https://kfdani-001-site10.gtempurl.com/index.php?action=history&feed=atom&title=OpenSite%2FGuides%2FUse_the_expression_editor 2026-10-30T02:50:43Z Revision history for this page on the wiki MediaWiki 1.46.2 https://kfdani-001-site10.gtempurl.com/index.php?title=OpenSite/Guides/Use_the_expression_editor&diff=951&oldid=prev 2026-10-29T22:08:24Z

<p>Add source-reviewed, step-by-step OpenSite user workflow</p> <p><b>New page</b></p><div>__NOTOC__<br /> {{OpenSite scope}}<br /> {{OpenSite lesson<br /> |id=opensite.help.use-the-expression-editor<br /> |summary=Choose a native formula or a Python expression deliberately.<br /> |prerequisites=A practice expression-capable field and a saved checkpoint. Python mode requires the matching Python-enabled host.<br /> |steps=<br /> === Open the expression affordance ===<br /> Select the quantity/expression-capable field and use its &lt;code&gt;...&lt;/code&gt; expression button. Read the evaluated value beside the field; the dialog edits the source, not only its formatted display.<br /> <br /> === Choose the language ===<br /> Use Formula for the restricted unit-aware expression language. Use Python only for trusted code requiring its Python context. These are different languages: native &lt;code&gt;if(cond, a, b)&lt;/code&gt; is not Python syntax.<br /> <br /> === Preview deliberately ===<br /> Check destination units and dimensions. Native formula preview can validate the proposed calculation. Python preview is explicit; ordinary field refresh does not silently execute Python. An error is a reason to correct the expression, not ignore it.<br /> <br /> === Apply and verify ===<br /> Accept a valid expression and compare its result with an independently known value. The [[OpenSite/Guides/Native property formulas]] and [[OpenSite/Guides/Python property expressions]] lessons provide checkable examples.<br /> <br /> === Enable Python only for a trusted document ===<br /> Loading retains Python source without automatically running it. Use {{MenuCommand|Edit → Enable Python Expressions}} and then {{MenuCommand|Edit → Recalculate Python Expressions}} when appropriate. A busy interpreter, exception, cancellation, incompatible result or stale revision can reject evaluation.<br /> <br /> === Remove an expression intentionally ===<br /> Use the dialog’s removal/literal workflow when you mean to replace the relationship. Cancelling or accepting an unchanged literal should not be used to erase a stored expression. Recheck the property afterwards.<br /> |result=You can tell which language is stored and whether its evaluated value was accepted.<br /> |limitations=Python expressions are trusted code, not a security sandbox. Tables/cell references are not available in this baseline.<br /> }}<br /> <br /> == Continue learning ==<br /> [[OpenSite/User manual|User manual]] · [[OpenSite/Tutorials|Tutorial pathways]] · [[OpenSite/Support|Get help]]<br /> <br /> &lt;div class=&quot;os-page-nav&quot;&gt;{{Docnav|OpenSite/Guides/Edit typed properties|OpenSite/Concepts/Documents and identity|OpenSite/User manual|User manual}}&lt;/div&gt;<br /> [[Category:OpenSite documentation]]</div>

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