Notes from the field

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Tutorials, code, and lessons from building premium GIS — ArcGIS automation, portal administration, the modern Esri stack, and open-source spatial workflows.

A desktop browser layout built from calcite-shell regions: header, left action bar, a side panel of list items, a map, a floating dialog and a footer, with the detached pieces linked alongside. At the center, a breakpoint node between a monitor and a phone icon sits above a code block. On the right, the same app as two phones; the upper one keeps the desktop side panel and is marked with a grey cross, the lower one collapses it into a sheet over the map and is marked with a blue check.
Featured · Calcite Design System

calcite-shell decides where things go, not when they move — the Calcite 5.x layout frame, and the small-screen code it leaves to you

What calcite-shell does at Calcite 5.x: ten named slots, shell-panels placed by slot, and slotted dialogs kept inside its box. What it does not do: adapt to small screens. A tested small-screen sample with its caveat, the 5.0 leftovers to clean up, and what 30 ATS builds show.

October 12, 2026 · 11 min read · Layout

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A blue globe with a latitude and longitude graticule sits at the center, joined by lines to five panels: a gridded globe with an angle arc, a world map cut into UTM zone strips, State Plane zones across the United States beside a crosshair, nested MGRS squares that zoom into finer grids, and a grid reference read right then up, with three zoom levels of the same point.
Maps SDK for JavaScript

Coordinate grid maps explained — graticules, UTM zones, MGRS squares and State Plane, and how to read a grid reference

What a coordinate grid map shows: graticules versus projected grids, UTM zones and latitude bands, MGRS and USNG references, and State Plane. How to read a grid reference digit by digit, the zone, band and datum mix-ups to avoid, how ArcGIS Pro draws grids, and how Pro and the Maps SDK convert coordinates.

October 7, 2026 · 19 min read · Coordinate grids
A greyed-out map app on the left shows blank pins and an empty popup, beside three failed reads - a table, a layer stack and a JSON response - each ending in a grey cross. In the center, a magnifier and shield over a field list and a layer tree, one row highlighted in each, joined by a blue line to the service icon below. On the right, a blue check and the same app working: bright pins and a filled popup.
ArcGIS Online

The field key and the /0 you never chose — reading feature service attributes and sublayer ids the way the service defines them

Two values that feature service code tends to hard-code are chosen by the service: the attribute key it indexes and the /0 it appends. Measured on Living Atlas and USGS services: why attributes read undefined, why a missing layer is HTTP 200, and how to resolve both at run time.

October 5, 2026 · 17 min read · Feature services
Three layer icons, a sparkle-marked layer stack, a highlighted state cluster inside a focus ring and two overlapping translucent shapes, feed a large US map where a group of central states glows blue against a grey country; the map saves to a web map document with a database cylinder beneath and fans out to a live map viewer marked with a check, a 3D scene and a print page both marked with an X, and a camera leading to a small screenshot.
ArcGIS Online

Local focus in ArcGIS Online — the three properties Map Viewer saves into the web map, and the two places they stop

Graying out every county but one in Map Viewer writes three presentation properties into the web map item and changes nothing in the data. What gets saved, where the group-layer blending rule is documented, why the mask is not a boundary, and how both ArcGIS print paths lose it: one outright, one at screen resolution.

September 28, 2026 · 30 min read · Map Viewer
Three source cards on the left, a small map with zoom buttons, a stack of Calcite-style controls and a record row, each tagged with a code bracket, flow by blue arrows into a central registry column of three typed slots guarded by a clock and a shield check; a cube, a circle and a triangle then flow right into an app window showing a map with a pin, a control rail and a feature row, with a return arrow carrying an event back.
Calcite Design System

One JSX tag for three kinds of custom element — arcgis-map, Calcite and your own Lit element in a React 19 app

In React 19, arcgis-map, a Calcite element and a Lit element you wrote are one kind of thing: custom elements in plain JSX, no wrapper. But React assigns an object prop as a property only when that property already exists on the element — plus the event casing and TypeScript rules that decide whether it works.

September 28, 2026 · 20 min read · Custom elements
A code icon on the left sends three rows toward a blue shield with a check mark: two blue rows pass through, and a gray row is stopped at an X, with a dashed line back to the shield. Four panels across the top feed the shield: a set of shape symbols, a layer stack splitting into two tables, paired fields marked with two checks and one X, and a gear feeding a table. Past the shield the rows land in a database, and a magnifier panel on the right inspects the stored table, marking two rows with checks and one with an X.
ArcGIS Pro

ArcGIS Pro geodatabase guardrails are not interchangeable — what domains, subtypes, contingent values and attribute rules do when a script writes the data

Domains and contingent values shape what an editor is offered in ArcGIS Pro, and subtypes supply per-category defaults and domains. Measured on ArcGIS Pro 3.7.1 file and mobile geodatabases, at the tools’ defaults, none of them stopped a bad value written by an ArcPy insert cursor, Calculate Field or Append; a constraint attribute rule did. A Domain() constraint rule, what ENFORCE_DOMAINS changes and what it misses, loads that succeed with refused rows, and what happens to attribute rules in an enterprise geodatabase, on ArcGIS Online and in web and Native apps.

