Here is an interesting problem regarding the IncludeEventHandler.
I am developing a Spring-Based application which uses velocity which has different VENDORS having a separate portfolio site. I am letting vendors customize the pages by providing them the Velocity templates which are being stored the database and are picked up by the velocity engine using a DataSourceResourceLoader.
My table is organized like this.
The vendors may parse other templates by calling the macro #parse and passing their vendorid/template-name so that it looks like this.
#parse("20160109144/common-css.vm")
Now the actual problem is picking up the template according to vendorid.
I have a class (extending IncludeEventHandler) which overrides the includeEvent method. Now what can I do to return the desired template? I dont want to change the names and make them look like 20160109144/home.vm
With OP's question, the intent was to provide an alternate behavior to the DataSourceResourceLoader.
Unfortunately, the Velocity Engine version 1.7 doesn't have ability to change the SQL statement that is used to retrieve the template.
The DataSourceResourceLoader extends the ResourceLoader abstract class. That said, if you reference the source, you should be able to implement a custom ResourceLoader that behaves the way you want it to.
One option, glom most of the code from DataSourceResourceLoader and change the way it determines the template content to load from the database.
I would dump all of the query related material as you will be determining the specific columns you want to load for content. The DataSourceResourceLoader essentially maps the name of a template to a database entry and your implementation essentially revolves around the rules you've defined above.
Hopefully that can provide enough assistance to move forward. I would recommend pulling this in a debugger as well and determine what is and is-not passed in to the related load methods.
Related
I've been using Ruby Selenium-Webdriver for one of the automation scripts I'm developing and I'm being asked to use Page Objects, we use page objects a lot however for this application I am using CSV file instead, I have defined all the xpaths that I'm using in my application in a CSV file and I'm parsing that CSV file in my script to refer to those objects, I would like to know is there much of a difference in using a class for defining Page Objects or using a CSV file instead apart from performance concern? I believe using a CSV file will be an addon for us from configuration standpoint and will make it much easier to maintain, any suggestions on this?
Edit - In our use case, we're actually automating applications built on a cloud based tool, so basically all the applications share same design structure from HTML standpoint so we define xpath patterns in CSV and then we pass certain parameters to some custom methods that we've developed to generate xpath's automatically using the CSV instead of finding those manually as its overhead for us because we already know that all the applications will share similar xpath pattern for all elements.
Thanks
I think, POM is better than CSV approach. In POM, you put elements for a page in a separate class file. So, if any change is to make then it's easier to find where to change/maintain. Moreover, it won't get too messy as CSV file and you don't need to use extra utility function to parse those.
There is also a pageobjects gem that provides a set of libraries over and above webdriver/watir, simplifying the code.
Plus, why xpaths? Its one of the last recommended ways to identify an element.
As for the frameork aspect, csv should be more of a maintenance problem than PageObjects. Its the basic difference between text and code. You enforce Object oriented approach on your elements in PageObjects but that is not possible with csv.
In the best case scenario, you have created a column/separate sheets defining which page that element xpath belongs to. That sounds like an overhead. As your application / suite grows there can be thousands of elements. Imagine parsing/ manually updating a csv with that kind of data.
Instead in PageObjects, your elements will be restricted to the Page. Any changes to the app will also specify which elements may get impacted. Now, when define your element as an object in PageObject, rather than css, you also dont need to explicitly create your elements by reading the csv.
It completely depends on the application and the type of test you might perform.
Since it is an automated test script, you do not have to really worry about the performance of the script (it might take few more milli seconds to parse, which should be OK).
Maintaining all the elements identification properties & corresponding actions in a CSV file will make the maintenance easier and make the framework application independent which are nice. But maintaining your framework is bit difficult to make it more robust. Both approaches have its own pros and cons.
Refer to below posts [examples are in java - but you will get the idea]:
Keyword driven framework
Advanced Page Objects
Update:
If you like both, you can comeup with your implementation to easily integrate these too.
#ObjectRepository(src="/login.csv")
public class LoginPage{
private Map<String, WebElement> elements;
public void login(){
elements.get("username").sendKeys('');
elements.get("password").sendKeys('');
elements.get("signin").click();
}
}
Ie, define all the elements in a config file like csv/json etc. Let the page object refer to the class for the page elements. All the methods will be part of the page class.
I have this idea of generating an array of user-links that will depend on user-roles.
The user can be a student or an admin.
What I have in mind is use a foreach loop to generate a list of links that is only available for certain users.
