Arcade表达式入门学习笔记
许多人在ArcGIS Desktop中使用过表达式、图层过滤、标注等。现在有一种新的跨平台的表达式，叫做Arcade表达式，可以在桌面的ArcGIS Pro、门户、网页端开发、移动端开发共同去使用的一种语言。主要用途有：可视化数据、标注要素、创建弹出窗口的内容。
特点：
即拿即用 -- 通过ArcGIS 写、分享、执行 表达式
轻量化 -- 以最小的影响运行在ArcGIS上
安全 -- 没有可执行代码，该代码不能在ArcGIS以外运行，在ArcGIS程序上下文内使用时才会执行。
表达式语言 -- 编写ArcGIS可以执行的语句
为了ArcGIS使用 -- Esri开发的Arcade为了在ArcGIS中使用
总则：评估和理解表达式的上下文。一些总则提供多个全局变量，其他总则提供只有一个或不提供。
Labeling、Popup、Visualization。Dashboard（2）。Attribute Rules（3）
全局变量：制定表达式里使用的变量
$datastore $feature $layer $map $value $view.scale
这些全局变量被表达式操纵，以生成想要的输出。
表达式的基本语法
输出值、变量、常量、方法、文字、操作符
基本语法
使用模式（工作流）
Arcade工作流
Profile 评估和理解上下文决定提供给表达式的全局变量。Arcade语言提供工具构建表达式的方式有 变量和数据结构，条件语句、循环结构、数学、逻辑、和字符串操作符、用户定义的方法 和 以上所有的集合。
Arcade表达式的基本特征：
1.不区分大小写
2.单行注释//多行注释/* */
3.语句可以跨多行。
4.多条语句以分号分隔，以分号结束语句
5.变量声明使用var
6.使用全局变量获取要素属性。$feature.attributeField
（1）获得连接的数据 $feature.[TABLENAME.POP21] 连接由表格点字段名称组合周围的括号表示
（2）访问图层中的所有要素 $layer
7.使用return返回结果。
相似的编程
数据类型
数组 [name,temp,wind,rh]
布尔 true
时间 Date(2022,3,2)
数据字典 Dictionary("Speed",10,"DIRECTION","southwest");
数值 65
文本 "你好"
操作符
数学运算符-- + - * /
增量运算符-- i++ j--
比较运算符-- == != > <
逻辑运算符-- && ||
编程语言加上一个全面的函数库，用于处理数据、处理日期、用于工作的几何函数.
数据、日期、几何、逻辑、数学、文本和跟踪的内置函数。
Sort() Now() Intersects()
isEmpty() Mean() Trim()
TrackCurrentSpeed
控制语句
条件语句
if() when()
循环语句
for(var i -0; i<MaxVal; i++){
}
用户定义的方法
Function calculateWindSpeed(param1,param2){
}
视频字幕：
Time Caption
0:01- [Rudy] Hello, and welcome to "ArcGIS Arcade: An Introduction."
0:05My name is Rudy Prosser and I'm here with my colleague Allison Rost
0:09to provide you with an overview of the ArcGIS Arcade expression language.
0:16We will introduce you to Arcade by describing
0:18what it is and how it can be used.
0:21I will describe what Arcade is, how the Arcade profiles determine where
0:25you can use Arcade, and the data you can use in your expressions.
0:30I'll then describe some of the basic characteristics of the
0:33Arcade expression language.
0:35Allison will show you how Arcade is used in ArcGIS by using it to visualize data,
0:41label features, and create content for pop-ups.
0:49The ArcGIS Arcade documentation describes Arcade as "...a portable, lightweight,
0:55and secure expression language written for use in ArcGIS."
1:00ArcGIS Arcade is portable because the Arcade expressions you write in one part
1:06of ArcGIS can be shared to the rest of ArcGIS.
1:10You can create an expression for labeling features in a web map layer,
1:14created in an ArcGIS Online or ArcGIS Enterprise, then copy and use that same
1:19expression in ArcGIS Pro for labeling features in a map layer.
1:23And finally, apply that same expression to a FeatureLayer in an
1:27ArcGIS API for JavaScript application.
1:32ArcGIS Arcade is lightweight in that you can use Arcade wherever ArcGIS runs.