September 21, 2026 · 25 min read · Data quality
A stack of spreadsheets on the left, topped by a round sync badge, points by arrow to a tile holding a blue check shield and on to a card where a blue database cylinder sits among four corner tiles showing stacked layers, a chain link, a paperclip and a clock ringed by arrows, and from that card two curves branch right, the upper curve to a pale panel where a gray database cylinder points to a blank table and then to a filled blue table, with an arrow arcing from the blank table to the blue one, and the lower curve to a cyan outlined panel where a blue database cylinder marked with a small check shield fans out to three round badges, a plus beside a cyan row, a pencil beside a row with one darker cell and a trash can beside a dashed empty row, above a plain gray row, while a cyan bracket gathers the three badged rows and forks to two small blue tables on the right
ArcPy

Mirroring a weekly CSV drop into an enterprise geodatabase — truncate-and-reload or a differential edit, and the documented rules that choose for you

Esri documents no single ArcPy pattern for mirroring a full weekly CSV drop into a registered enterprise geodatabase table, only building blocks. Versioning, data ownership, attachments, relationship classes, row identifiers and archiving decide between truncate-and-reload and a differential edit for you. The rules, three Pro 3.7.1 traps — CSV type inference, an Append upsert that duplicates rows, cursor edits outside an edit session — and a mirror script that designs around them.

September 17, 2026 · 17 min read · Data loading
A card of geometry primitives on the left, holding a pentagon, a point, a polyline and a dashed buffer ring, fans out to six rounded operator tiles each badged with a small ring; the tiles feed a card where a dashed spinner downloads into a blue cube, then a solid arrow runs through a completed buffer tile to a map panel showing a cyan buffer disc under a blue check mark, while a dashed gray branch from the cube card passes through a crossed out node to a pale message card whose exclamation icon sits beside two blank gray text bars
Maps SDK for JavaScript

Migrating to the geometry operators — the load() call nine of them need, and the error that names nothing

geometryEngine is deprecated and the geometry operators replace it, but the migration is not a rename. Nine of the 52 operators will not run until you await load(), with an error that names neither the operator nor load(), and the other 43 have no load() at all. Which nine and the rule that predicts them, what load() downloads, the planar buffer that quietly measures in degrees, and the misspelled module name that hangs instead of failing.

September 16, 2026 · 9 min read · Migration
A map panel on the left where a dark casing seam cuts straight across the lighter road at the crossing, an arrow to a cross-shaped road symbol pulled apart into its two layers with the white fill lifted above the gray casing, a vertical reorder control with up and down arrows around a stacked-layers glyph, then a second map panel where the junction runs through unbroken and carries a check mark, a separately check-marked overpass on piers below it, and a column of three map thumbnails at progressively smaller scales beside a two-row draw-order list
Maps SDK for JavaScript

symbolLayerDrawing and alternateSymbols — cased roads that hold together at the junction

A cased road symbol is two symbol layers, and by default every feature paints both of them before the next feature starts — which is why the junctions look right in Pro and wrong in the browser. What symbolLayerDrawing and alternateSymbols actually change at 5.1, why the strings in drawOrder are a contract you should read rather than guess, the paired-layer workaround this retires, and the four limits to plan around.

September 7, 2026 · 13 min read · Cartography
A parcel table and database on the left feed a funnel into three map panels of a parcel grid, first thinned at the source, then bounded by a dashed selection box, then dimmed so only the matches read at full strength, with a row below of three check-marked tokens and one crossed-out result card, ending in a verified summary card on the right
Maps SDK for JavaScript

definitionExpression, filter, featureEffect — and the feature count you can actually quote

Three properties all narrow a feature layer and they are not interchangeable. definitionExpression changes what reaches the browser, filter changes what draws out of what already arrived, and featureEffect only changes how it draws — and none of them is a security boundary. Plus the three layer view flags that decide whether the count in your results panel is a fact or a guess, a worked results-panel build, and the fourth lever most articles leave out.

