using knockout with multiple views - how best to structure API - api

I have a knockout application I am building that has multiple viewModels in one page.
I have been mocking data so far but I am now building the API that will run it.
My question is what do I do with complex viewModels with regards to the API.
For example I have a 'add company' page that has the following tabs:-
Company info (name, address, etc.)
People at company (multiple people)
Insurance Documentation (3 different types)
I currently have each of these as separate viewModels.
When I press save I am now confused what is the best way to do things.
If I send all 3 viewModels bundled together (add them to one master viewModel) then it becomes easy to ensure that IDs all line up but that doesn't seem very modular or a good idea and breaks the idea of being 'API Centric'.
However if I send each viewModel to a different API end-point how do I ensure that the ID's match-up correctly (people -> company) etc.
At the moment I am looking at two options:-
When press 'add new' create a blank company on the database and grab its ID -> use this to match everything up.
OR -
When I press save send the new company up first, then when response comes back as (hopefully) ok then upload the rest of the information to their respective end-points using the now correct ID.
Both seem messy so I am wondering what is the 'accepted' best way to do this??

Your second approach is how I would do it, pressing Save would send the Company model first. Then once you receive the 'OK' response with the Company id, in the callback you can add it to the other models and send them up.
Nothing messy about that, just standard asynchronous behaviour.

Related

GET method with API's

I am not familiar with API's so I was hoping someone could help me with a question I have. My company uses Greenhouse as their hiring software for people to apply and we are redoing our career site to be more custom. They want a page where we can display each department with a text icon that has the number of positions open in that department that updates itself and when you go into that page it wants to display the positions for that department a long with the location they are in.
In the Greenhouse.io API section they say
"This is useful for reporting purposes, or for customers who have
built their own tools that they want to use with Greenhouse. GET
methods include Offices, Departments, Candidates, Activity Feed,
Applications, Scorecards, Scheduled Interviews, Offers, Jobs, Stages,
Job Post, Rejection Reasons, Email Templates, Users, and Sources."
Does this GET method mean I can pull those pieces from the API and display them where ever we need to in the site and it will update automatically? I'm primarily a web designer so this info is a bit new to me.
The GET refers in fact to the HTTP methods. Generally, you call the api with GET to retrieve data.
If you want to insert a new data with api, you will use POST for instance.
You can see those http methods here:
http://www.restapitutorial.com/lessons/httpmethods.html

RESTfully creating object graphs

I'm trying to wrap my head around how to design a RESTful API for creating object graphs. For example, think of an eCommerce API, where resources have the following relationships:
Order (the main object)
Has-many Addresses
Has-many Order Line items (what does the order consist of)
Has-many Payments
Has-many Contact Info
The Order resource usually makes sense along with it's associations. In isolation, it's just a dumb container with no business significance. However, each of the associated objects has a life of it's own and may need to be manipulated independently, eg. editing the shipping address of an order, changing the contact info against an order, removing a line-item from an order after it has been placed, etc.
There are two options for designing the API:
The Order API endpoint intelligently creates itself AND its associated resources by processing "nested resource" in the content sent to POST /orders
The Order resource only creates itself and the client has to make follow-up POST requests to newly created endpoints, like POST /orders/123/addresses, PUT /orders/123/line-items/987, etc.
While the second option is simpler to implement at the server-side, it makes the client do extra work for 80% of the use-cases.
The first option has the following open questions:
How does one communicate the URL for the newly created resource? The Location header can communicate only one URL, however the server would've potentially created multiple resources.
How does one deal with errors? What if one of the associons has an error? Do we reject the entire object graph? How is that error communicated to the client?
What's the RESTful + pragmatic way of dealing with this?
How I handle this is the first way. You should not assume that a client will make all the requests it needs to. Create all the entities on the one request.
Depending on your use case you may also want to enforce an 'all-or-nothing' approach in creating the entities; ie, if something falls, everything rolls back. You can do this by using a transaction on your database (which you also can't do if everything is done through separate requests). Determining if this is the behavior you want is very specific to your situation. For instance, if you are creating an order statement you may which to employ this (you dont want to create an order that's missing items), however if you are uploading photos it may be fine.
For returning the links to the client, I always return a JSON object. You could easily populate this object with links to each of the resources created. This way the client can determine how to behave after a successful post.
Both options can be implemented RESTful. You ask:
How does one communicate the URL for the newly created resource? The Location header can communicate only one URL, however the server would've potentially created multiple resources.
This would be done the same way you communicate linkss to other Resources in the GET case. Use link elements or what ever your method is to embed the URL of a Resource into a Representation.

