In addition to the excerpts quoted below, you can read the first 15% of the book online for free at Smashwords.com.
"...if you want to write automated strategies for NinjaTrader, you must be able to write indicators. Chances are extremely high that the strategies you write will rely on custom indicators that you write. In fact, the strategies you write will no doubt pull together information from multiple indicators to make trade decisions. (And that's why the trade entry decision Indicator is added to the book.)
A typical strategy will perform the following tasks:
• Analyze market data
• Make trade entry decisions
• Place buy or sell orders
• Monitor and manage open orders
• Monitor and manage open positions
• Close trades via buy or sell orders such as stop-loss and profit target orders
The first task, analyze market data, will no doubt rely on information provided by one or more indicators—probably many indicators across multiple timeframes and possibly across multiple instruments. Additionally, you may need some indicators to help your strategy determine logical entry and exit price points based on support, resistance, time, and other factors. Determining trade size is another consideration that may, in part, rely on indicator-provided information. In a sense, indicators are the building blocks of strategies."
Chapter 2—Key Concept—Where’s the Data?
"Think of it this way: You're painting a picture and someone else has already put quite a bit of paint on the canvas. The purpose of this chapter is to help you understand what "paint" or structure is already there so you understand how to work with it. You can use what’s there and add much to it."
Chapter 3—Creating Indicators
"For our first example, let's create an indicator that does not plot anything and does not sound any alerts. Its purpose is purely to add data elements to bars in the chart and make that available to other Indicators. ..."
"This time, let's create a new Indicator that will plot the up and down volumes in a panel below the price panel in the chart. This new indicator will use the values collected in the UpDownTradeVolumeNV Indicator just created."
Chapter 12—A Trade Setup Entry Indicator
"The goal here is more than just putting together a demonstration indicator that recognizes what might be a good trade setup and flagging it so that the user can act on it. The goal also includes establishing a design pattern and code framework that can be used for additional trade setups once the initial one is complete. The idea is that a programmer could write code logic to implement numerous trade setups, each of which is geared toward a specific set of market conditions, thus identifying multiple trade opportunities over a variety of conditions."