1:37You can use it in desktops applications, such as ArcGIS Pro, in browser-based web
1:42applications created in ArcGIS Online or with the ArcGIS API for JavaScript,
1:47or in native applications built for mobile devices.
1:53ArcGIS Arcade is secure in that there's no executable code.
1:58The expressions you write with Arcade cannot be executed outside of ArcGIS.
2:03They only work within an ArcGIS application.
2:07The only time an Arcade expression executes is when it is used.
2:11For example, when you label features in a map, or generate the text for a pop-up,
2:16or check attribute values of a feature that was just edited.
2:20You can't use Arcade to build an application, or run an analysis,
2:24or automate a task.
2:27Arcade runs in specific, well-documented situations.
2:32It's an expression language.
2:34Arcade is used to write statements that when executed by ArcGIS
2:39return results that are used to create labels for features shown on a map, or
2:44provide values used for rendering those features, or to check a feature class
2:49in the geodatabase for valid and invalid attribute data, or to format the data
2:54shown in an ArcGIS dashboards element.
2:58ArcGIS Arcade is a focused language for specifically defined uses in ArcGIS.
3:04Arcade was written to help you make better maps, better interactive apps,
3:09or to provide higher-quality data, or to make data easier to understand.
3:16Arcade does this through the use of profiles.
3:19A profile is a context in which an Arcade expression is evaluated and understood.
3:25Each profile provides specific inputs that you can use in the expression and
3:30expects specific outputs.
3:33Some profiles are generic and usable in more than one part of ArcGIS, for example,
3:38labeling, pop-up, and visualization.
3:41Other profiles are only available in specific parts of ArcGIS, for example,
3:46the dashboard profile is specific to ArcGIS dashboards.
3:51Currently, there are 15 profiles, with 2 profiles, attribute rules
3:56and dashboard, providing more than one sub-profile.
4:01Each profile makes data available to the expression using global variables.
4:06The number of global variables for use in an expression depends
4:09on the profile chosen.
4:12Some profiles supply multiple global variables, other profiles provide only
4:17one or none.
4:19And all these global variables are defined with a dollar sign
4:23as their first character.
4:26These global variables are the inputs which are manipulated by the expression
4:30to generate the desired output.
4:34An Arcade expression is a combination of these global variables
4:38along with constants, variables that you define,
4:42operators and functions organized into one or more ordered statements,
4:48instructions on the operations to perform and the order to perform them in,
4:53returning a value that you can use.
4:56For example, we need to label-able weather stations on our map with each station's
5:02name plus the current temperature and humidity.
5:06We can build an Arcade expression which will provide the text to do just that.
5:11The Arcade language sets the operators, functions, and some of the specific
5:15constants you can use.
5:17The Arcade profile determines the data your expression can manipulate.
5:22You write the expression and ArcGIS evaluates it, generating a
5:27result used to label the features.
5:31Like many of the tasks you perform using ArcGIS, there's a pattern or workflow you
5:36can use when building an Arcade expression.
5:40What you need to do determines the profile you will use, for example,
5:44labeling, or pop-up or, visualization.
5:48The profile identifies the context where the Arcade expression is
5:51evaluated and understood.
5:54The profile also determines the global variables available
5:57for use in the expression.
6:00The global variables provide the data for the expression.
6:03The Arcade language provides the tools for building the expression in the way
6:08of variables and data structures, conditional statements,
6:11looping structures, mathematical, logical, and string operators,
6:16user-defined functions, and the comprehensive collection
6:20of functions you can use to manipulate the data.
6:22The expression, when evaluated, returns the result you need.
6:29Let's take a look at some of the basic characteristics of the
6:32Arcade expression language.
6:35On the left, you see an Arcade expression used to label weather stations.
6:40Some characteristics of Arcade are, it's not case sensitive,
6:44it supports both single line and multiline comments,
6:47a single statement Arcade can span multiple lines, an Arcade expression can
6:54be multiple statements with each statement separated by a semicolon, and all
6:59statements are terminated by semicolons.
7:04Other characteristics are that all variables are declared using var.
7:10You can access feature attributes using the $feature global variable
7:14plus the name of the attribute field values are to be drawn from.
7:18You can access joined data using the $feature global variable
7:23plus the table and field name you're drawing values from.
7:28Joins are indicated by brackets around the table dot field name combination.