My problem is, I created a helper class called Navigation, but I am so certain that I MUST NOT hard-code the links in there, instead I want that helper class to just read an object sent from somewhere, and then will return the desired navigation array to a page.
Follow up questions, where do you think should i keep the links that will only be available for students, for admins. Should i just keep them in a text-file?
or if it is possible to create a controller that passes an array of links, for example
a method in nav_controller class -> studentLinks(){} that will send an array of links to the helper class, the the helper class will then send it to the view..
Sorry if I'm quite crazy at explaining. Do you have any related resources?
From your description it seems that you are building some education-related system. It would make sense to create implementation in such way, that you can later expand the project. Seems reasonable to expect addition of "lectors" as a role later.
Then again .. I am not sure how extensive your knowledge about MVC design pattern is.
That said, in this situation I would consider two ways to solve this:
View requests current user's status from model layer and, based on the response, requests additional data. Then view uses either admin or user templates and creates the response.
You can either hardcode the specific navigation items in the templates, from which you build the response, or the lit of available navigation items can be a part of the additional information that you requested from model layer.
The downside for this method is, that every time you need, when you need to add another group, you will have to rewrite some (if not all) view classes.
Wrap the structures from model layer in a containment object (the basis of implementation available in this post), which would let you restrict, what data is returned.
When using this approach, the views aways request all the available information from model layer, but some of it will return null, in which case the template would not be applied. To implement this, the list of available navigation items would have to be provided by model layer.
P.S. As you might have noticed from this description, view is not a template and model is not a class.
It really depends on what you're already using and the scale of your project. If you're using a db - stick it there. If you're using xml/json/yaml/whatever - store it in a file with corresponding format. If you have neither - hardcode it. What I mean - avoid using multiple technologies to store data. Also, if the links won't be updated frequently and the users won't be able to customize them I'd hardcode them. There's no point in creating something very complex for the sake of dynamics if the app will be mostly static.
Note that this question doesn't quite fit in stackoverflow. programmers.stackexchange.com would probably be a better fit
I want to offer a tumblr-like functionality where you can select a template, and optionally customize the HTML of your template in the browser and save it.
Current stack: Mongo, Sinatra (for REST API) for prototype. Will likely be moving to a compiled, statically-typed language later.
Wondering how best to accomplish this. Options I've considered:
Store the HTML in mongo, and duplicate it for all user accounts. So the HTML for the template you choose gets written into your account. Obvious cons of space inefficiency and need to update all users that use that template (if un-customized - you customize it it becomes your own and I won't ever touch it) if the template changes.
Store the templates in templates collection, and put custom templates either into this same collection or into the user collection with the owner of the template. User references a template id. This is quite clearly better than 1 I believe. Especially because I won't need to pull the template every time the user object is pulled.
Some third party library? Open to suggestions here.
File system.
I will need to package up these templates (insert js and stuff the user shouldn't be exposed to) and then serve them. Any advice on how best to approach this is greatly appreciated.
Your approach will depend on how often you foresee people customizing the template versus just going with a standard. How about a hybrid approach?
That is, have a field in the user document that is created lazily (on use) that either stores the custom template, or maybe a diff from one of the standards (not sure about the level of customization you are planning to allow).
Then you can have the template field you describe in 2 above, with a "special" setting for custom templates. While you still have the concern about pulling a template each time, you do have the advantage of knowing that these are some of your more dedicated users - saving a trip to the DB might be advantageous, or you might not care.
If you don't care about 2 trips to the DB for every user, then you take approach 2, add the custom templates to the templates collection and simply reference the new ID for each user that customizes.
It's a balancing act - is the extra data overhead in terms of pulling the template each time worth saving a round trip to the DB or do you want efficiency in terms of the data you get each time at the cost of multiple queries to the DB - only you can answer that one based on how you design your app and how people use it.
For the linked approach you might want to take a look at Database References and Schema Design in the MongoDB docs.
In an upcoming project, we will be creating forms for citizen's to fill out to start the process of applying for the requested license or permit. As one can imagine, a form tends to change often. I would prefer to plan this into the application to avoid making changes on a yearly/monthly/"the big boss want's it yesterday" basis.
My searching has shown me some examples based on the object passed to the view, but those would require coding changes. Others use XML, but never seems to go through the entire process from creating the from to storing the inputted data into the database. It isn't that I need hand holding the entire way; it's that this is something completely different for me and I want some guidance to get me in the right direction. I am thinking along the lines of how these survey sites (like SurveyMonkey) create dynamic polls.
