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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 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
Featured · 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

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A single Accessor property on the left feeding four colored observer wires to the right — watch fires on every change, when fires only when the value becomes truthy, whenOnce resolves once as a Promise, and on relays a DOM-style event — each ending in a handle whose remove() call is highlighted
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
Glowing holographic key over a blue topographic data network — ArcGIS API key migration
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 crisp printed map sheet over a blue cartographic surface
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
A floating map info panel hovering over a blue terrain 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
Glowing holographic data grid and schema columns over a blue topographic field
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
Glowing cartographic map-marker symbols as vector wireframes over a blue topographic field
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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