7:33You can also access all the features in a layer using the $layer
7:37global variable, and expression results are returned with a return statement.
7:45Another characteristic of Arcade is that it provides familiar programming
7:49data types, array, Boolean, data dictionary, number, and text
7:55as well as ArcGIS-specific data types such as attachments,
7:59FeatureSets, geometry, and portal.
8:04The ArcGIS Arcade language also provides standard operators used in most scripting
8:09and programming languages plus a comprehensive library of functions
8:14for manipulating data, working with dates, geometry functions for working
8:19with spatial data, logical functions, standard mathematical and
8:23statistical functions, and string manipulation functions as well
8:27as tracking functions.
8:31You also get the same flow of control statements you see in other programming
8:34and scripting languages, conditional statements
8:37for making comparisons, looping statements for iterating
8:41through arrays, dictionaries, and FeatureSets, plus you can define
8:45your own functions.
8:49This was a quick look at the Arcade expression language.
8:51You'll find details in the ArcGIS Arcade documentation on the
8:56ArcGIS developer website.
8:58Now, I'd like to turn the presentation over to Allison, so she can show us how
9:02ArcGIS Arcade is used by showing us it in use.
9:09- [Allison] Thanks, Rudy. Now that you understand
9:11the basic structure and logic of ArcGIS Arcade,
9:14I'm going to show you some of the different ways ArcGIS Arcade can be used
9:18to execute custom expressions across ArcGIS.
9:22First, we'll look at how you can start using the labeling and field calculate
9:26profiles in ArcGIS Pro.
9:29We're going to start with writing a custom label expression.
9:32In ArcGIS Pro, I select the layer, the Labeling tab, and then click Label
9:41to enable labels for my layer.
9:43My weather station points are currently being labeled by the OBJECTD field.
9:48I'm going to use the drop down to change the label field to STATION_NAME.
9:56Now you see all of the features of my map are labeled with their station name.
10:01I'm going to go ahead and use ArcGIS Arcade to create a custom expression that
10:05will stack the values from a second field below the station name
10:09for each of my points.
10:11I can do that by clicking on the Expression button.
10:16That opens the Label Class dialog where I can access the expression box.
10:20The expression box has already been populated with the global variable
10:25$feature.STATION_NAME.
10:27When this label expression is applied, the value for a station name is placed as
10:32a label next to each feature.
10:35To create our custom expression, I'm going to use an Arcade constant.
10:40I'm going to add a plus sign, and then I'm going to add the constant,
10:45TextFormatting.NewLine.
10:52This is what's going to force the values from the second field onto a new line
10:57beneath the station name.
11:00I'm going to add a second plus sign, and then I'm going to select the
11:04global variable, $feature.TEMP, from the field list.
11:11I'm going to go ahead and Verify my expression, and it comes back as valid,
11:17so I can Apply.
11:19And now you can see, I have a stacked label with station name
11:23appearing above the current temperature.
11:26Now, I don't really like how my temperature is being
11:28displayed for all my features.
11:31You can see that some of them go out in multiple decimal places.
11:34Instead of adding a new field to the attribute table of my weather
11:38stations layer, I'm going to go ahead and use an Arcade math function called
11:42Round to round my temperature values to zero decimal places.
11:48To do this, in the expression box, I'm going to add
11:52Round an open parenthesis.
11:57Then after the global variable, I'm going to add a comma and tell it,
12:02I want it to round to zero decimal places.
12:05Then I'm going to add a close parenthesis.
12:09I'm going to Verify and it says my expression is valid, so I'm going to go
12:14ahead and Apply.
12:17All right, so this is looking better, but it still isn't
12:20clear that the second value is a temperature.
12:23So I'm going to make one more modification to my expression.
12:27I'm going to go ahead and add some text to the end of my expression by adding a
12:33plus sign and then the text between two quotation marks.
12:41I'll Verify my expression again and then Apply.
12:47Now that we have a well-formed stacked label, I'm going to go ahead and share
12:52this web map to ArcGIS Online, so we can use it for another demo.
12:56I'll do this by clicking Share, Web Map, completing the required information...
13:14...analyzing, and then clicking Share.
13:21While this is publishing, we're going to look at another way we can
13:26label this map using text formatting tags.