REST best practices: should a store also return metadata?

I'm building my first REST API (at least trying) for a personal project.
In this project there are resources called players which hold can be in a team. According to REST API design rulebook a resource should be made either to be a document or a store and one should keeps these roles as segregated as possible.
Yet I would like to append some metadata to the team resource, eg the date the team was founded. Is it okay then for GET /teams/atlanta to return this metadata (making it a document) alongside the list of players in the team (making it a store).
Is this a good idea? If so why? If not why not and how to solve this better?
I know there are no rules to developing a REST API, but there are good practices and I would like to adhere to those. Please also not that this is really my first REST API so pardon my ignorance if there is any.
I would recommend having GET /teams/atlanta return just the information about the team, such as the founding date that you mention, and then having GET /teams/atlanta/players return the list of players for that team. These distinctions become more important when you are presenting an API that uses HTTP methods other than GET.
For example, if you wanted to add a player to a team - this would be a lot easier if you could just POST a player object to /teams/atlanta/players than if you had to PUT the whole team object to /teams/atlanta every time you wanted to add one individual player.
If your API only allows retrieval of data, and if it is for a specific client application, there is an argument for combining all the team data into one object to save the client having to make additional requests for the data, but bear in mind that it is less flexible.
Your application may want to display a list of teams by calling GET /teams but you probably wouldn't want all of the player information included in each object in the list as this is quite a lot of data, but if GET /teams/atlanta returns player information then it would be inconsistent not to include it in the list version too.
I would personally favour splitting up the resources as I've suggested, and live with the fact the client may need to make an extra request or two.

Linking actions on two tables

Sorry the title isn't very descriptive, but here is what I'm trying to do:
I am making a website that handles student group funding requests. A particular request for funding could involve any number of items. I have two tables: requests and items. A group begins a request by filling out a "request" form, which contains a brief summary of the request, a category (speaker, advertising, etc.), and some other fields necessary for the bureaucratic process. That works fine and was handled pretty much entirely by scaffolding. The problem I'm having is with the "items". I would like the user to click the "submit" button on the new request form and be taken to another page at which he can add any number of items to the items table, all containing in a field the id of the request he just submitted.
The front end appearance doesn't really matter - it could all be on one page - what's important is that the user submits information to one table and then submits information to a second table, with the info sent to the second table containing something that connects it to the information just submitted to the first table.
As you can probably guess, I'm pretty new at rails (I went through the book Head First Rails and I'm working on my first project), so I'm looking for a general explanation about how this can be accomplished.
I recommend you to read / watch this tutorial. It is quite good.
UPDATE:
http://railscasts.com/episodes/196-nested-model-form-part-1
Hope it helps.

How to decide whether to split up a VB.Net application and, if so, how to split it up?

