that takes all your JavaScript codes and compresses them, Dojo will replace your template with the actual HTML so that when you load your widget in production mode, Dojo doesn't have to make another AJAX request to grab your template.
These are just some of the features I use daily when I develop my projects. Hopefully it will provide you with some insight that you can use to make your decision when choosing the proper JavaScript framework for your project. As a side note, I'm not advocating Dojo or anything, just wanted to share what works for me.
To handle large size single page application it's recommended to break the individual module into different apps.
example : apps like search page app and result page app.

Web crawler: Using Perl's MozRepl module to deal with Javascript

I am trying to save a couple of web pages by using a web crawler. Usually I prefer doing it with perl's WWW::Mechanize modul. However, as far as I can tell, the site I am trying to crawl has many javascripts on it which seem to be hard to avoid. Therefore I looked into the following perl modules
WWW::Mechanize::Firefox
MozRepl
MozRepl::RemoteObject
The Firefox MozRepl extension itself works perfectly. I can use the terminal for navigating the web site just the way it is shown in the developer's tutorial - in theory. However, I have no idea about javascript and therefore am having a hard time using the moduls properly.
So here is the source i like to start from: Morgan Stanley
For a couple of listed firms beneath 'Companies - as of 10/14/2011' I like to save their respective pages. E.g. clicking on the first listed company (i.e. '1-800-Flowers.com, Inc') a javascript function gets called with two arguments -> dtxt('FLWS.O','2011-10-14'), which produces the desired new page. The page I now like to save locally.
With perl's MozRepl module I thought about something like this:
use strict;
use warnings;
use MozRepl;
my $repl = MozRepl->new;
$repl->setup;
$repl->execute('window.open("http://www.morganstanley.com/eqr/disclosures/webapp/coverage")');
$repl->repl_enter({ source => "content" });
$repl->execute('dtxt("FLWS.O", "2011-10-14")');
Now I like to save the produced HTML page.
So again, the desired code I like to produce should visit for a couple of firms their HTML site and simply save the web page. (Here are e.g. three firms: MMM.N, FLWS.O, SSRX.O)
Is it correct, that I cannot go around the page's javascript functions and therefore cannot use WWW::Mechanize?
Following question 1, are the mentioned perl modules a plausible approach to take?
And finally, if you say the first two questions can be anwsered with yes, it would be really nice if you can help me out with the actual coding. E.g. in the above code, the essential part which is missing is a 'save'-command. (Maybe using Firefox's saveDocument function?)
The web works via HTTP requests and responses.
If you can discover the proper request to send, then you will get the proper response.
If the target site uses JS to form the request, then you can either execute the JS,
or analyse what it does so that you can do the same in the language that you are using.
An even easier approach is to use a tool that will capture the resulting request for you, whether the request is created by JS or not, then you can craft your scraping code
to create the request that you want.
The "Web Scraping Proxy" from AT&T is such a tool.
You set it up, then navigate the website as normal to get to the page you want to scrape,
and the WSP will log all requests and responses for you.
It logs them in the form of Perl code, which you can then modify to suit your needs.

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