13:30Here, we have a duplicate of the map we were just working on,
13:34we used Arcade to create a simple stacked label that we shared to ArcGIS Online.
13:40If you need to create complex labels for an ArcGIS Pro project,
13:45you could choose to use text formatting tags to set the font, font size, color,
13:52style, spacing, background color, and more,
13:55to different sections of your labels.
13:59If we go back to the labeling dialog...
14:06...we can add text formatting tags to the expression in the expression box.
14:11Let's say I want to change the color of the station name to red.
14:15I can do that by adding a color formatting tag around STATION_NAME.
14:40After I add the tag, at the end, I have to close the tag.
14:50Then I can Verify and my expression is valid so I can Apply.
14:55I like this better, but I think it would stand out more if I also made the
15:01station name bold.
15:03I can do this by adding a bold tag.
15:07So right before the color tag, I'm going to add bold, and then
15:15right after, I'm going to close it.
15:24My expression is valid so I can Apply. Okay.
15:30This is looking good for station names, but the temperature
15:33is getting a little lost.
15:35I'm going to resolve this by increasing the size of the font for the temperature
15:38using a font tag.
15:41I'm going to add it before I round the temperature value.
15:50And it's going to be font size equals, and I'm going to go ahead and
15:55make it 12.5. And then I'm going to close our tag.
16:11I'm going to Verify my expression, my expression is valid so now, I can Apply.
16:20I'm happy with these labels.
16:22Just keep in mind that the text formatting tags can only be used in ArcGIS Pro, so I
16:28don't want to share this version of my map as a web map.
16:31Now, before we leave ArcGIS Pro, I want to take a look at one more Arcade
16:35profile called field calculate.
16:39To do that, we're going to navigate to one more map.
16:44In this map, I have a polygon layer that I created from a land cover raster.
16:50I have the grid code from the raster, but I want to add a field to the attribute
16:54table with the land cover description of each code.
16:57When I open the Attribute Table, you see that I've already added a text
17:03field for the land cover description.
17:07I'm going to right-click on that field and click on Calculate Field to open
17:12the field calculator.
17:15I'm going to resize it, and then I'm going to change the expression type from
17:22Python 3 to Arcade.
17:27The first thing I'm going to do is I'm going to create a variable to hold a
17:32dictionary of name value pairs that represent the gridcode
17:37values and their associated descriptions.
17:46One thing to take note of, even though the name value is a number,
17:49in my dictionary, it's always treated as text.
17:53Since the gridcode field is a numeric field, I'll have to cast it into text
17:58in order to compare the two values.
18:00To handle this comparison, I'm going to use a series of if statements.
18:10My first if statement will tell the calculator what to do if the
18:13gridcode is null.
18:15If gridcode is null, I want it to just go ahead and continue.
18:24If gridcode equals equals null...
18:33...continue.
18:35And I'm going to close that expression.
18:39My second if statement will look for any numeric values that are less than 10.
18:44The reason I'm looking for any single digit values is because in order to use
18:49the text function to convert the numeric gridcode into text,
18:54I have to tell the function how to format the result.
18:57I do this by specifying how many digits to the left of the decimal place should be
19:02considered by placing a single zero at the end.
19:06This is what the expression looks like.
19:10If gridcode is less than 10, I'm going to have it return the dictionary
19:24value that matches the Text of gridcode...
19:40...to one decimal place.
19:47And then we're going to close our expression.
19:52I'm going to go ahead and Verify, and my expression is valid.
20:00My third statement will look for any numeric values that are 10 or greater.
20:04That way, I can set the format for these values to two digits
20:08to the left of the decimal place.
20:14I'm going to go ahead and copy my previous statement and change it to
20:22greater than or equal to 10.
20:24Then, I'm going to add a second zero to represent that second decimal place.
20:32I'm going to go ahead and Verify my expression again, and it's valid,
20:38so I'm going to go ahead and Apply it.
20:47And now, you can see the description field has been populated with the value that
20:51corresponds to the gridcode.
20:54If I do a sort descending, my woody wetlands are a gridcode 90.
20:59Sort ascending, my barren land is a gridcode of 31.
21:03These were just a few examples of how ArcGIS Arcade can be used in ArcGIS Pro.
21:08In my next demo, I'll show some examples of using the visualization and pop-up
21:13profiles in ArcGIS Online.