I have 2 1/2 years experience of VB.Net, mostly self taught, so please bear with me if I seem rather noobish still and do not know some of the basics. I would recommend you grab a cup of tea before starting on this, as it appears to have got quite long...
I currently have a rather large application (VB.Net website) of over 15000 lines of code at the last count. It does not do retail or anything particularly complex like that - it is literally just a wholesale viewing website with admin frontend, catalogue / catalogue management system and pageview system.
I don't really know much about how .Net applications work in the background - whether they are all loaded on the same thread or if each has its own thread... I just know how to code them, or at least like to think I do... :-)
Basically my application is set up as follows:
There are two different areas - the customer area and the administration frontend.
The main part of the customer frontend is the Catalogue. The MasterPage will load a list of products but that's all, and this is common to all the customer frontend pages.
I tend to work on only one or several parts of the application at a time before uploading the changes. So, for example, I may alter the hierarchy of the Catalogue and change the Catalogue page to match the hierarchy change whilst leaving everything else alone.
The pageview database is getting really quite large and so it is getting rather slow when the application is first requested due to the way it works.
The application timeout is set to 5 minutes - don't know how to change it, I have even tried asking this question on here and seem to remember the solution was quite complex and I was recommended not to change it, but if a customer requests the application 5 minutes after the last page view then it will reload the application from scratch. This means there is a very slow page load whenever it exceeds 5 minutes of inactivity.
I am not sure if this needs consideration to determine how best to split the application up, if at all, but each part of the catalogue system is set up as follows:
A Manager class at the top level, which is used by the admin frontend to add, edit and remove items of the specified type and the customer frontend to retrieve a list of items of the specified type. For example the "RangeManager" will contain a list of product "Ranges" and will be used to interact with these from the customer frontend.
An Item class, for example Range, which contains a list of Attributes. For example Name, Description, Visible, Created, CreatedBy and so on. The form for adding / editing loops through these to display relevant controls for the administrator. For example a Checkbox for BooleanAttribute.
An Attribute class, which can be of type StringAttribute, BooleanAttribute, IntegerAttribute and so on. There are also custom Attributes (not just datatypes) such as RangeAttribute, UserAttribute and so on. These are given a data field which is used to get a piece of data specific to the item it is contained in when it is first requested. Basically the Item is given a DataRow which is stored and accessed by Attributes only when they are first requested.
When one item is requested from a specific manager is requested, the manager will loop through all the items in the database and create a new instance of the item class. For example when a Range is requested from the RangeManager, the RangeManager will loop through all of the DataRows in the Ranges table and create a new instance of Range for each one. As stated above it simply creates a new instance with the DataRow, rather than loading all the data into it there and then. The Attributes themselves fetch the relevant data from the DataRow as and when they're first requested.
It just seems a tad stupid, in my mind, to recompile and upload the entire application every time I fix a minor bug or a spelling mistake for a word which is in the code behind (for example if I set the text of a Label dynamically). A fix / change to the Catalogue page, the way it is now, may mean a customer trying to view the Contact page, which is in no way related to the Catalogue page apart from by having the same MasterPage, cannot do so because the DLL is being uploaded.
Basically my question is, given my current situation, how would people suggest I change the architecture of the application by way of splitting it into multiple applications? I mean would it be just customer / admin, or customer / admin and pageviews, or some other way? Or not at all? Are there any other alternatives which I have not mentioned here? Could web services come in handy here? Like split the catalogue itself into a different application and just have the masterpage for all the other pages use a web service to get the names of the products to list on the left hand side? Am I just way WAY over-complicating things? Judging by the length of this question I probably am, and it wouldn't be the first time... I have tried to keep it short, but I always fail... :-)
Many thanks in advance, and sorry if I have just totally confused you!
Regards,
Richard
15000 LOC is not really all that big.
It sounds like you are not pre-compiling your site for publishing. You may want to read this: http://msdn.microsoft.com/en-us/library/1y1404zt(v=vs.80).aspx
Recompiling and uploading the application is the best way to do it. If all you are changing is your markup, that can be uploaded individually (e.g. changing some html layout in an aspx page).
I don't know what you mean here by application timeout, but if your app domain recycles every 5 minutes, then that doesn't seem right at all. You should look into this.
Also, if you find yourself working on various different parts of the site (i.e. many different changes), but need to deploy only some items in isolation, then you should look into how you are using your source control tools (you are using one, aren't you?). Look into something like GIT and branching/merging.
Start by reading:
Application Architecture Guide