Is there any tools, utilities, tutorials, or books that may cover this quite well?
I would imagine you would probably want to take advantage of Display / EditorTemplates. You would define an interface IQuestion or something, and then have a bunch of different form options that implement that interface. So your model would have a List<IQuestion>, and then for each question in the list, Html.EditorFor(item) or so.
Then some kind of standardized way of storing the answers into a table (perhaps a unique save / load method on IQuestion. That's my take anyways. You could define the questions via DB and then your models could have varying counts (and elements) in the List<IQuestion>. Just run a DB script (or some kind of admin page) and you could dynamically change the form displayed.
After developing in CodeIgniter for awhile, I find it difficult to make decisions when to create a custom library and when to create a custom helper.
I do understand that both allow having business logic in it and are reusable across the framework (calling from different controller etc.)
But I strongly believe that the fact that CI core developers are separating libraries from helpers, there has to be a reason behind it and I guess, this is the reason waiting for me to discover and get enlightened.
CI developers out there, pls advise.
i think it's better to include an example.
I could have a
class notification_lib {
function set_message() { /*...*/}
function get_message() {/*...*/}
function update_message() {/*...*/}
}
Alternatively, i could also include all the functions into a helper.
In a notification_helper.php file, i will include set_message(), get_message(), update_message()..
Where either way, it still can be reused. So this got me thinking about the decision making point about when exactly do we create a library and a helper particularly in CI.
In a normal (framework-less) php app, the choice is clear as there is no helper, you will just need to create a library in order to reuse codes. But here, in CI, I would like to understand the core developers seperation of libraries and helpers
Well the choice comes down to set of functions or class. The choice is almost the same as a instance class verses a static class.
If you have just a simply group of functions then you only need to make a group of functions. If these group of functions share a lot of data, then you need to make a class that has an instance to store this data in between the method (class function) calls.
Do you have many public or private properties to store relating to your notification messages?
If you use a class, you could set multiple messages through the system then get_messages() could return a private array of messages. That would make it perfect for being a library.
There is a question I ask myself when deciding this that I think will help you as well. The question is: Am I providing a feature to my framework or am I consolidating?
If you have a feature that you are adding to your framework, then you'll want to create a library for that. Form validation, for example, is a feature that you are adding to a framework. Even though you can do form validation without this library, you're creating a standard system for validation which is a feature.
However, there is also a form helper which helps you create the HTML of forms. The big difference from the form validation library is that the form helper isn't creating a new feature, its just a set of related functions that help you write the HTML of forms properly.
Hopefully this differentiation will help you as it has me.
First of all, you should be sure that you understand the difference between CI library and helper class. Helper class is anything that helps any pre-made thing such as array, string, uri, etc; they are there and PHP already provides functions for them but you still create a helper to add more functionality to them.
On the other hand, library can be anything like something you are creating for the first time, any solution which might not be necessarily already out there.
Once you understand this difference fully, taking decision must not be that difficult.
Helper contains a group of functions to help you do a particular task.
Available helpers in CI
Libraries usually contain non-CI specific functionality. Like an image library. Something which is portable between applications.
Available libraries in CI
Source link
If someone ask me what the way you follow when time comes to create Helpers or Libraries.
I think these differences:
Class : In a nutshell, a Class is a blueprint for an object. And an object encapsulates conceptually related State and Responsibility of something in your Application and usually offers an programming interface with which to interact with these. This fosters code reuse and improves maintainability.
Functions : A function is a piece of code which takes one more input in the form of parameter and does some processing and returns a value. You already have seen many functions like fopen() and fread() etc. They are built-in functions but PHP gives you option to create your own functions as well.
So go for Class i.e. libraries if any one point matches
global variable need to use in two or more functions or even one, I hate using Global keyword
default initialization as per each time call or load
some tasks are private to entity not publicly open, think of functions never have public modifiers why?
function to function dependencies i.e. tasks are separated but two or more tasks needs it. Think of validate_email check only for email sending script for to,cc,bcc,etc. all of these needs validate_email.
And Lastly not least all related tasks i.e. functions should be placed in single object or file, it's easier for reference and remembrance.
For Helpers : any point which not matches with libraries
Personally I use libraries for big things, say an FTP-library I built that is a lot faster than CodeIgniters shipped library. This is a class with a lot of methods that share data with each other.
I use helpers for smaller tasks that are not related to a lot of other functionality. Small functions like decorating strings might be an example. Or copying a directory recursively to another location.