21:21In this demo, we transitioned from ArcGIS Pro to ArcGIS Online.
21:27I want to start by emphasizing that ArcGIS Arcade is portable,
21:32meaning it can be used across ArcGIS.
21:35This is the weather map of stations I shared from ArcGIS Pro to ArcGIS Online
21:39in my previous demo.
21:42As you can see, each station has an associated stacked label.
21:46We can review the Arcade expression used to label these features by clicking
21:51on Layers, selecting the layer, selecting Labels, opening our Custom label
22:02field expression, and reviewing the expression in the dialog.
22:09So as you can see, the same custom expression that we wrote in ArcGIS Pro is
22:15still being applied in an ArcGIS Online web map.
22:18If we wanted to change or modify our expression, we'd be able to do so
22:22in this dialog.
22:24Through it, you have access to your global variables, a list of Functions,
22:30and Constants, like TextFormatting.NewLine,
22:34that we're using in our current expression.
22:36I'm not going to change our expression right now,
22:38so I'm going to go ahead and tell it OK.
22:42Next, we're going to take a look at how you can use Arcade to create a custom
22:46style for the features in your map.
22:49Before we start styling our map, I'm going to go ahead and change the
22:52visible range for our labels to countries-small.
23:00Then I'm going to zoom out so we can see more of our features.
23:06Since our weather stations layer is still selected, I'm going to go ahead and click
23:10on Styles to open the Styles pane.
23:13The weather station points currently have a single symbol applied.
23:16I'm going to write a custom attribute expression in Arcade to help me style this
23:20layer so that it's easy to identify areas with cold, mild, and hot temperatures.
23:26To do that, I'm going to click on Expression to access the editor window.
23:30The first thing I like to do in the editor window is
23:33to create a name for the expression.
23:36This makes it easier to identify it if I end up writing more than one.
23:41So I'm going to go ahead and change the name to Temp Categories,
23:49and then I'm going to click Save.
23:53For this expression, I'm going to use a logic function called
23:56When to evaluate the value in the temp field and return a defined label.
24:02I'm going to start by defining a variable called tempcategory,
24:07which I'm going to set as equal to the result of When.
24:10So variable tempcategory equals to When.
24:17And to make this a little easier for you to read, I'm just going to
24:21go ahead and space it out a little.
24:23And so I'm going to get the Round of our global variable TEMP
24:31to the zero decimal place.
24:35And when that value is less than or equal to 32, I would like it to return
24:42"Below Freezing" and I'm going to go ahead and reuse.
24:53So if that value is greater than 32 and less than 60, then I'd like it to return
25:10"Cool to Mild."
25:17And finally, if the value is greater than or equal to 60, I'd like it to return
25:30"Warm to Hot."
25:34And with When, I need to provide a final value that will be returned in the event
25:40that none of these expressions return true.
25:43So I'm just going to make that null.
25:46So if none of these are true, I'm going to get null back.
25:53I'm going to return the result of When.
26:02There we go. And then I am going to Test to make sure that my expression is valid.
26:10So as you see, the result was below freezing so I know that my
26:15expression works successfully.
26:18So I'm going to go ahead and tell it OK.
26:20And as you can see, my expression is now accessible under choose attributes.
26:26And thanks to smart mapping, the weather stations now have a unique
26:31symbol style applied.
26:33So I'm just going to go ahead and click on Style options, and then I'm going to
26:37switch out the color ramp for something that is a little more
26:40representative of temperatures.
26:44Then I'm just going to tell it Done and Done, and my features look great.
26:49So I'm almost ready to share my map.
26:52There's one more option that I want to configure for my weather stations before I
26:56share this out, and that's going to be the pop-ups.
26:59I'm going to click on Configure pop-ups to open the pop-ups pane and an example of my
27:05current pop-up configuration.
27:07The {STATION_NAME} is currently being used as a title for my pop-up, but I'd
27:13like to improve it by adding the state.
27:15In the field list, by default, all the fields in my layer are listed.
27:19I have a lot of fields that aren't relevant for my audience like OBJECTID,
27:26that aren't formatted like TEMP, or that lack context like the ICAO field.
27:35So I'm going to go ahead and reconfigure the pop-ups using Arcade expressions.
27:39So only necessary and well-formatted fields appear in the pop-up window.