August 31, 2026 · 16 min read · Filtering
A map layer card with a lock badge feeds a panel of three watcher rows, marked by a filter, a table and a shield, which branches to three map result cards marked by an eye, an edit pencil and a share icon, each with a progress bar at a different stage.
Maps SDK for JavaScript

reactiveUtils in Maps SDK JavaScript — watch, when, whenOnce, and the handle you forgot

watch, when, whenOnce and on look like synonyms and are not. The subscription failure that throws in your console versus the one that is genuinely silent, the already-true trap in when, and the two-line React pattern that stops a component leaking a subscription every time it remounts.

August 25, 2026 · 11 min read · Reactivity
A rectangle dragged across a map view, separating the features currently drawn beneath it from the much larger dataset still sitting in the service behind it
Maps SDK for JavaScript

Drag a box over the map — what rectangle hit testing actually returns in Maps SDK 5.1

5.1 lets hitTest take a screen rectangle, and adds fetchPopupFeatures to the map, scene and link chart components. Both answer a display question, not a data question — the count has to come from queryFeatureCount, not the length of a capped array. The rotation-safe geometry, the sibling layer view properties, and the 6.0 deprecation clock.

August 24, 2026 · 12 min read · Selection
A folder of Python scripts and toolboxes passing through a static analysis pass that separates the files which still run from the ones that need a fix before an upgrade
ArcPy

Pro 3.7 closes your cursors — find the scripts that break before you upgrade

ArcGIS Pro 3.7 invalidates an arcpy.da cursor the moment its with block exits, so any script that called reset() or re-iterated afterwards now raises ValueError. Why the old behavior was the bug, the two shapes it takes in real code, plus two free tools: one that audits a whole scripts folder before you upgrade, and a safe template for the pattern that replaces it.

August 20, 2026 · 10 min read · Free downloads
An inspection form assembling text fields, a multiple-choice element and a photo attachment element into a single feature record written back to a hosted feature layer
Maps SDK for JavaScript

Attachments belong in the form — and 5.1 hides them behind three defaults

Maps SDK for JavaScript 5.1 makes attachments a real form element, with Arcade-driven visibility and generated filenames. Three defaults hide it, and a keyword rule can hide every attachment you already have. The working code, the credit math, and the traps.

August 19, 2026 · 10 min read · Editing
A columnar dataset in a cloud store passing through geographic clustering and a multi-scale index so a map view streams only the features inside its current extent
ArcGIS Online

Stream only what the map needs — Spatially Optimized Parquet feature layers

Parquet feature layers put an open GeoParquet dataset behind an ArcGIS map and stream only the bytes the current view needs — geographic clustering plus a multi-scale index, no tile cache and no hand-built generalizations. The working ParquetLayer code, Data Pipelines entitlement and credit cost, and the five beta constraints that disqualify a project before design starts.

August 18, 2026 · 10 min read · Data Engineering
A map application showing points of interest found near a location with a place details panel
ArcGIS Location Platform

Find what’s nearby — the ArcGIS Places service, from search to place details

The ArcGIS Places service searches businesses and points of interest worldwide, filters them by category and text, and returns per-place detail down to phone, website, and social handles. How nearby search works, the price-group billing model, and working Maps SDK for JavaScript code.

August 17, 2026 · 8 min read · Places
A scanned paper map being converted into clean vector line features in ArcGIS Pro
ArcGIS Pro

Vectorize scanned maps in one tool — Extract Scanned Lines and Polygons in ArcGIS Pro 3.7

ArcGIS Pro 3.7 ships two purpose-built geoprocessing tools that turn scanned map linework into clean vector features — intersections, gaps, noise, and smoothing handled in the extraction itself. What they replace, the parameters that decide output quality, and the licensing catch.

August 11, 2026 · 7 min read · Geoprocessing
A map application window with a chat assistant panel answering questions about the map
Maps SDK for JavaScript

Talk to your web map: the Maps SDK’s new AI components (beta)

Maps SDK for JavaScript 5.0 ships AI components (beta): an Assistant chat component plus navigation, data exploration, and help agents that answer natural-language questions against your web map. How to wire one up, why your web map is the real prompt, and the access rules to check before you demo it.

August 3, 2026 · 8 min read · AI Components
The arcgis.mapping module splitting into the new arcgis.map and arcgis.layers modules in ArcGIS API for Python 2.4
ArcGIS API for Python

Migrating to the new arcgis.map module in ArcGIS API for Python 2.4

The 2.4 release removed the arcgis.mapping module and deprecated the WebMap class. What breaks in your notebooks, the WebMap-to-Map property mapping, the new arcgis.layers Service class, and a clean six-step migration path.