27:44The first thing I'm going to do is go ahead and remove all the fields from my
27:48pop-up by clicking Fields list, and then
27:51clicking X to remove the ones I don't want.
28:05Now I'm ready to start adding my expressions.
28:07I'm going to go ahead and close my field list, and I'm going to click
28:11on Manage expressions.
28:14This is where I can access the Add expression button and open up my editor.
28:21I'm going to go ahead and create an expression to use
28:23as the title of my pop-up.
28:25So I'm going to go ahead and edit the name, and I'm going to call this
28:31Station and State.
28:37Now we're ready to start writing our expression.
28:39But you may notice something different about some of the global variables
28:43that we now have access to.
28:45We've been working with $feature up to this point but we now have three
28:49additional options that I want to take a moment to discuss.
28:52The first is $layer.
28:55$layer is actually, in this case, a FeatureSet.
28:58A FeatureSet represents a connection to a set of features.
29:02So if I wanted to find the maximum value of an entire field,
29:07I'd use the $layer variable.
29:10The next I'm going to point to is $map.
29:13The $map variable is a FeatureSet collection which gives you access
29:18to FeatureLayers in the same map so you could access field values or geometry
29:25of other layers to use in the calculation of your expression.
29:29The last is $datastore. So a $datastore is also a type of FeatureSet collection,
29:35and this gives you access to layers in the same feature service or database as the
29:40layer whose pop-ups are being configured even
29:44if they haven't been added to the map.
29:46In this example, we're going to continue using our $feature global variable.
29:50So I'm just going to go ahead and click on the arrow to access my fields, and I'm
29:56going to go ahead and add my STATION_NAME.
30:03Now, the field that contains the state information also contains the country,
30:08and I'd like to remove the country because it makes the title a little too long.
30:12So I'm going to use a Replace function to remove
30:16the text that I'm not interested in.
30:18I'm going to do that by adding a plus sign, and then a comma and a space so my
30:23title is easy to read.
30:26I'm going to add another plus sign, and then Replace,
30:30and then I'm going to find my country field.
30:33Going to add COUNTRY, and then I'm going to tell it what text to remove,
30:40United States of America.
30:45And then I'm going to tell it what to replace it with, which in this instance,
30:49is going to be nothing. Make sure that's closed. All right.
30:54And now, let's go ahead and Test.
30:57Well, as you see, I have an extra comma.
31:00So let's go ahead and remove that.
31:05So it would be comma, space, United States of America.
31:09Let's try this one more time. There we go. Much better.
31:12So now, we have our title expression ready. I'm going to go ahead and click OK.
31:17And now, you can see that it's been added right here in our pop-up expressions pane.
31:24We're going to go ahead and add a few more expressions, and then we're going to apply
31:27these to our pop-up.
31:29So the first additional expression we're going to add,
31:32we're going to call Temperature.
31:40That's just going to Round our temperature like we've done
31:42before and add degree Fahrenheit.
31:45Let's get and Test it.
31:48So I'm going to go ahead and tell this one, OK.
31:52Our next expression, we're going to call Wind Chill.
32:01Okay.
32:05And we're just going to Round Wind_Chill and then add degrees Fahrenheit again.
32:08Let's Test it.
32:11Looks good, so we're going to tell this, OK.
32:14And then our last expression, we're going to call Wind Direction.
32:24I'm just going to tell this to Save, and we're going to write this expression
32:29similar to what we did in one of our previous expressions when
32:33we use the When function.
32:35So we're going to add two variables, one for wind direction,
32:39and one for WIND_SPEED, then we're going to create
32:42a variable for the wind function.
32:45In this case, we're first going to look at SPEED and if it's zero,
32:48we're not going to assign a direction.
32:50Then we're going to look at direction and to determine whether the wind is
32:53blowing north, northeast, east, southeast, south, southwest, etc.
32:59And if none of these are true, then we're just going to return, null.
33:03So the last thing we're going to do is return SPEED plus miles per hour,
33:15because we'd like it to have a label, and then the direction
33:19from our When function. Let's go ahead and give this a Test.
33:25Nine miles per hour west. That looks good to me.
33:27And we're going to tell it, OK.
33:30And now we're ready to configure our pop-ups by applying our expressions.
33:34So we're going to go back, and then we're going to first change our {STATION_NAME}.
33:40I'm going to remove the current title.
33:44I'm going to click on the option to open my field list.
33:48And as you go through the field list, you're going to see my expression,
33:52state and station is now available.
33:55I'm going to go ahead and click on state and station and apply that.
33:59All right. So that's looking a little better.
34:01And now when I click on my field list, I'm going to be able to click
34:06on Select fields.
34:08And again, you're going to see my expressions available.
34:11So here's Temperature, Wind Chill, and Wind Direction, and I can click Done.
34:16And now, my pop-up has been configured and I'm ready to share my map.
34:22For our next demo, we'll look at using ArcGIS Arcade to configure
34:27an ArcGIS dashboard.
34:31In this demo, we're going to take a look at how ArcGIS Arcade can be used to help
34:35configure an ArcGIS dashboard.
34:38I have a simple dashboard here that I created using our temperature labels map
34:42that we created and configured in the previous two demos.
34:46Right now, it's set with historic data, and there's an option to filter that data
34:51based on dates.
34:53I'm going to go ahead and select a date so we have some data to work with.
34:59Now, our points are available, and there's a list of areas that had a wind speed
35:05greater than 37 miles per hour and an average indicator.
35:10So the average on this day was 19.9 miles per hour.
35:14We're going to use Arcade to reformat these two elements.
35:17We're going to start with formatting the list element.
35:20My goal is to create an expression that sets the background color for each of the
35:24list items based on the wind speed.
35:27To do this, I'm going to hover over the list, select Configure, click on List,
35:34and then I can Enable advanced formatting.
35:38In the expression box, a return has already been set up for me
35:41that includes the default system-defined properties.
35:44In this instance, system-defined properties are settings you would
35:48otherwise configure in an element, such as text and background color.
35:53For this expression, I'm going to use a logic function
35:55called IIF, which is going to evaluate a condition and return one result if it's
36:00true and another if it's false.
36:04I'm going to make this a little larger and set up a variable called speedColor and
36:14set that equal to IIF WIND_SPEED is greater than or equal to 51.
36:29And then I just have two hex codes.
36:31So if it's greater than or equal to 51, it'll be red-orange,
36:34and if not, it will be yellow.
36:38So in order to apply my new speedColor variable, I'm going to take the variable
36:44name and place it next to backgroundColor. And let's just give this a Test.
36:52And now you see, when I look at my result, the value for backgroundColor
36:57is one of my hex codes.
36:59There's one more change that I want to make before we leave the advanced
37:02formatting editor, and that's going to be adding the state after the station name.
37:08To do that, I'm going to create one more variable for stateName.
37:12And as you remember, I was getting state name from
37:17the country which also included the country.
37:19So I'm going to use Replace to remove the COUNTRY
37:24so that I'm just sharing the state name.
37:29So I'm going to put United States of America, and then I'm going to set the
37:38result as blank because I don't want it to return anything.
37:41So now, we're going to go back over to my return, and you'll see there's no
37:46system-defined property for text.
37:49So what I need to do is add my variable as an attribute.
37:53So there's a predefined attribute dictionary.
37:57So I'm going to ho head and uncomment these lines,
38:00and it gives me this syntax here.
38:04I'm just going to remove this and put state, and then I would like state to be
38:10equal to my stateName.
38:14Okay? Let's go ahead and Test this. All right.
38:16So now we see my attributes return dictionary and my
38:19backgroundColor returns my hex.
38:21So I'm going to go ahead and go back over to my List options and then scroll
38:27down to my Line item template.
38:30So {STATION_NAME} is currently what's set for my line item.
38:34I'm going to add a comma and a space, and then I'm going
38:37to add the state attribute that I created.
38:40So expression/state. All right. So that's looking better.
38:45Now I have both the station name and the state.
38:48So I'm going to go ahead and say, Done.
38:51And now, you can see my list element shows weather stations with wind speeds greater
38:56than or equal to 37 miles per hour in yellow and weather stations reporting wind
39:01speeds greater than or equal to 51 miles per hour in red.
39:05And finally, we're going to configure this indicator so that the custom wind icon
39:09that I uploaded only appears when the average
39:12wind speed is over 10 miles per hour.
39:15To do that, we're going to start configuring our indicator.