July 27, 2026 · 8 min read · Migration
A terminal window generating a project folder structure beside a browser window showing a finished map application
Maps SDK for JavaScript

One command to a working ArcGIS app: the @arcgis/create CLI

Esri ships a scaffolding CLI for the ArcGIS Maps SDK for JavaScript — one command generates a Vite, React, Angular, Vue, Webpack, CDN, or Node project with the SDK, Map components, and Calcite wired. The CSS trap that bites half-migrated apps, and what to add before production.

July 20, 2026 · 8 min read · Tooling
One source feature layer feeding multiple filtered view layers, each serving a different audience
ArcGIS Online

One layer, many audiences — hosted feature layer views in ArcGIS Online

One authoritative dataset, three audiences — and every exported copy is a governance failure waiting to happen. Hosted feature layer views serve filtered, field-limited slices of a single layer, each with its own sharing and editing rules.

July 13, 2026 · 8 min read · ArcGIS Online
A session pass covering a grid of map tiles - the basemap session usage model on ArcGIS Location Platform
ArcGIS Location Platform

Stop paying per tile: basemap sessions on ArcGIS Location Platform

Per-tile billing makes your most engaged users your most expensive ones. Basemap sessions cap the cost — one session, unlimited tiles for up to 12 hours — and since Maps SDK for JavaScript 5.0 it’s one config block.

July 6, 2026 · 8 min read · Basemaps
A Calcite app window being re-skinned by a brand color token
Calcite Design System

Brand a Calcite app the right way — theming ArcGIS apps with design tokens

Hard-coded CSS overrides break on the next Calcite release. The durable path: override semantic design tokens once at the root, theme light and dark together, and reach for component tokens only for the last 10%.

June 29, 2026 · 8 min read · Theming
ArcGIS Maps SDK widgets being deprecated, replaced by map components
Maps SDK for JavaScript

All widgets are deprecated in ArcGIS Maps SDK for JavaScript 5.0 — your move to map components

5.0 deprecated every widget; components are the recommended path. What still works, the one-line CDN change, and a calm migration plan before removals begin in 6.0.

June 24, 2026 · 8 min read · Migration
Inside a browser window, an old gray API key passes by arrow to a new blue key ringed by a rotation dial
ArcGIS Location Platform

Legacy ArcGIS API keys retire June 27, 2026 — what breaks, and how to migrate

Legacy keys are revoked June 27. What breaks (silently), and the step-by-step move to API key credentials — including the Online vs Location Platform privilege split.

June 22, 2026 · 7 min read · Security & Authentication
A web map sheet whose pixelated left half turns into crisp vector map lines on the right
Maps SDK for JavaScript

Why your web-map PDF export looks blocky — and three ways to fix it

A decision tree from client screenshot, to Esri’s ExportWebMap print service, to a custom serverless render service.

June 8, 2026 · 9 min read · Architecture
An app window where a map pin opens a details panel beside the map
Maps SDK for JavaScript

Render an Esri popup in a React panel without it vanishing

The Feature widget silently detaches its container in React. The fix: hand Esri a raw div that React never tracks.

June 1, 2026 · 8 min read · React
Glowing modular geoprocessing tool tiles in brand blue
ArcPy

One ArcGIS Pro toolbox, every project: the .pyt + Favorites pattern

Ship your house tools into every project via a git-tracked .pyt pinned through Favorites — a git pull is the whole update story.

May 25, 2026 · 8 min read · ArcPy
A sync arrow cycling layer, field and chart icons into an app window holding a data dictionary grid of layers, fields, domains and counts
ArcGIS API for Python

A self-updating data dictionary for ArcGIS Online

Crawl your account with the ArcGIS API for Python into a multi-sheet Excel inventory: services, layers, fields, coded + range domains, counts, SR. Free notebook + Pro tool.

May 18, 2026 · 8 min read · Free download
A blue map-marker symbol opened into its vector outline with editing handles, beside a drawing toolbar and a web page card showing the same marker
ArcGIS Pro

Export ArcGIS Pro symbology to SVG: reuse your cartography on the web

A .stylx is just SQLite and a symbol is CIM JSON — so you can export Pro symbols to crisp SVG (and PNG) with no arcpy. Free notebook + Pro tool.

May 11, 2026 · 8 min read · Cartography
Glowing grid of cartographic map thumbnail cards in brand blue — automated ArcGIS Online thumbnails
ArcGIS API for Python

Stop letting ArcGIS Online pick your thumbnails: brand every item with Python

Your content gallery is the cheapest branding surface in ArcGIS. The full workflow — template, SVG anatomy, and the ArcGIS API for Python batch job — that restamped 355 items in one run.

May 4, 2026 · 9 min read · Automation

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