39:20We're going to click on Indicator, and then we're going
39:23to Enable advanced formatting.
39:27If I scroll to the bottom of the indicator options pane, you'll see the custom icon
39:32I added, its name is icon1.
39:35So we're going to scroll back up, and we're going to write an expression that
39:40displays icon1 when the average wind speed is greater than or equal to
39:4510 miles per hour.
39:47To get a little more room, I'm going to go ahead and expand
39:49our editor, then I'm going to create a variable that's going to reference icon1.
39:59Next, I'm going to create an if statement.
40:02So if WIND_SPEED is less than 10...I would like icon to be blank.
40:16So now, we're ready to set the icon name in our system-defined properties
40:22to our icon variable.
40:26And now, I can do a couple of quick improvements.
40:28I'm going to go ahead and round the WIND_SPEED that appears in my indicator,
40:34and I'm also going to add some topText.
40:39So it's really easy to make changes by filling out the system-defined properties.
40:43So I'm just going to make this "Average Wind Speed" so folks understand what the
40:48indicator is meant to show.
40:51Now, whether the icon appears or not in our Test will depend on what wind speed is
40:57currently being considered.
40:59So just because it's not here doesn't mean it's not working.
41:02Let's go ahead and exit out of the expanded view, go back
41:06over to our indicator options.
41:08All right, and now we see 17 miles per hour for an average and I do see my icon.
41:13So let's go ahead and click Done. And we are going to test this out.
41:18So here, we have an average wind speed of 20 miles per hour.
41:21So let's go ahead and change the dates.
41:27And now, we have an average wind speed of 10 and you can see that my icon is gone.
41:32One last thing that I want to point out about this dashboard is I can click on a
41:37location and as you see, the labels that I set up in ArcGIS Pro,
41:45and if I click on one of the weather stations, the pop-up that I configured
41:49in Map Viewer is still accessible.
41:52For my last demo, I'm going to show some examples of using ArcGIS Arcade in a
41:56JavaScript application, and then show you where you can get
41:59started using ArcGIS Arcade.
42:05As you've seen in my prior demos, it's easy to use
42:08ArcGIS Arcade across ArcGIS.
42:11Now we're going to take a look at how you can use ArcGIS Arcade
42:14in a custom JavaScript application.
42:16On the left, I have the code for my application.
42:20It was written using the ArcGIS JavaScript API, Version 4.19.
42:25Currently, all it's doing is grabbing the WebMap and weather stations layer that I
42:30published from ArcGIS Pro in one of my prior demos.
42:34If we go over to the map, you'll see that we can interact
42:37with it just like we did the web map.
42:39I can click on a feature and return with the formatted pop-ups.
42:44If I zoom in on the map, you'll see that my labels appear.
42:51But what if my layer didn't currently have labels applied?
42:54I could use ArcGIS Arcade within my JavaScript application to create labels.
43:01I'm going to show you what that looks like.
43:03So I have a second demo here, and you see that I have labels that now appear
43:08for the entire United States.
43:11These labels look a little bit different because I've added the wind speed.
43:14And that was done in the JavaScript API by adding a script element,
43:22and I think the syntax is going to look familiar.
43:25We set our variable for wind direction, we set our variable for WIND_SPEED,
43:30and then we set a variable that calls the When function.
43:35These are all expressions that I demonstrated writing in my previous demos.
43:42In the end, we returned concatenated labels and we format it with
43:48TextFormatting.NewLine, then we close our script element, and we're
43:53going to call it within our script.
43:57Within labelingInfo, we're going to call labelExpressionInfo
44:03and then we're going to have that expression, getElementById,
44:07our label-expression.
44:09And it's as easy as that to relabel a map using Arcade in the JavaScript API.
44:16By now, you might be wondering, "How can I get started
44:18with ArcGIS Arcade?"
44:20So I want to point out that at developers.arcgis.com/arcade,
44:26you're going to find the ArcGIS Arcade documentation.
44:30We have a Guide that includes Getting Started and sections on Structure and
44:34Logic that explains some of the concepts that Rudy went over earlier.
44:40There's a Function Reference where you can look up the syntax for all of the
44:43different functions, and there's even an ArcGIS Arcade playground where you can
44:48access different profiles to test Arcade syntax and functions.
44:54This concludes the technical presentation.
